All posts by Terry Wright

Editor, Loose Fillings. Author, Power Without Glory: Racing the Big-twin Cooper

STARTING THE BEAST

By Garry Simkin

Long the bane of air-cooled cars has been the starting of these things. In early days one relied on a couple of healthy pushers to get your beast up and running, but inevitably, just at the time that you needed that push, they had wandered off. Or they didn’t get up enough speed, didn’t understand about bringing the engine back onto compression, or just gave up. Towing wasn’t always an option given confined spaces, but sometimes a hill climb offered a downhill run to the start line which sufficed.

In the early 1990s when I resurrected my JBS Norton I figured that there had to be an easier way, so I cut up some square tube, fired up the TIG welder and got to work making a starting machine using two four-inch rollers and a hefty Nippon Denso starter motor. This worked well as I could start the car on my own so no assistance was needed. Others liked the idea and I ended up making about 15 of these devices. Whilst making life easier at race meetings some assistance was still needed to lower the ‘’hockey -stick ‘’ jack under the other wheel and get you off the rollers and on your way.


In time various people experimented successfully with onboard starter motors on the air-cooleds and in due course Terry Wright fashioned an automatic transmission flex plate onto his JAP twin drive sprocket and used a chassis mounted reduction starter on his Walton JAP. Brian Simpson made a similar arrangement for his Mk 9 Cooper JAP 1100 which works well. Fellow Mk9 Cooper Norton owner Grant Cowie then turned his hand to fitting a starter to his car, using a Harley Davison ring gear adapted to the Norton clutch sprocket which worked well and looks like this:

This inspired me to attempt the same thing with my Cooper Norton and a Harley 84 tooth ring gear was slimmed down and adapted to the NEB clutch (which we use here instead of the original Norton type – Ed) sprocket, and uses a modified Japanese car starter sitting above the gearbox. Adjustment with regard ring gear mesh had to be provided for when the gear box is moved fore and aft to alter chain tension. It looks like this in the car.

New ‘hockey stick’ shaped plates running from the ‘’triangle’’ at the back axle and connecting the top of the Norton box and on to the chassis had to be profile cut and modified to hold it all together. A lot of work for sure but one push on the starter button has it running, and once again no outside assistance is needed.

The motor is a 1.5kW reduction unit from CAE Performance Products in Chewton, Victoria and can be seen running on our Facebook page as we haven’t worked out how to embed it here.

Grant Cowie is running a light weight on-board battery with an isolator switch, but at this stage I will opt for using an Anderson jump plug and remote battery to fire it all up. An aluminium cover over the starter pretty well hides it. Its a lot of work, but as we get older we need to make life easier for ourselves. GS.

Loose Fillings editor Terry Wright adds some notes on his experience…

My approach only a few years back was a little different to Garry’s which has the starter motor cleverly mounted above the gearbox and driving the clutch assembly. For the Walton-JAP, with a new-build 1270cc reproduction of the 8/80 JAP Bruce first had in the car, I chose to drive the engine mainshaft from a forward-mounted motor on the mountings that once housed a supercharger. I made up a double main sprocket using a ‘flexplate’ from a little Daihatsu which was screwed to the drive sprocket on the mainshaft with a suitable spacer. The starter motor supplier Hi-Torque in Victoria provided a gear on the motor to suit the teeth on the flexplate. Installed it looks like this:

Knowing no better, I picked the biggest race car starter motor in the store, which was sufficient to start a V8 race motor. Almost certainly this was overkill and unnecessarily heavy, but boy, did it go! It went so well that I wondered if it was responsible for my first attempt at a pressed-up flywheel assembly shifting fractionally. Everyone I consulted said ‘no way’. Not being entirely convinced I collaborated with engine-builder Greg Summerton in South Australia and engineer Roald Pedersen in Norway who had access to some modelling software to do various calculations and the tentative conclusions were that everything was alright.

The above jumble of engine stuff is masked as below by a cowling in the same shape as the fuel saddle tanks that Bruce Walton used.

The new pressed-up crankshaft that Greg made has shown no sign of shifting under the starter load and is smooth as silk in operation. Garry says he has found no need to retard his ignition for starting but with the programmable Harley Davidson ignition I adapted to the JAP I was able to set the ignition advance to zero for rpm up to 500.

For the record, the motor I used was rated at 2.5hp or 1.9kW. So I can say with certainty that a 1.9kW starter is fine with a big-twin and 1.5kW works on a Norton or other single cylinder engine as Garry has been using. Note though that Garry is driving his crankshaft via the primary chain so think about how this change of gearing gearing. Whether the weight and cost savings of a smaller motor would be satisfactory remains to be established. Maybe someone would like to have a go and let us know?

MORE ON THE LAWRANCE ENGINE

From Brian Thorby who has restored one which was also once
destined for a UK 500cc car but never quite made it.

1943 Lawrance Series 30 Auxiliary Power Unit (APU) Air-Cooled Engine and DC Electrical Generator

This 500cc (30 cu in) twin-cylinder air-cooled ohv engine was close-coupled to a 5Kw 28 volt DC electrical generator in line with the crankshaft. The complete installation was mounted within a sound-insulated casing aboard several types of WWII allied aircraft to provide on-board electrical power independent of the main engines. This unit would have been installed in Consolidated Catalina  Mk I & Mk IVb Flying Boats, operating from Woodhaven by Wormit on the Tay Estuary.

On 10 May 1943 1477 (Norwegian) Flight RAF, manned by Norwegian aircrews who had escaped the occupation of Norway in 1940, arrived in Fife to fly D.H. Mosquito fighter-bombers at Leuchars, and Catalina Flying Boats based on the Tay at Woodhaven. The Mosquito crews were  moved to join the Banff Strike Wing in Morayshire in September 1944, leaving the Catalinas as a detachment of 210 Squadron Coastal Command RAF. The first Flying Boat, Serial W8424, alighted on the Tay on 18th May 1943, and was named Vingtor. Until 1945, these long range anti-submarine and reconnaissance machines performed valuable anti-U-Boat escort for convoys, and also ferried personnel in and out of occupied Norway, where the crews’ intimate knowledge of their homeland came into play.

On these long flights of up to eight hours duration the Lawrance APUs droned away at an amazingly fast speed of 4,000 rpm. When peace came in 1945, the Catalinas were flown to Oslo as 333 Squadron, passing to the control of the Royal Norwegian Air Force. The PBY Catalina remained in Norwegian service though various marks until 1961, until a suitable replacement long range coastal patrol aircraft was available. These aircraft would have flown overhead Montrose on virtually every flight from Woodhaven during the war. The people of Wormit, close by to Woodhaven Pier, have maintained contacts with Norway in memory of their wartime visitors who fought bravely in exile until their homeland  was liberated.

In emergency, besides charging batteries and powering communications equipment, the APU could also power bilge pumps, in the event of the PBY’s hull being holed by enemy action or striking submerged objects. The engine is designed and constructed on typical aviation principles with twin magneto ignition systems; high-specification materials and finish. The compression ratio of 9: 1 is very high for a stationary engine, but was specified to suit high octane aviation fuel. A five cylinder radial-layout version was supplied for use on American B-24 Liberator Bombers, used by RAF Coastal Command as well as by their own USAAF Squadrons.

This Type 30D Lawrance APU engine was restored by Brian Thorby of Brechin during 2009, as a loaned exhibit for Montrose  Air Station.

From MASHC TECHNOTE No. 007

What happened to the Lawrance 500?

An interesting addition to Loose Fillings’ ever-expanding knowledge of air-cooled cars in Australia and elsewhere has emerged with a letter, photographs and a press cutting which have been sent to us by once Melbourne, now Perth resident Allan Ould.

‘I served my apprenticeship as a motor mechanic with Peter Menere in Brighton, Melbourne’, Allan writes. Peter Menere Motors was always full of interesting European cars, including racing cars such as Bugatti, Cisitalia, Lombard, and later ones such as Cooper Bristol, Alta and BWA. We also prepared cars for the early Armstrong 500 races at Phillip Island and the Mobil Economy runs.

‘My enthusiasm for motorsport was further encouraged when I joined the 500cc Car Club. It was a revelation to meet people like Phil Irving, Charlie Dean, Murray Rainey, Bruce Walton, George Wade, Paul England and many more.

‘As soon as I was legally able to, I had my first taste of competition driving with Ron Edgerton’s BWA at the Templestowe Hill climb. Thus began a lifetime involvement in competitive motor sport. A friend who lived nearby (Bob Minogue) had bought the “Sidney Rudge” and I became interested in building my own 500cc race car.

‘I had become friendly with Murray Rainey, who was a brilliant driver, a very good engineer and a great person. He regarded being diminutive as something of an advantage in terms of being a “lightweight driver” and he made good use of that. His supercharged Cooper Norton was a sight to behold (and to hear) at Fisherman’s Bend. An interesting aspect to that car was the debate between Murray and Phil Irving in that Phil maintained that ‘Blown Nortons’ didn’t work well and Murray was determined to disprove that (which he did), winning the first race at Phillip Island (below)

‘Murray had in mind a project for a hillclimb car and had gathered parts for it before he decided to concentrate on other projects. In about 1960, I bought the parts from him for what was to become the ‘Lawrance 500’. These included a 500cc ohv Lawrance engine which was US-made and originally used as the engine for a ground generator (or APU) in a Catalina flying boat. The engine was beautifully made to aircraft standards, twin magnetos, two plugs per cylinder etc, but designed for reliability, not maximum power (below).

 ‘Murray had fitted a Roots-type cabin blower as a supercharger and added an SU carburettor, but had not developed the engine further. Also included were a modified ‘WD’ BSA gearbox and a final drive made up of some Ford Popular parts and special castings.

 ‘With great enthusiasm (and a lot of reference to the Costin and Phipps book “Racing and Sports Car Chassis Design”), I built a chassis Jig and proceeded to build my first race car. Eventually I was to learn that the real lesson from building the car was that this young man had a lot more to learn about racing car design and race engine development.

‘With the car completed in 1962, I turned to the not inconsiderable task of trying to develop the engine to produce hoped for horsepower. The combinations of unknown optimum cam profiles, ignition timing, 12 lbs + boost and jetting for methanol, presented a challenge to say the least. I do still remember sitting down with George Wade in deep discussion about cam profiles! It would be hard to access such knowledge, freely given, in this day and age!

Testing at Fishermans Bend (above and the finished engine, blower and gearbox installation (below)

‘There were endless test days at Fishermans Bend airstrip, with handfuls of needles and jets just to get the engine to run reasonably, but full success was never achieved. Fortunately, these were in the days when you could access the airstrip just by flicking the chain off the gate, so we weren’t paying for circuit hire

Front view of the finished car

‘I also clearly remember driving through the pits at Winton (which were pretty rough then) and feeling the chassis flex. That was my first lesson re weight vs torsional rigidity in good chassis design.

‘Some months after finishing the car and having raced it only a few times, I began a job with General Motors which entailed a lot of traveling and I didn’t ever have a chance to sort the car out. I sold the car (I think in 1963) at about the time I began work at GMH. At that point I lost track of the car, as I was away from Melbourne for most of my time.

 ‘After a couple of years with GMH, I fulfilled an ambition to work full time in top level motor sport and travelled to England where I worked for several years on the Brabham F2/ F1/ Indy and Tasman teams. Due to having the opportunity of working for that brilliant designer, the late Ron Tauranac, the young man eventually learned a LOT MORE about racing car design, (and engineering in general).’

So, dear Loose Fillings readers, do any of you know what became of the car? It must have been too good a chassis not to have survived for some time, maybe with a four-cylinder engine fitted? We would be interested to hear, perhaps via our Facebook page.

CAMS

OR THE BLACK ART OF VALVE TIMING.

“I have a question”, writes our correspondent Demon Tweeks … “What’s a good all round valve timing for a Cooper JAP for sprints, hillclimbs and short circuit racing?”

 Good question! But perhaps a more important enquiry might be this one. How good are the standard JAP factory speedway cam, for those three forms of competition?

The answer is … VERY good!  Which begs the next question. What are the real valve timings of a Speedway JAP? 

Here’s where it gets interesting, because although we are given when we try to replicate the factory valve timing figures in JAP manuals, we seldom get even close. As Professor Sumner Miller famously used to say.’ Why is this so?’

Happily, there is a logical explanation for the variation between what the factory says the valves should be doing, and what our best investigative efforts sometime produce. This is because the manufacturer very seldom if ever, tells us what tappet clearances were used to establish their published valve timing figures!

That means if we want to replicate factory timings, we have to try to work out ourselves what tappet clearance they used, and because there are so many options, doing that can take up a lot of viewing time, so it’s easier to go back inside the house where it’s lots warmer.

So, we must ask … Is there a universally accepted tappet clearance that we can use for comparing valve timings. The answer is both YES and NO! 

YES, because most modern camshaft grinding firms quote valve timing figures based on 50 thou tappet clearances, (or lash as the Americans say). This makes direct timing and comparisons of camshafts easy……but 50 thou! That seems an awful lot! Why 50 thou?

The clearance of 50 thou is chosen because good camshafts are ground on the opening and closing sides of the lobe so that for up to 30 degrees of crank rotation, the valves are only GENTLY lifted a few thou off, and lowered onto their seats. You can’t see them but the cams have ‘quietening ramps’ both side of the lobe. This means if we check our valve timings with NO or little tappet clearance, we will get greatly extended opening periods, which will almost certainly make nonsense of any published timing figures we might be trying to replicate.

So, to eliminate this confusion, modern camshaft experts mostly use 50 thou tappet clearances for reference. But since we are working with camshafts that were ground 70 years or so ago when this technology wasn’t universally used, that’s not much use to us. Thus, the question remains unanswered. What checking tappet clearance did Mr. JAP use when he published valve timing figures for his Speedway engines in 1950 and will we ever know?

Perhaps we might! Because there is good news to hand! Working together and combining their genius, Miss Marple and Hercule Poirot discovered by trial and error that if we set our checking tappet clearances to 20 thou all is revealed! 

The following published valve timings for a Speedway JAP now make sense!      

INLET Opening 44 BTDC.  Closing 62 ATDC.
EXHAUST Opening 65 BBDC. Closing…34ATDC.  

This is a major breakthrough! Now we know what the manufacturer did. Their checking tappet clearance was 20 thou! Now we can do the same. We can set our JAP tappets at 20 thou. and play around with the various keyways until we get as close as we can to the factory JAP valve timings, which we know from experience give a really wide spread of power all the way up to 6000 RPM…… Bingo!

But the serious racer is never satisfied! Is there a better cam? Something with more overlap? More lift?  There is always the temptation to try something different.

As JAP speedway engines became less competitive internationally, JAP concessionaire George Greenwood introduced a new short-stroke engine with a camshaft which had been around for quite a while and had significantly broader valve timing. This was variously known as the Special or 84S cam and the temptation to try it out in our Cooper car was irresistible!

The published JAP timing figures for this camshaft were…

INLET Opening 60 BTDC. Closing 80ABDC.  
EXHAUST Opening 80 BBDC. Closing 50 ATDC.

To get a better visual idea of the value of these numbers, just draw a circle freehand and divide it in quarters with a horizontal and a vertical line. Now mark TDC at 12 o’clock and mark on the circle the approximate degree positions of the two sets of timings given above for comparison. We see immediately the 84S camshaft has 110 degrees valve ‘overlap’ at TDC against 78 degrees.

And how did these two quite different JAP camshafts compare in performance when installed in the same engine and in the same Cooper car by Demon Tweeks? 

The only really good thing we could say about the 84S cams was that they gave the engine another 500 maximum revs through the gears and in a straight line, but that was their only advantage. Missing was the easy starting and the beautiful flexibility of the early cams which allowed the engine to pull in any gear without the necessity of slipping a fragile clutch and /or changing down half-way through a corner.

On the race track there was little difference in lap times between the two camshafts as long as the track was dry. But if the track was wet, the later model’s peaky cams made survival much less predictable! This was demonstrated at a wet Wakefield Park, Australia meeting where Brian Simpson’s MK9 Cooper with standard factory cams had Chas McGurk’s 84S-engined Mk6 for lunch!

So there we are. Standard speedway cams are definitely the go.

Over the years that your correspondent was learning all this, your editor Terry Wright was also investigating the cams used in his ex Bruce Walton cars, blown and unblown, and can add more on the subject of camshafts and their individual characteristics –  the good, the bad and the ugly. He will do this in a future article.

In the meantime, ponder the fact that no JAP material appears to make any mention of a 20thou checking clearance!

Demon Tweeks

SLOWING DOWN COOPERS

by Demon Tweeks

The dimly lit workshop is cluttered with bits of old Cooper racing cars. 

It is nearly midnight. Outside it rains heavily. Two elderly men are seated on empty 20 litre drums staring at a MK6 Cooper JAP with the right front wheel removed.

The bald one, approaching a hundred, speaks softly to his old friend and confidant Uncle Des.

“You know something Desmond?” Chas McGurk mutters sadly, “these Coopers should stop a whole lot better than they actually do!”

Revived by a recent Mars Bar, Uncle Des shows interest in Chas’s surprising statement.

“What do you mean?” Des quizzes. “I thought they had pretty good brakes!”

“Not really,” Chas goes on. “Our Coopers weigh less than 400 kilos with driver and fuel. They have 8 wheel cylinders, 8 leading shoes, working in 4 good cast iron linered drums with 2 master cylinders!

coop brakes 001

coop brakes 002

Above: Mk6 Cooper brakes as Des and Chas saw them

On paper that’s as good as you can get! They should stop on a sixpence……. but they don’t!  Even with really good linings we have to lean pretty hard on that brake pedal, much harder than you would expect.  It’s not a big problem at sprints and hillclimbs, but it’s a different story when you need to knock off a hundred miles an hour in a hurry at the Mallala hairpin.”

Anxious to help and always up for a challenge, Des leant forward carefully on his drum and asked for a torch. He studied the Cooper’s exposed brake set up for some time.

Impatient for a verdict Chas prompted him. “What do you reckon?” he said.

“I think it’s got something to do with the brake shoes,” Des said. “I don’t think they self- energize much…… or at all.”

“The brake shoes,” Chas repeated, seeking clarity, “what’s wrong them?”

Des took a deep breath and got started. “This is only a theory,” he warned, “but this is what I think. What we are looking on this car and most other Coopers, is a Lockheed twin leading shoe set-up straight off a Morris Major.  Is that right?”

“I believe so,” Chas nodded.

“Well,” Des continued, “let’s compare this arrangement to a typical Norton twin leading shoe brake. The Norton has both brake shoes located on the backing plate by fixed anchors at their trailing ends, so that when actuated they pivot outwards. As the leading edge of the linings makes contact with the rotating drum, a natural self -energizing action of the brake shoes takes place, and the result is a powerful effective brake!” 

Chas, who was following Des’ dissertation with great interest nodded. He was right on it!

“But that’s not what’s happening here,” Uncle Des went on. “The shoes on the Cooper are not fixed. They are floating! They move around. They don’t pivot, and when these brakes are applied and the lining makes contact with the drum, instead of energizing the leading edge of the shoe like the Norton, I reckon these shoes simply slide in the direction of drum rotation and wedge the trailing end of the shoe against the blind end of the opposite cylinder.”

Silence followed Uncle Des’s hypothesis. “And you reckon,” Chas said after considerable thought, “that the self- energizing effect of this form of leading shoe arrangement is minimal?”

“I would make so bold,” Des admitted shyly, “to suggest the trailing end of the shoe could be doing most of the braking.”

Chas exhaled slowly. “That’s a big statement,” he grinned.

“I will give you supporting evidence,” Des continued confidently.

“If you Google Lockheed Brakes of this design you will find this proud boast. Lockheed state, and with some emphasis, that this design is a ‘Non- grabbing brake!’

“Now what does that suggest? The logical inference is that it has little self- energizing tendency! And something else! Do you remember those good looking twin leading front brakes Triumph and BSA put on their bikes in the 70s? They used exactly the same Lockheed shoes that are on the Coopers! The only difference was they were mechanically operated.”

Chas nodded knowingly. “They looked good,” he said, “but they were a hopeless bike brake.”

The two seniors lapsed into a reflective silence. Then Chas asked the $64 question. 

“Should we tell anyone about this? And would they believe us? I suppose we could run it past Brian and Garry and Steve and Terry and see what they think? They’ve all got one of these things at home.”

“And while we are talking,” Uncle Des interrupted, “there’s something else weird about these brakes.”

“Please don’t tell me,” Chas said, shutting his eyes tight so he couldn’t hear. “What?”

“Have a look at these wheel cylinders,” Des said. “Notice anything odd about them?”

Chas gave them the once over. “No,” he confessed. “I can see they are early Morris 7/8” single ended Lockheed brake cylinders, but what’s odd about them?”

Uncle Des prodded a nearby cylinder with his Phillip’s head screw-driver and said, “They’ve got no bleeder screws,” and handed Chas the torch for a closer look.

Chas checked. Des was right! Eight brake cylinders with no bleeder screws! The brake hose supplied oil to a brass union on one wheel cylinder which fed an external pipe to another brass union on the other wheel cylinder. The only bleeder screw present was screwed into the last brass union at the end of the line making it possible when bleeding for fluid to completely bypass the cylinders!

Chas shook his head as he tried to work it out.

Des helped clear his thoughts with a brief summary. “The way this is plumbed,” he said patiently, “means that when you bleed the brakes, it’s very difficult to get all the air out of the cylinders, because there’s only one hole in the cylinder and that’s where the brake fluid enters. With no separate bleeder screw, any trapped air will be trying to get out through the same hole as the oil is trying to get in! Right?”

Chas worked on it for a minute and then gasped, like when Archimedes discovered why boats float.

“That’s why it’s so hard to get a decent pedal when you try to bleed these brakes, and why you’ve got to adjust the shoes up tight to get the wheel cylinder pistons right in, and clamp off the hoses and bleed one wheel at a time, and kick the pedal hard and fast. And what makes it worse, the cylinders all point in different directions. Up, down and sideways. And remember these cylinders were ever only used on the Morris front wheels in a horizontal position.”

There was another long silence. It was longer than usual. Uncle Des and Chas looked at one another.

They were both thinking the same thing. ‘Why do we do this to ourselves?’

They smiled as they said ‘Goodnight’.

 

The Lynx Vincents

Kerry Smith looks at Sydney’s LYNX ENGINEERING and the LYNX VINCENTS in the first of three articles.

In the June 1957 issue of Sports Car World, an article titled The Racing Ralts  by Alan Gibbons featured the racing cars then being constructed by Ron and Austin Tauranac. Detailed was the last Ralt built in Sydney (#4) which was a rear-engined Cooper-style car with a 998cc Vincent engine. Ron raced it sporadically before selling it to Ossie and Noel Hall and then to Reg Mulligan who raced it regularly.

Between late 1957 and early to mid 1960, the Tauranacs produced a limited number of Ralts for clients, making five or maybe six chassis on their jig, before Ron joined Jack Brabham in the UK. Peter Wilkins, who had worked with Ron making chassis, fibreglass bodies and seats, alloy wheels with integral brake drums and steering and suspension gear bought the stock of parts.

Wilkins then sold this pile of Ralt goodies to John Bruderlin and Leon Thomas on Parramatta Road, Concord, Sydney. The pair specialized in racing very potent MG specials as well as selling MG parts from cars that they wrecked. Wilkins also joined the firm as a partner to help construct racing cars for the new Formula Junior class that was taking off at the time.

One of the goodies was a Ralt chassis with a rear disc brake, Ralt wheels and a Vincent twin engine nestled in the rear. A picture of this featured in an article with photos of a number of air-cooled racing cars which was taken in Centennial Park for the March 1960 Sports Car World. This author is certain that this was what became known as Lynx Vincent #1. An advert for ‘Lynx Engineering’ in Sports Car World of October 1960 gave the new business’s name and address, and the following month there was a Lynx advert for “Formula 1,2,3 and Junior cars, along with racing components and frames.

Rear view of Lynx #1 in the company’s workshop. The blower mounted just in front of the engine can be seen poking out of the bodywork. Note the ‘flat’ leaf springs and drive shafts.

Lynx were to build three Vincent-engined cars which were well finished and potent vehicles. Later cars included the  Lynx BMC/FJ, the Lynx Peugeot and a number of Ford-engined Junior cars (along with a quick supercharged car and a couple of nice Borgward engined Juniors). There was  a relatively prolific output of cars from the factory over a period of probably two years at the most. They would have worked hard and smart.

How this hectic scene came about was probably due to Lynx utilizing the expertise of Peter Wilkins who later left to join up with Ron Tauranac and Jack Brabham constructing Brabhams in the UK. With Bruderlin’s and Thomas’ drive and expertise, along with the fabrication skills of Wilkins, electrician Phil Chittock and ex  motorcyclist Stan Smith who was an ace aluminium alloy worker, the factory turned out cars with a quality finish plus the requisite speed.

The first Lynx to race and cause everyone to take notice was car #1 as driven by ex Victorian John Marston. He had previously raced the ex Lex Davison supercharged Mk4 Cooper Vincent and the Mk5 Cooper Irving (Vincent). The first Lynx race was at the opening Warwick Farm meeting in December 1960 which is well remembered because of the extremely wet   conditions. The car was entered for John Bruderlin but for some reason Marston drove it; its performance was hampered by water getting into the engine. Marston then drove it for Lynx Engineering for the remainder of its time in Sydney.

Lynx #1, as we will call it, was a fairly simple design using contemporary Cooper and Ralt thinking, with a 998cc Vincent engine which was supercharged by a Roots-type cabin blower in the rear. There was a single disc brake on the chain driven back axle, a transverse rear leaf spring and lower wishbones. Ralt rack and pinion steering was used.

At the front were Ralt cast-alloy wheels with integral 8” brake drums and single, transverse upper suspension arms which had lower front wishbones and telescopic dampers. It mostly ran with Dunlop racing tyres. There was a fibreglass nose which was molded from a Mark 8 Cooper and a rear engine cover based on a T45 type Cooper with two large air scoops. It was painted mid blue. It was not a dissimilar design of car to the Davison Cooper Vincents or Bruce   Walton’s supercharged Cooper JAP Mark 8 –  a.k.a. the Walton-Cooper.

The front end of Lynx #1. Note the single upper suspension arms with coil springs and dampers

Through early 1961, the duo performed well at race tracks and more particularly the local hillclimb scene. Marston won the NSW hillclimb championship, just beating the late  Jack Myers in the tangerine Thunderbird (twin S/C Triumph engines in a Ralt chassis). The Lynx was track tested at the Warwick Farm short circuit in early 1961 by Sports Car World’s Ian Fraser who was quite impressed by its performance.

In mid 1961, Lynx sold the now slightly tired #1 to Les Trim of Narrandera (NSW) who raced it consistently for a while at the country circuits of Victoria and NSW (including Hume Weir and Catalina Park). The car entered another phase when it was sold to a Victorian farmer, John Richardson. It featured in an SCW article in Aug/Oct 1978 by Noel Tuckey.

John Richardson fitted a S/C Cooper S engine/gearbox in the rear and clothed it in a Goggomobile  Dart body and renamed the car RAB 2. The BMC power plant was replaced with a 179 Holden engine and VW gearbox. A Lola T70 front body was fitted with a Repco headed ‘grey’ Holden engine as a replacement. Then came new body work with a 3.3 litre Falcon engine and finally a P76 alloy V8 engine in 1973.

The 1961 sale to Les Trim led to the factory’s fevered construction from the ground up of Marston’s replacement Lynx #2 which will be the subject of the next episode of this ‘trilogy’.

KERRY SMITH

Photos courtesy the Australian Motor Heritage Foundation

A DIFFERENT COOPER NORTON

A  DIFFERENT COOPER NORTON

Recently, New Zealand motor race historian Milan Fistonic sent me this shot of a Mk9 Cooper Norton, being worked on in the grassy pit area of the long since closed racetrack at Levin, New Zealand.

Captioned as being of Jim Berkett, with Cooper Norton Mk 9-28-55, it is of particular interest to me as it was from Jim that I purchased my JBS Norton in 1971. At the time Jim told me that he also had raced a Cooper as well as the JBS , and had on occasion swapped the Norton engines around. Here’s another period picture of Dick Butters at Levin:

LooseFilings2

The JBS was in the rafters of his plumbing business, the engine was sitting in the back of a VW Kombi van and the remaining parts were spread near and far. The mounting plates on the engine certainly didn’t fit the JBS, however others included in the collection did the job.

This particular single-cam pre-war engine was one of a very small number of race engines which were a fore runner to the venerable double knocker Manx engines which won hundreds of races in both bikes and F3 cars. Indeed most books on Nortons don’t even have information on these small-run engines, however they appear to have been used in 1935 and 1936 works bikes.

In time I had the JBS up and running, and at an event held by the Hawkes Bay Car Club in NZ in 1972 it was spotted by Ron Frost who immediately identified it as ‘’Curley Drydens factory experimental engine’’. Ron (RWA Frost) should have known, as he was not only a motorcycle racer and successful F3 car racer in his native England before settling in NZ, but he introduced many 500 cc F3 cars into the country, including my JBS. He was the driving force behind the construction of the Levin motor race track inside the horse racing facility there, much like his fellow countryman Geoff Sykes did with the Warwick Farm racecourse in Sydney.

It would appear that top Norton tuner of the day, Francis Beart may have worked on this engine given the quote from Iota magazine of March 1951 that he maintained Drydens ‘remarkably fast single cam engine‘, and that FB 444 is punched onto the drive-sidecrankcase.

Fast forward to 2017 and an approach to Derry Greeeklee saw me drive  to Adelaide and snap up a Mk9 Cooper that he had obtained from New Zealand some years earlier, mainly for the 1100 cc JAP engine that was then in it. I was keen to put it back to its original 500 cc F3 form and obtained a Manx engine from Charlie Banyard-Smith in the UK to do this. This Cooper is the exact one that Jim Berkett had owned back in the late 1950s, so now I have not only his old JBS but his Cooper Mk9 as well.

And that’s where the picture gets even more interesting, as sitting in the back of the Cooper in the photo is the single cam ‘’Curley‘’Dryden engine, which is still in the back of the JBS.

I have a copy of the Motor Vehicle registration papers that were used at the time in NZ, even for racing cars. Whilst there’s probably no doubt that Frost imported the Cooper, the first name on this form is Raymond Drew of Wellington. Although not on the entry list, he appears to have competed at the opening meeting at Levin.

Subsequent owners appear to have been Alistair McBeath, then Jim Berkett, Peter Slocombe, Dick Butters, Basil Brimelow, Garth Forsyth,  then maybe it went to Bill Clarke, John Holdsworth – who fitted the twin JAP – Derry Greeneklee and then Garry Simkin.

Garry Cooper Nov 2019 (3)

Fully restored, above, with a new engine , the car has had one short run on the disused airfield at Schofields in western Sydney and had a few ‘bugs‘ sorted out subsequently. When the big bug that is keeping us locked down at the moment is sorted, hopefully it will be out and about on east Australia racetracks.

Garry Simkin

PS Continuing our favourite theme of ‘things still turning up’ it might be mentioned that as opposed to a Mk8 Cooper, which has the engine sitting vertical, a Mk9 has the Norton engine leaning backwards at 15 degrees. To achieve this Cooper cast up special magnesium engine mounts, none of which came with the car. An observant fellow Cooper Mk 9 owner, Brian Simpson, noticed a pair for sale on Ebay and contacted Garry to suggest he bid for the pair. Seems not too many other people out there had these on their shopping list and they duly arrived in his letter box for the grand total of $35.

UP THE CREEK WITHOUT A CIGARETTE PAPER?

There is a better way, says Garry Simkin, who well knows the manipulations needed to time the magneto(s) on an air-cooled car.
He writes:

It seems like forever that I have used a cigarette paper to determine when the points open by way of setting the ignition timing of my magnetos.

As with many things in life, there is a better way. Recently, noted vintage car restorer and Mk 9 Cooper Norton owner Grant Cowie introduced me to the ‘Inductor Magneto Timing Light’.

By connecting the two leads to the magneto, and turning it, this device measures the inductive current, not continuity, to determine the exact of position of the points opening. This causes lights to indicate points opening and closing, but most useful is a rather loud beeping noise when the points open. Having the noise is great when you have your hands busy rotating the magnetos, and are trying to wrestle the cigarette paper while trying to get the drive sprocket onto the taper all the while tightening up the nut. It may be fine if you are an octopus, but it’s a messy and not entirely accurate business.

In his book Tuning for Speed, Phil Irving has mention of a method using a battery, light bulb, leads etc, but this also requires you to remove the centre screw. With the Inductor system no dismantling is required. It’s an all-round fantastic device which was primarily designed for timing aircraft magnetos. You can contact Grant Cowie at his Up The Creek Workshop on (03) 5470 5526 for more details and can check out his workshop and some interesting cars at www.upcreek.com.au

For magneto service Garry is happy to use Chris Zoch at Harrington, NSW, 0424 011 767.

Another cute little device was illustrated nearly a century ago in Motor Cycle magazine and it might be useful to those who like to rebuild their own crankshafts. Most of us with a lathe would put it between centres and then use a dial gauge to check the concentricity of the flywheels, but this little device might have a use if you are one of those people who might find themselves rebuilding their engine at a race meeting as people, including the editor, once did.

GREAT WINTON TURN-OUT

by Steve Denner with photos by Col Roper

A return to (only temporary*) COVID normal brought out a huge entry to the 44th Historic Winton in north-east Victoria on the weekend of 22 and 23 May. A lot of people had been busy in the shed for the last 16 months and the air-cooled owners were no exception. A veritable herd of the little wonders turned up to try out the cunning mods engineered in the darkness of the lock-downs imposed across the country.

Brian Simpson as usual brought out his Mk9 1100 (below) resplendent in fresh paint from chassis upwards, and he was relaxing in the security that an on-board starter gives the air-cooled owner against a stall on the grid or a restart after a “gardening” incident.

Fred Greeneklee brought his Mk6 1100 from South Australia for his “arriver driver”, Peter Fagan (21, below) , who was getting back into a race after a long spell of resting on his laurels. Nevertheless, he was soon on the pace in practice with a 1min 16s and 9th fastest in a big field of no less than 34 Group Lb sports and racing cars.

This correspondent was embarrassed to spin his Mk5 1100 (2 below) on the first corner of the first lap of practice, and being unable to restart was therefore awarded the stone motherless last slot on the grid for the first race.

Greg Snape with the Mk10 BMW 600 (S) put in a handy 1min 17s to put him 12th on the grid, although he was nervous about the future since pre-event servicing had revealed a soft thread when tightening one cylinder stud. Sorry, we don’t have a pic.

Grant Cowie had been doing a lot of work to improve the flexibility of the Manx Norton in his Mk9, while resolving a variety of gearbox issues. These were successful but still left an over-fuelling problem which dogged him for the weekend.

Rod North with the ex Davison Mk5 Vincent (S) elected to run Regularity as he is still sorting out mixture balancing between cylinders on this blown engine. Although he is an experienced speedway rider this was his first venture onto four wheels. Not surprisingly with the Cooper, he says he can’t see much difference! Nevertheless, by the end of the weekend he had destroyed any chance of a Regularity award by punishing his nominated 1:25s nomination with laps in the 1:19s region.

Alan Tidbury with the other Mk5 in Regularity was 5th in the final Regularity on Sunday. This is the car which had an FWA Climax very neatly inserted behind the driver which was coupled to a VW gearbox and transaxle by Bill Pile in 1959. It is altogether a very neat conversion and is perhaps an avenue that Coopers themselves should have explored.

As the weekend wore on, so the major and minor mechanical casualties were either repaired or declared mortal. Brian Simpson’s misfire was sourced back to a loose points mounting stud, but Peter Fagan’s charge ended on Sunday morning when the gear box failed to report for duty with a suspected second gear collapse.  This was a big disappointment after his 3rd place in the Lb race on Saturday, and with a best lap of 1:13.7 in the handicap before a spin and the gearbox expiring.

Your correspondent had an ignition lead disconnect from the distributor instantly turning into a 550cc Cooper, but reported for duty, started and finished in good shape for the final Lb race on Sunday. Unfortunately on the first turn melee found Greg Snape and the Cooper BMW stalled across the track after a tangle with another car. This resulted in a stop and restart to the race and Brian Simpson got everything in the Mk9 together and earned a 4th with a best lap of 1:13.56, winning the Cooper lap time challenge for the weekend.

* The guys were lucky. At the time of publishing, 1 June, the whole of Victoria is undergoing a minimum seven-day COVID lock-down and it may be longer. Great photos, thanks Col!

RE-ENGINED COOPERS:The cooper minx

RE-ENGINED AIR-COOLED COOPERS
The Cooper Minx

Here we have a new theme – with hopefully more to come on the
subject of numerous air-cooled Coopers that had different engines
shoe-horned into the back of them

It wasn’t long after the early air-cooled Coopers started competing in Australia that many owners tired of their often cantankerous engines, JAP engines in particular. Notorious for bad vibrations and reliability issues, many of these were re-purposed with alternative power units, such as small Coventry Climax, Ford, MG, BMC and others. This car shown here with ABC presenter Peter Wherret driving, started with a 1096cc JAP, then had Manx Norton power and has spent the last sixty years with a pushrod Hillman Minx engine.

Imported by John Crouch and originally raced by Queenslander Les Taylor (below), it led the under 1500cc handicap race at the Easter Bathurst meeting in 1951 before clutch problems intervened. The next owner was Mrs Geordie Anderson who had a Manx Norton engine fitted and it became known as the LPS Cooper, LPS being the business name made up from the initials of Ray Lewis, Bill Pitt, and Charlie Swinburne.

Events the car competed in included Whites Hill (Brisbane) hillclimb and it also had a 10th place in the 1954  AGP at Southport, Queensland. The next owner was a B Campbell who competed at Lowood, Qld, in 1957, then it went to motorcycle racer Tony Crick of Wellington, NSW who appears to have done very little running with it before was acquired obtained by Jim McQuire of Sydney. Jim ran it once at Orange, NSW with Alan Tatham doing the driving chores; it was still in Norton form.

Soon after, the Norton was hoisted out, and a 1500cc Hillman Minx engine was shoe-horned into the vacant engine bay, complete with the ubiquitous VW transaxle. A radiator was fitted in the nose with suitable plumbing, a gearshift linkage was made-up to suit the rear entry VW box, engine mods were done and the body work modified to suit. Additional spring leafs were added front and rear to handle the extra weight.

Meetings at Lowood and Strathpine in Queensland, as well as events at Tarrawingee and Hume Weir (Victoria ) plus, of course, various NSW events saw many miles racked up by drivers Peter Wherret (below) and Barry Collerson.

July 1960 saw it compete at the Castlereagh sprint strip where it recorded 16.00 seconds for the standing ¼ mile. Later it ended up with Monty South (who was a previous owner of the Sulman Singer) before going to Peter Cohen who ran in many hillclimbs with the car. He recalls replacing the original Cooper wheels with steel rims but the there is some uncertainty about just when this happened. He also tried reversing front and back wheels but only succeeded in turning too much understeer into too much oversteer. [One of the pictures below, from Amaroo Park, February 1966, has been digitally reversed to simulate them both being taken on left hand corners  – Ed]

In 1967 Peter on-sold it to David Hunt, who lost a wheel at Silverdale hillclimb, a situation that was to repeated by a later owner, the Cooper rear stub axles not being the best engineered of parts. The next owner was Doug Mcleod but we know little of his exploits.

David Kerr of Kurnell, Sydney was a later owner who competed in many historic events with his side-kick Bill Harris assisting. He, also, once returned to the pits at Amaroo on a truck, missing a rear wheel. David sold the car in 1995 and it is still in the hands of John Hermann in its Hillman Minx form, still carrying its 10/54/50 chassis plate.

Garry Simkin

Thanks to Kerry Smith, John Medley and Peter Cohen for their input.

Sports Car World, May 1960 has the following story by Peter Wherret on the fitting of the Hillman engine.

JAP TWIN TIMING SECRETS
… works for singles too

It is Higher School Certificate (HSC) exam time for year 12 high school students in Australia. Poor kids, including the editor’s grandson, have had to cope with a year in which practical work and engagement with teachers –  which could make or break some of them –  has been made very difficult. We wonder how they would cope with the following question from the last year’s Engines – JAP Racing –Maintenance examination as imagined by Steve Denner:

Introduction
A V-twin, 4 stroke engine has the cylinders disposed at 50°. The connecting rods run on a common journal. A half-timing pinion (HTP) has 18 teeth and runs on the end of the mainshaft, i.e. at engine speed, and clockwise viewed from the outside of the timing chest. The HTP drives the 36 tooth cam gear for No.2 cylinder, and this in turn drives the cam gear for No.1 cylinder.

The mainshaft carries a key to locate the HTP, and the HTP has five equally separated keyway options for adjusting the valve timing.

Question
The current valve timing opens the inlet valves at 38 degrees BTDC.
Write the paragraph for the Owner’s Manual which will describe the
procedure for

1. Advancing the valve timing by 4 degrees
2. Retarding the valve timing by 8 degrees.

Steve has reported on last year’s answers and has added some useful drawings. Most candidates worked out that the arrangement of 5 keyways and 18 teeth is essentially a vernier coupling. That is, there are 5×18 (90) different positions that the half time pinion can be engaged with the cam gear. Dividing 360° by 90 means each position offers a 4° degree variation.

It is essential to start from the existing and known valve timing by marking the current engagement of pinion and cam teeth, and also the currently utilized keyway in the pinion.

STEP 1 requires the pinion to be disengaged from the crank with the cam gears held in position, and the crank rotated anti-clockwise and
re-engaged in a new key position as dictated by the required degrees of advance or retard (see table below).

STEP 2 requires both the crank and pinion to be rotated clockwise by the number of teeth indicated in the table, and the pinion to be
re-engaged with the cam gear teeth that were marked at the outset.

Condensed into a tabular form it looks as follows. The degree of advance or retard achieved is the difference between Columns 1 and 5.

The first response was from Mark Burns who eats lots of fish, does The Times crossword before breakfast, and consequently has a brain the size of a small planet. He also produced the drawings to support his solution. Planning permission has been applied for and many thanks, Mark.

Curiously no response was forthcoming from any Morgan Three-wheeler owners. Perhaps a cold chisel and 2lb lump hammer is all that is required to keep them running?

The author thanks all participants and thanks them collectively for saving him the trouble of exercising his own strained grey matter, and hours of random and pointless meddling on the workshop bench.

Stephen Denner

The editor is also most grateful, being about to re-time the Walton JAP engine that shed some cam gear teeth just in time not to make the Collingrove hillclimb a year ago.

WHATEVER HAPPENED TO…?

Here’s something new to add to our occasional ‘Still things turn up’ theme. Let’s call it, ‘Whatever happened to …’ which is especially relevant to the Coopers that came to Australia, New Zealand and other places such in Asia and Africa and then became something else, often with four cylinders.

The excitement of having a brand new Cooper from England may well have soon rubbed off as local specials could sometimes show a clean pair of heels to Surbiton’s best. If you had a ‘big-twin’ JAP in it rather than a ‘500’, the chances were that its unreliability would get you down.

An obvious solution was to put something else in it and so the Loose Fillings team thought we should have look at things that people did to Coopers engine-wise. The first candidate has been described for us by Andrew Halliday who writes as follows:

Built in 1949 by the Cooper Car Company at Surbiton, Surrey England, car 10-26-49 was powered by a 996cc JAP dry-sump 8/80 V-twin engine and was painted red. The car is the oldest survivor of the first batch of Coopers which was imported to Australia by Keith Martin, the original Australian Cooper agent.  The cars arrived in Melbourne on 25 January 1950 and this one, coloured red, was purchased by Jack Saywell who had raced a monoposto Alfa Romeo before World War 2.

It was the second Cooper to race in Australia, and it made its first race appearance at the Easter car races at Bathurst in 1950 as number 4. It was timed at 190 km/h (118.4 mph) through the flying quarter mile down Conrod Straight.  In the under 1500 cc, 25 mile race, the car finished 5th, winning the handicap with a fastest lap of 3 minutes 10 seconds.

In the October meeting at Bathurst (above) it finished 4th in the 12 lap, 50 mile under 1500cc race, with the fastest lap of 3 minutes 13 seconds and fastest time. At the Easter 1951 Bathurst meeting it became the first car to lap the circuit in 3 minutes; in unofficial practice Saywell crashed into to the fence near Quarry Bend and during the race the car broke a countershaft sprocket.

The 1952 April Bathurst meeting was held as the 17th Australian Grand Prix and the car finished 16th. It raced at Ballarat, Parramatta Park and Mt Druitt winning a few races. The car was maintained at Jack Zeidler’s workshop in Leichardt, Sydney, and the engine was maintained by well-known motorcycle racer Don Bain.  With business commitments to deal with, Jack Saywell parked the Cooper at the end off 1952 and it sat around for five years.

In 1957, Bill Reynolds, a well-known speedcar driver, motorcycle racer and announcer at the Sydney Sportsground Speedway, purchased the car.  At the Easter Bathurst meeting, during the Bathurst 100 of 26 laps, the car caught fire as it exited Forrest’s Elbow and returned to the pits with flames shooting to the sky.  It was found that a float bowl had come loose, spraying fuel onto the exhaust pipes.

Bill raced the car at Mt Druitt (above), winning two scratch races and the NSW Sprint Championship, and he won the 501cc to 1100cc class at Silverdale hillclimb. Doug Chivas raced the car for Bill Reynolds at Mt Druitt, winning an under 1500cc scratch race.

In February 1958 Jack Myers purchased the car for hillclimbing, removing the JAP 8/80 and replaced it with a pair of 650cc twin Triumph twins which were later supercharged (below) .  One of the engines ran in reverse direction and chains served all three drives – primary, final drive and blower.  The final drive was through a Cooper ZF differential. The gearbox was from a 1938 Norton motorcycle.

The car was capable of 120 mph (200 kph) and a standing ¼ mile in 13 seconds and became known as the Tangerine Tornado. Ken Waggott helped engineer the car and would drive it too, only to break crankshafts at Gnoo Blas (Orange), Foley’s Hill at (Mona Vale) and Fishermens Bend (Melbourne ).  Eventually Jack Myers solved the problem at his Maroubra workshop.

Jack’s first outing in the car was at Foley’s Hill. Never having driven the car, he broke the record in practice and in competition bettered his time by 1½ seconds.  His next meeting was at Huntley’s Hill near Wollongong, breaking the course record. This would be the last time the car ran with natural aspiration, it then having a supercharger off a Spitfire fitted.

While on his way to the Bathurst hillclimb, Jack called into Marsden Park airstrip to do some testing and put a hole in a crankcase. He missed practice but knocked ½ a second off the record on his second run. He also won the NSW Hillclimb series smashing all four outright records in all competition events.

In 1960 Jack Myers again won the NSW Hillclimb Championship in the car. He then replaced the Cooper with a chassis built by Ron Tauranac, removing the two Triumph 650cc engines from the Cooper and putting them into the Ralt chassis.  Jack would lose his life in the Ralt at Katoomba’s Catalina Park on 21 January 1962.  In 1961 Peter Williamson had purchased the Cooper using it at Silverdale Hillclimb powered by an Ariel engine and finished third in 50.37 seconds.

The car was next purchased by Bob Joass who rescued it from decay. It was later owned by Peter McCleay until 1976 when Tony Caldersmith acquired it.  In 1990 the car was issued with CAMS first ever Certificate of Description and was displayed in a Parramatta bookshop shop window in Church St in 1993. In 1995 Matt Segafredo, a Formula Ford racer, purchased the car as he liked the look of it and it sat in his lounge room for years until Andrew and David Halliday acquired it for historic racing.

Stirling Was Great

As is well known, Stirling Moss’ first motorsport event was at Shelsley Walsh hillclimb in a Cooper 500. In 1948, and still today, Shelsley is one of the world’s great motorsport venues, so what better place to start such a career?

The Midland Automobile Club  has always run the hill and recently published in its MAC News a fine tribute to Stirling  with an emphasis on his ‘air-cooled years’. With the club’s  kind permission, here it is complete with his 1948 entry from its archives:

Moss obit_Page_1

Moss obit_Page_1AMoss obit_Page_2-001

Moss obit_Page_2

BUMBLE HILL

Scroll down for earlier stories
  • The Mystery of the Seized Cylinder
  • Magnetos – a care free alternative
  • Art Seniors’ very fast JAP
  • A short history of JAP speedway engines
  • With and without glory
  • Skirrow progress too slow!
  • Starting trouble?
  • Great Cooper pics on-line

GREAT DAY AT BUMBLE HILL in 1960

by Garry Simkin

In the Yarramalong Valley, inland from Gosford NSW, near the small village of the same name, is a stunning piece of road which seems ideally suited to make a decent long hillclimb. Steep in places, windy and newly black-topped, I have driven over it on many occasions of late and it seems to be an ideal venue.

In a chance conversation with John Wright of Gosford regarding the road, he told me that there were in fact a few hillclimbs held there in years gone by. On 11 September 2020 it will be 60 years since the Central Coast Car Club held a round of the New South Wales Hillclimb Championship on the hill, and not only was John there, but he had some fantastic photos to prove it.

Fastest time of the day was taken by Jack Myers in his WM Cooper, and the first of the air-cooled cars was 3rd quickest, Geoff McClelland in his self built MacVincent.

 

Winner of up to 750 cc racing car class was Neal Simpson driving the Aquilla, a swing axle device that John describes as ‘an evil handling car’.

 

Geoff Surtees was second in the class in his Surtees JAP – see more on this car in Loose Fillings #32 at www.loosefillings.com/back-issues This car is shown in front of the Chrysler, with no number on it.

 

The MacVincent, number 67 has Loose Fillings’ founding editor Graham Howard to the right in the front-on shot (below), and with his back to the camera in the rear-on shot (earlier).

 

Car 18 is the Ewing with Harley Davidson bottom end and ES2 Norton heads. There is more on this car in Loose Fillings #14 and an obituary of Ron in #7.

 

Cars 30 and 31 appear to be Ralts, and we do know that Alan Hindes was competing in one on this occasion.

 

Thanks to John Wright for the photos and Brian Lear and John Medley for help with the details.

Here are a few more shots which give an idea of the range of cars and people then in action starting with Tom Sulman’s  Maserati 

 

Doug Kelly’s Cooper Climax type 41

 

…and don’t you love the Mk2 Zephyr ute –  what happened to them all – or weren’t there that many –  John Bisset’s Buckle is behind it

 

The Mystery of the Seized Cylinder

Scroll down for earlier stories
  • Magnetos – a care free alternative
  • Art Seniors’ very fast JAP
  • A short history of JAP speedway engines
  • With and without glory
  • Skirrow progress too slow!
  • Starting trouble?
  • Great Cooper pics on-line

MYSTERY of the SEIZED cylinder

Most enthusiasts are familiar with the 8/80 V-twin JAP engine. It is essentially two of the famous 500 speedway JAP heads and cylinders bolted to a common crankcase to give 1000ccs of brute power. Made by the English company JA Prestwich, variants of their V-twin engines went into countless Morgans, Brough Superior motorcycles, speedway sidecars, and early Cooper racing cars.

Around 1990 I acquired a 1955 Mk9 Cooper fitted with an 8/80 JAP. It was an exciting car to drive with an excellent power to weight ratio, and went like a jet. For about a lap! Then, as soon as the engine reached operating temperature and ran on full throttle for a few seconds, the front piston would either seize and or melt. This was a real puzzle, because with identical carburettor and ignition settings the rear cylinder showed no signs of distress.

The obvious cure seemed to be to guarantee adequate fuel flow to the front carburettor, and fit larger and larger main and needle jets. All this achieved was to upset the carburration and allowed the engine to run a little further up the road on full throttle before the front piston failed again. Similar experiments with ignition timing, various grades and makes of sparking plugs, and substantial air scoops directing air onto the front cylinder, all failed to achieve a result. Over many visits to the race track for private practice, the engine just kept eating pistons and plugs on the front cylinder. Nothing I did made the car driveable flat out. Something was basically wrong. But what?

I started to ask around. One old retired sidecar speedway rider with a long memory knew what I was talking about straight away. He’d had the same problem with the front cylinder on his 8/80 sidecar outfit running hot, but not as bad as mine because his race lengths were only four laps, and his motor was exposed to the breezes. His cure was to have his sidecar passenger pump an extra shot of oil onto the thrust face of the front cylinder when he had a spare moment between corners! This idea had some merit because the rear cylinder of a V-twin gets most of the oil flung out of the big end and off the flywheels, and the front cylinder gets very little. However trials in this direction made no real difference to my engine.

Then I read something in an old 1954 Motor Cycle magazine that sounded interesting.

The article, (see below) by well-respected rider and journalist Vic Willoughby, was the story of a similar V-twin JAP used for record breaking at Brooklands and ridden by a Ted ‘Barry’ Baragwanath. I quote,……”The front carburettor jet was about 2 sizes larger than the rear to combat an INEXPLICABLE tendency to overheating of the front cylinder.” I kept reading and found more….”Early tests at Brooklands revealed  a pronounced tendency for the front cylinder to overheat… so much so that it was impossible to complete a FULL LAP ON FULL THROTTLE.”

CCI15052020

That was exactly my experience, so I was not alone! But what to do? I was tempted to say, “OK. Just let’s use the car for hillclimbs and forget about circuit racing. The head is cast iron, has virtually no cooling fins, and is only meant for the speedway anyhow.”

Now, from the 1920s and even earlier, JAP made thousands of engines for all sorts of applications and one hesitates to question the design of such a well-known manufacturer, but after all the work we’d done, something had to be basically wrong somewhere. So the question remained unanswered. Why did only the front cylinder overheat when both cylinders were the same? But were they…… the same?

In desperation both front and rear cylinder heads were removed, stripped to the bare castings, and examined side by side. They were identical…. EXCEPT FOR ONE THING!

What follows needs a brief explanation. When we look at a standard 500 speedway JAP engine’s cylinder head, we find it has the carburettor and exhaust pipe ports located on the right hand side of the head, (like the typical English BSA or AJS.) This 500 speedway head will bolt straight on the rear cylinder of the 50 degree V twin. However if we try to bolt a 500 head on the front cylinder of the twin, we find the front carburettor pokes into the rear cylinder’s exhaust pipe. So Mr. JAP got over that problem by using front heads for the twins identical to the rear heads, but with THE INLET STUB FROM THE RIGHT SIDE TO THE LEFT. Now the front carb pokes out on the left side of the engine, well out of the way of the rear exhaust pipe.

IMG_6236

‘Barry’ with ‘blower’ – not the usual view

But what does this have to do with our overheating problem? The answer is everything, because when we take a quick look down the inlet ports of both front and rear cylinder heads with the valves removed, something is obviously different! It’s all to do with the location of the spark plugs! On the rear cool running head the plug is clearly visible, and the electrodes are in the direct path of the incoming cooling air and fuel. But looking down the inlet port of the hot running front head, the PLUG is hidden around the corner and NOT VISIBLE at all, and therefore does NOT enjoy the full blast of cooling air and fuel on its electrodes on every intake stroke.

Consequently, on 14:1 compression on full throttle, and with skimpy finning on a cast iron head, it was reasonable to assume that it would not take long for the electrode of the hardest plug in the range to become incandescent, pre-ignite the charge, and destroy one piston after another.

So, working on this theory, we drilled and tapped the front head to 14mm, and transferred the spark plug to the opposite side of the combustion chamber where it would be directly in the path of the incoming charge, just like the rear head. The results were immediate!

Now with sensible jetting, the engine will hold full throttle down the long straight at Mallala, and do six flat out 1.25 laps before something else breaks … but that’s another story!

Chas McGurk

Editor’s Note: As best we can work it out, about 1933-4 JAPs moved the inlet port on the speedway engine from the left (as shown in the drawing  below)

Image (435)11237

to the right hand side, as described by Chas. The original head design then seems to have been used on the front cylinder of the 8/80 which went into limited production for the Skirrow in 1936. This same engine, but with the crankcase extended to provide a sump, was used in the 1949 Cooper twins and was followed by what JAP called the ‘Mk1 ’in 1950 with aluminium heads and barrels.

 

 

 

 

MAGNETOS – A CARE FREE ALTERNATIVE

by Steve Denner

Many moons ago Chas McGurk confided to Demon Tweaks that it was possible to convert the V-twin JAP to a simple coil and distributor (Kettering) system by mounting and driving a distributor in place of one of the magnetos.

In one such conversion Chas had crept up on an unsuspecting Vincent and requisitioned its 50 degree distributor cam which was then “cut and shut” into an early Lucas distributor. This surgery required bits of different distributor shafts to be welded together to provide a taper for the JAP bevel gear at one end and a home for the Vincent cam at the other. Shaft alignment under these circumstances is difficult to achieve. An alternative has been tried as described here.

For myself, the sound advice from Andrew Makin at Performance Ignition Services in Melbourne was to start with a Bosch distributor ex VW, and “Made in Australia”. The reason? He can still get almost any spare required to provide continuing service of the instrument. The vacuum advance is removed and the rotating plate is locked to the base plate with a BA screw. Here are the major steps:

First, make new bracket which mounts the distributor horizontally on the left hand magneto platform so that the drive shaft is at the correct height to engage with the bevel drive from the timing chest. Second, modify and fit the JAP bevel gear on the distributor drive shaft. Third, make and fit a suitable cam for a 50 deg. twin instead of an in-line four VW. Fourth, modify the distributor rotor so it can deliver two unequally spaced sparks through the existing four cylinder distributor cap.

1. Distributor mounting bracket.
This may be either fabricated from mild steel or cast from aluminium to suit the platform mounting. I chose the latter (because I am a lousy welder). The shaft centre height is 45mm above the platform, and the distributor is 1.062” diameter where it is clamped. See below for machining the 45mm centre height of the distributor and below that for distributor mounted in the bracket:

IMG_3742

IMG_3743

2. Drive shaft bevel gear.
The distributor in its VW life is driven by a skew gear which is a parallel fit on the distributor shaft and pinned in place. The standard JAP bevel gear has a taper seat with no keyway. The choice is therefore to either grind out the taper to fit the shaft or grind a taper on the distributor shaft to fit the gear. It was much easier to have the gear ground to fit the shaft (0.491”) and it can then be drilled and secured with a roll pin to achieve (say) 0.005” end float. It should be a precise but not a press fit on the shaft which would make it difficult to dismantle for servicing; the pin will take all necessary drive load.

3. Cam for points
The problem of making an accurate cam is simplified by recognizing that the only critical point is when the points open and a spark is generated. All other points in the cycle can be “more or less”. The dwell time when the points are closed should be not less than 30 deg but could be a lot more, with the only disadvantage being a heavier drain on the battery. The points gap for the rest of the cycle should not be less than .015”.

The Bosch cam is removed by off-hand grinding the hard casing, after which the rotor shaft can be turned accurately with a carbide tip to 15mm dia. A new cam ring can then be machined (below) and fitted to the rotor shaft. The ring has two pairs of flats accurately milled, using a rotary table or dividing head, at 0 deg and 155 deg. The second flat is cut 20 deg ahead of the first to ensure that the points are closed for about 35-40 degree of arc. Importantly, this cut on the leading end of the first cut does not affect the critical point where the contacts open.

IMG_3737(5)Cutting flats for the new cam-ring

The cam rotates clockwise viewed from the distributor cap end, as shown below. Therefore the points will open at the LH (trailing) end of the flats. Providing that nothing is done to remove metal from this critical contact point you now have an accurate ignition cam for a 50 deg twin.

Distrib cam drwngMachining details for the pairs of flats

I made the new ring 20mm diameter, which is slightly larger than the diameter of the Bosch cam. Too big a diameter would increase the rubbing speed of the fibre heel of the points. The adjusting slot in the points holder will need to be filed longer to allow correct gap setting with this increased diameter.

In practice it is sensible to lightly stone the edge where the flats and outer diameter of the ring intersect to make life easier for the fibre heel of the contact arm.

IMG_3741The new cam ring  machined and fitted to the rotor shaft.

The new cam ring is made from 4140 steel because it can be nitride hardened, which will be done at a low enough temperature to avoid any distortion. Aim for a light push fit on the shaft so that you can Loctite it in position and this will be enough to prevent it slipping under the friction of the fibre heel. The cam will need to be indexed to the rotor arm so that the rotor is passing a post in the distributor cap as the points open. The rotor is modified as described below to cope with the unequal spacing between cylinder ignition.

IMG_37394. Rotor arm.
The standard Bosch rotor arm is retained but modified to extend the arc of the arm (right). This is necessary because the terminals in the cap are spaced for 4 cylinders at 90 rotor degree firing intervals. We are using only two of the (opposing) terminals but the spark will be delivered at 155 and 360 degrees of rotor arc. This is done by soldering a prepared brass segment to the existing arm, but be careful that the extended arm does not foul the terminals in the cap and that the HT spark is not asked to jump Sydney Harbour. Bits of plasticine or BlueTac could serve as a witness to check this. Finally assemble the cam so that the rotor arm is abreast of a contact in the cap at both of the opening points on the cam.

The mechanical advance system is retained and to check the ignition at the desired full advance position grip the rotor arm and rotate clockwise so that the advance weights come up against their stop. Ignition advance is adjusted by rotating the distributor body in the cradle and clamping, which is substantially easier and more accurate than trying to position the bevel gear on the taper and tighten  it up after disengaging the magneto.

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ART SENIORS’ VERY FAST JAP

Continuing our occasional theme of Still Things Turn Up, we have news of the revival of a JAP-engined motorcycle which was prepared and ridden by one of Australia’s most controversial motorcycle characters. On it, he set three outright Australian land speed records and holds the lap record at the Vale circuit near Bathurst.

Art Senior is most famous for extracting explosive power from humble Ariels but he first came to prominence in the early ’30s on a self-tuned but wickedly quick flat-tank AJS. On this he set an all-comers Australian quarter-mile speed record as well as winning the 1934 Junior GP in record time at Bathurst. He also won the 1935 Senior GP at Phillip Island, again on an AJS and most likely the same machine.

In late 1934, New South Wales OK Supreme agent Stan Ellis acquired a retired factory racer (see above) to help publicize and sell OKs. The bike had been campaigned in England throughout the 1934 season, including the Senior TT at the Isle of Man. Ellis offered to pay Senior’s expenses, a generous retainer and all winnings if he would prepare and ride it in major race and sprint events.

Eventually, on 27 November 1935 Senior made a successful attack on the Australian flying quarter-mile record wresting it from Rudge-mounted Wal Hawtrey. Senior’s outward run was 111.11mph and the return 112.23mph, for a mean speed of 111.67mph. In June 1936, Norton-mounted Leo Tobin added 8.33mph to Senior’s record for a mean speed of 120mph and Australian records in the 500, 750 & 1,000cc classes.

It was thought that this figure might stand for some time but within a couple of months, Senior had smashed both it and the 130mph mark. A newspaper reported, ‘On Wednesday August 27th, in very adverse conditions on a course close to Sydney (Hume Highway near Liverpool), Arthur Senior, the well-known Sydney racing cyclist, attained the highest speed on the road ever recorded by a motor cyclist in Australia – 130.434mph. His average speed of 123.288mph for a two-way run is accepted as an Australian record in the 500, 750 and 1,000cc classes. Senior was astride an ex-works OK Supreme on which he had previously established the record in late 1935 before it was broken by Mr Leo Tobin some eight months later’.

For the first record attempt, the bike had been stripped but, for the second (see below), Senior and Ellis decided to streamline the OK. Their inspiration was the supercharged Brough-JAP streamliner (known as Leaping Lena) that had set a world sidecar speed record when piloted by Australian Alan Bruce. Senior, ever reluctant to farm work out, set about fabricating the panels himself.

An aluminium wedge enclosed the crankcases, gearbox and clutch. The front down-tube and fork blades were sheathed in the same material. An elongated tail cone, which also covered the top of the disked rear wheel, was shaped to allow his backside to slide inside. And a new petrol tank enabled Senior to squat even lower. Lastly, a handlebar fairing, designed to deflect wind over his reverse beaked helmet, was made.

Art Senior on the Hume Highway on a very wet record day, and below, outside the Stan Ellis showroom

The TT wheels, with their large brakes, were replaced by weight-saving unbraked front and lightly-braked rear items. To minimize rolling resistance, the tyres were the thinnest imaginable. While it lacked Leaping Lena’s elegance, Senior’s Ned Kelly-esque hotchpotch proved surprisingly effective. He later remarked ‘The most difficult part about the streamlining was finding somewhere to attach it’ (the writer has noticed that some lugs have been crudely altered and wondered why. Clearly this was done to aid mounting the fairing).

But hang on – 130mph! That’s a 15% speed increase on the original bike. Impossible! Without access to wind tunnels, streamlining design in the day left a lot to be desired and could not possibly account for all that improvement. Something else was clearly at play.

Unbeknown to those outside the inner sanctum, Stan Ellis had recently taken delivery of a new JAP JOR racing engine (JOR V/46508/S): a pukka 1935 big fin, twin carb, twin spark job used exclusively by HRD at the TT. It shared the same bottom-end as the ‘34 unit so slotted straight in. He fitted a high-compression piston to run on alcohol and enlarged the inlet ports from 7/8” to 1-3/32”. The ports are splayed at 22.5˚ with 7˚ of downdraft and are fed by two right-handed carbs (handed pairs were not made before the war). This engine type had only ever been used in anger once: in the 1935 Isle of Man Senior TT where, in stark contrast to the previous year’s lightly-finned, single-carb units, it proved both fast and reliable.

As the fairing hid the new motor from inquisitive eyes, the remarkable speed increase was put down to a combination of Senior’s freakish ability to conjure yet more grunt from clapped out junk allied with the wind scything properties of his crudely fashioned fairing. Art’s and Stan’s secret was well kept. The record-breaking bike was soon put on display at Stan Ellis Motorcycles Goulburn Street premises. A massive placard proudly proclaimed it as ‘the fastest motorcycle in Australia’. It proved a huge draw card and orders flooded in.

With OK sales soaring on the back of Senior’s records, Ellis offered Senior his own OK Supreme agency which duly opened on 1 June 1937. Senior should have been over the moon but something was gnawing away inside him. Shortly after a club event on June 13 (his last on the OK), Senior demanded Ellis gift him the record-breaker as was the tradition following a successful record attempt. Ellis rejected Senior’s claim as he had not only financed the entire campaign but this was not part of their deal.

Senior’s decibel-rich dummy spit not only kayoed their lucrative two-year partnership but also his own 2 week old OK Supreme agency. However, Australia’s fastest man wasn’t out of the saddle for long. Ariel’s Eric Moore gave him a new Red Hunter to race and sprint. It turned out to be a very lucky move as Senior’s record-breaking resumed and Ariel survived the war.

With the war killing off both motorcycle racing and OK Supreme production, the bike lost its hero status and its purpose. Now little more than a curio, Ellis moved it on and it was thrashed and trashed. I can only assume that the person(s) responsible for this vandalism was oblivious to its great deeds. Sometime in the early ‘fifties, it sold as a flogged-out ex-racer with no special history. While the new owner, who sold it to the writer, never got it running, he did arrest its decay. And so, despite the abuse and despite languishing unrecognized and largely unloved in a western Sydney shed for nearly seven decades, it survived.

Over time, many important components such as the TT-spec Webb forks, drop-forged Harwil front wheel, Bowden racing levers, bespoke oil tank and Amal TT carbs had disappeared. The condition of the remainder varies greatly. The frame has several broken lugs and more twists and turns than the Nurburgring. The TT petrol tank and Harwil 8” rear brake have clearly had a hard life but the priceless mechanicals: the Burman AR racing gearbox and bronze head twin carb JOR engine are surprisingly sound. There remains enough of the original for an authentic resurrection.

The bike as it is today

For practical reasons, the bike will be returned as closely as possible to its 1937 Bathurst lap record trim. A frame jig has been fabricated and a set of double-damped TT Webb forks and Hunter Bros front wheel (a favourite of Art’s) found. Bronze 7/8” Amal 15TTs are proving elusive. Period racing Bowdens will have to suffice for the moment. A new oil tank, primary guard and exhaust pipe will need to be made.

By and large, progress is glacial, but the bike, bless it, survives.

Anon

A SHORT HISTORY OF JAP
SPEEDWAY ENGINES

by Terry Wright

The following is another experiment in posting more detailed information online. Not having worked out how to display a pdf file, the following is in the form of images and some of the detail may have been lost. If you zoom to 200 or 300% you should be able to read the text but the detail of the drawings will still be hard to read.

Its an analysis of surviving JAP engine drawings and other information which attempts to create a history of the earlier speedway engine. Corrections and comments are most welcome either here or on the JAP Engines Facebook group.

This is very much a work in progress. To download the full pdf of 9 pages click here JAP info models etc See also JAP DRAWINGS SURFACE

With and Without Glory

Terry Wright looks at what is needed to complete his
history of the big-twin Cooper.

POWER WITH GLORY: Hillclimbing the Big-Twin Cooper has long been the provisional title of the intended sequel to the Loose Fillings history of the big-twin Cooper and its antecedents to 1950 or so. It has been planned that it would cover the great hillclimb years of 1951-1961, when the Cooper was absolutely supreme in the UK as well as many parts of the Commonwealth and the Empire.

When all is ready it could take a couple of years to distill the research, write the text, select the pictures, lay out the pages, collate the citations, caption the photographs, prepare the index, get it printed and reviewed … and manage the sales whereby I should just about break even on the printing costs. But time is running out and if I can’t get some input from the UK it’s not going to happen.

While the main story is clear and easy enough to write, there are too many little ‘back-stories’ and details unresolved. As well as the historical narrative, I am proposing to catalogue all the period big-twins although without trying to document their provenance beyond 1961. In my view the book needs this catalogue and the catalogue can’t be done without more definitive research. That means ‘boots on the ground’ and that isn’t possible for me at the moment.

The Australian, New Zealand, Asian and African cars are fairly well resolved because they have been in tightly knit motorsport communities where the provenance of the surviving cars is generally well known right up to today. But many of the British cars are all-over the place as far as their history is concerned. There are too many mysteries and inaccuracies in the folklore which is often all there is to go on.

For example reliable information is needed on the following:

The Ken Wharton championship winning lightweight Mk4 was sold to Scandinavia less engine by Bryan Eccles around 1960. What has become of it? Here it is in Bryan’s hands …

Rivers Fletcher had a Mk8 c1958 – what became of it and who had it before him … ?

The Bertie Bradnack’s onetime twin rear-wheeled Mk7-L3-53 most recently driven by Doc and Tom Willoughby was certainly driven on at least one occasion by Tony Marsh at Rest and be Thankful – why – was he thinking of buying it ? Here it is with Bertie at Brighton …

And what happened to MK7-L1-53 and Mk7-L2-1953 of which I have found no trace. Was one of them the Peter Bell owned car which Michael Christie drove from 1953 and then Ken Wharton drove in his last year before he was killed … ?

Was another the Mk7 (possibly) that Les Leston raced in 1953 when everyone else had given more or less given up racing the twin? And was this a factory car run with full Cooper support and if so what was the objective … ?

What became of the ex Peter Hughes car that David Roscoe sold to Jimmy de Villiers in Rhodesia in 1958 and which may have been rebodied (below) .

Almost certainly it is this car in the Rhodesia copper belt …

What happened to Mk5-L3-51 ordered by Harry Schell according to the records published by Doug Nye, but which I am sure he never raced. Did someone else get the car and if so who? Here is the 1950 Mk4 twin

Betty Haigh had 10-38-50 – what became of it? Indeed what became of most of the early Mk3 and Mk4 twins including those of Spike Rhiando, Syd Logan, George Abecassis, John Cooper, Bill Aston, George Hartwell, Bill Whit house, Pat Fergusson, Eric Brandon, Ray Merrick Michael Christie, Ken Wharton (his first 1950 car) and various others?

These are only some of the questions needing answers so any input would be much appreciated. Most importantly I would be grateful for the sight of ANY 1951-1961 period twin photos of ANY quality. In many case such photos are the only surviving primary evidence of who had what car when and where.

Terry Wright

Skirrow Progress Too Slow!

SKIRROW PROGRESS TOO SLOW!

Some years ago I bought a ‘Skirrow Special’ on eBay, of all places. The Skirrow went into limited production in 1936 and was a development of a prototype that Harry Skirrow had built for Belle Vue, Manchester speedway. It was all part of a plan to start up speedway car racing, which was a raging success in the United States, in England.

Belle Vue decided to build their own cars so Harry started a company called Skirrow Special Cars Ltd to build his. Car Speedway Ltd was set up to run the business side of things and there was a National Association of Speedway Car Racing Circuits that licensed drivers in 1938 and 1939. The photo below shows one of the Belle Vue Elto-engined cars ahead of a Skirrow-JAP at Coventry speedway some time in 1938 or 1939. When the war started, racing  came to a stop for the duration.

Skirrowracing

The photo below shows a brand new car at London’s Lea Bridge speedway where they were built for Harry Skirrow:

Mackereth

Post-war, about a dozen or so of the  JAP 8/80 V-twin­ engined cars were bought up and kept in Northamptonshire by Dave Hughes who founded the Brafield speedway  in 1949. He took the cars to speedway tracks all over the country, organized races and did what he could to revive midget car speedway racing.

Some Skirrows were still racing in 1962 but cannot have lasted much longer. Sometime in the 1960s, one of the most successful of the pre-war midget drivers, Les White, bought one of Hughes’ cars. lt was just ‘for old time’s sake’ said his son Malcolm who did a ‘light restoration’ on it and demonstrated it from time to time at a local speedway.

When Les retired from the garage business he sold everything up and the car went to America, eventually to a private collection in Florida. From there it was sold to Canada, and then I bought it without an engine and shipped it to Sydney with the aim of restoring it and running it in Vintage Speedcar Association events. Here is the car as it arrived,

SkirrowAsBought

The chassis has two pairs of BSA FWD springing and drive mechanisms, one at the front and one at the back as can be seen in the following drawing:

SkirrowChassis

The rear wheels are obviously fixed direction-wise and both ends are without dampers. The front uses a BSA steering box and column with a Bluemels sprung steering wheel.  A double sprocket on the front-mounted engine drives forward and rearward Rudge clutch assemblies which are on counter-shafts running in cast aluminium mounting cases. Exactly as on a speedway bike, a final drive sprocket is fixed to each clutch and drives a shaft on the ends of which are flexible joints and all the other BSA bits and pieces . The following video shows the chassis and the transmission after the body was removed:

The whole of the chassis and running gear was stripped to bare metal and reassembled with repairs and replacements such as the flexible drive couplings using the invaluable assistance of the BSA FWD club’s spares scheme. The sprockets were replaced and a new rear drive-shaft was the only significant part that needed to be custom-made.

I was prepared to make an engine more or less from scratch but I was lucky to acquire a post-war  8/80 JAP and Greg Summerton has made a new crankshaft and reconditioned the bottom end. The cylinders need to be relined and a new timing cover machined to accommodate the prewar total-loss Pilgrim pump. Cylinder heads and rocker gear need a service of course and there are brand new Mahle pistons andTerrys valve-springs in boxes as well as new valves. There are Amal type 27 carburettors with twin float-bowls. but no magnetos.

Rudge speedway countershaft units and clutches seem to be like gold but I found two sets of these to replace the ill-fitting Norton units. The very stylish body, which is mainly several heavy pieces of welded sheet metal sitting directly on the chassis, has been extensively reconditioned with some new panels and it is now ready for final finishing. Here it is at the moment:

20200302_142058

20200302_142122

Nobody knows how many Skirrows were made but I have seen a reference to Harry Skirrow saying there were just 17. Several were reportedly destroyed by bombing in the war, two ended-up in Australia but have since been lost and, allowing for a few to be scrapped, that would line-up with the dozen or so that Dave Hughes had.

There seem to be just three complete Skirrows surviving including this one. Bugatti expert Ivan Dutton has one which he bought at auction about ten years ago; it is complete and running. He also has a real treasure in the substantial remains of demon-driver Spike Rhiando’s Skirrow as well as one of the Elto-engined cars built for Belle Vue. It was Spike Rhiando’s spare engine for his Skirrow that was part of a deal for John Cooper to build a long chassis car with the 8/80 JAP at the rear. Spike first raced this in the Isle of Man in 1948.

I wrote a while ago that work on the Skirrow had stopped while several other projects – a book and another car – were finished off. That work seems to be  everlasting, so I want the Skirrow  to be taken over by somebody else. I bought it out of curiosity and dug up a lot of  history some of which was used in my book Power Without Glory.  The Skirrow was a pioneering series-production single-seat racing car with strong motorcycle connections. Significantly, it was the reason the 8/80 JAP, as developed by Eric Fernihough for his world’s motorcycle record efforts, went into limited production.

It’s a sweet little car and if you would like full details of what has been done, and still needs to be done, with a view to making an offer for it over $A30,000, or about £15,000, please get in touch.

Terry Wright

tsrwright@gmail.com

There is another Loose Fillings article about early English speedway car racing at  https://loosefillings.com/2015/12/13/bugattis-did-it-too