Klamfoth restoration part #1 - a twin amongst the singles, a swinger amongst the rigids

Previously  I wrote about my involvement in Project Daytona that involved a team of researchers in Florida and Scotland restoring a 1954 BSA Daytona Gold Star and Shooting Start in-time for the 2004 50th anniversary of BSA’s historic first five places sweep-up in the 1954 Daytona 200 mile race.

The most obvious and defining characteristic of these bikes was that they were rigid framed, at a time when BSA had just introduced swing-arm frames. The research element alone for this project took years and was difficult enough at time to feel more like archaeologiy than restoration but we managed to tie-up most of the loose ends, or enough to make us happy enough to parade the bikes in 2004.

We also decided to build a replica (or a restoration if we ever find more original parts) of Dick Klamfoth’s 2nd place bike but if the specification of the rigid bikes had been a big puzzle to solve, then Dick’s bike was an even bigger one because it alone amongst BSA’s works team was fitted with a swing arm. 

We had only a few poor photos to work from but reckoned that an incorrectly captioned photo in the Bert Hopwood book ‘Whatever Happened to the British Motorcycle Industry? was the same bike or at least the bike in prototype form.  This blog entry explains why we think so.

Obviously, the first thing we did was ask Dick -  but he wasn’t sure.  Dick remembered that BSA thought that amongst the riders he would be best suited for a swing arm because he had ridden a plunger Manx Norton in the previous 2 Daytonas until a regulation change made them ineligible. Dick also thought that the bike was a lash-up from spare parts that BSA had when the bike he was first given went bad in practice. Other riders Gene Thiessen and Kenny Eggers (see link) seemed to remember this too, but Kenny Eggers also thought that it had been put together using a spare Daytona engine and the rolling chassis from a roadster swing-arm Shooting Star that had been sent by BSA for dealers to evaluate before these were officially launched in the UK.  More doubt was spread when we saw what appeared to be a spare or wrecked rigid frame in a photo of Thiessen't trailer as he was preparing to drive home to Oregon after Daytona.

Post race photo taken around Gene Thiessen's car - with the 'spare' frame. Left to right are BSA engineer Cyril Halliburn, kneeling Bobby Hill, standing Kenny Eggers, kneeling Dick Klamfoth, unknown standing in white, Gene Thiessen and Al Gunter.

We wondered what kind of accident would be bad enough to need the whole frame and a spare engine to be used, and if it had been that bad you'd wonder why they didn't need a spare rider as well.  The testimony was confusing and uncertain but on the basis that neither you nor I will remember much about this blog in 50 years time, we couldn’t be too hard on the guys to remember much about the bikes they last saw 50 years ago.

So we decided to look for evidence elsewhere and went first to the BSA dispatch records. Did BSA send a Daytona bike with a swing-arm frame? Was there an early dealer evaluation swing-arm Shooting Star? Service sheets and the the despatch records show that BSA did, and produced a couple of spares engine for UK dealer Fron Purslow but I couldn't find any record of a Shooting Star being shipped either with the Daytona bikes or before.


Detail taken from a BSA service sheet


Where next?  I had looked at the pic in the Hopwood book in the past before I was ever involved in Project Daytona and regarded it as a bit of a curiosity, but didn’t think about it much more. Now I looked at it again but this time with the benefit of the research we had done to determine the specification of the rigid Daytona bikes, I saw things I hadn’t before.  For example, the Daytona barrels, the Vokes filter, the Daytona front mudguard, stays and reversed front brake lever were all fitted only to the Daytona bikes but what we had to do was date the Hopwood bike to late 1953, or very early 1954.And there are two features that let us do that.



Image used on dealer promotional poster after the race shows the Daytona pattern front mudguard, pipes and megaphones

First, we knew that the alloy front mudguard was only fitted to the 1954 bikes, in 1955 this was changed to the standard roadster arrangement to placate the AMA’s regulations for homologation after they questioned some of the special used by BSA in 1954 and threatened to ban them. This was only averted at the 11th hour by the counter threat of an injunction from BSA West Coast distributor Hap Alzina that might have prevented the race taking place at all. The AMA capitualted.

Klamfoth's bike in '55. Also a swing-arm bike but shown here to show use of standard mudguards to keep the AMA happy.

Second, the fat girlings fitted to the Hopwood bike were only used very briefly between late 1953 and early 1954 – slimmer Girlings were fitted from late spring onwards.So we had a photo of a bike that was made around the same time as the Daytona bikes and was fitted with all the Daytona specific features.

We also knew that a swing arm bike was made and shipped to Daytona. Unless this was a pic of the bike sent to Fron Purslow, we couldn’t think of any reasons why this bike would be anything other than Klamfoth’s bike or perhaps the prototype of it – and decided to use this as research material for the planned bike build. Now as a quality check, we decided to take the Daytona film we had and blow-up some freeze frames of Klamfoth going round the South turn.As you can see, quality is lamentable, though it does allow us to confirm the front pipe and megaphone location and dimensions.


Still from the '54 film showing the arrangement of pipes, megaphone and number plates

What it also shows, though is a different seat. On the Hopwood pic there is an example of one of the Feridax –like (in 1955 they used actual Feridax seats) racing seats BSA made in-house for the 1954 bikes. In the blow-up pic, a completely different seat has been fitted with what appear to be rivets round the edge of the seat base. Until we know better, we’re assuming that this was a piece of ‘localisation’ applied to Klamfoth’s bike, either because the original was damaged (perhaps the accident Thiessen and Eggers mentioned?) or replaced to satisfy rider preference.


Still from '54 film showing the seat rivets

 We do know that the others bikes had changes made to them once they had arrived in the US to suit the rider’s preference and the most obvious example being the rear brake lever on Egger’s twin which was mounted over the top of the brake plate, rather than underslung.

There are still some details we can only guess at, like the brackets and positioning of the float bowls for which we really need a good close-up shot from either side. But otherwise, we have enough of a blueprint to start work on the bike. In the next feature, I’ll pay attention to some of the Daytona specific parts and how we worked-out dimensions and specification, managed to find them or in one case – persuaded a manufacturer to resume production again just for us.

Roland Pike Autobiography - Chapter 30

Summary of development work

Rather than trying to visually compare inlet ports, we found it best to compare by measuring capacity with valve fitted in cc's using a burette, several engines that were down for power were found to be smaller capacity; 136cc instead of 148cc on an A7 twin, a B34 GS port 117cc extension 128 total induction 245cc.

All bench tests were carried out in uniform manner starting at lowest practical RPM and going up in increments of 250 RPM with no pause. Flash readings were never reported. We did try running power curves in reverse order starting at maximum revs and coming down but decided this gave false high readings.

Sandilands discovered almost by accident that a venturi shape after the carburettor can be 85% of the area of the carburettor body area with no loss of power, in fact it gave a small increase. We did most of our power curves with a flow meter hooked up between fuel tank and carburettor, this gives a valuable check on efficiency and also on correct carburettor settings.

When using two into one exhaust system it is desirable to have each pipe from the cylinder head to the junction of equal length if not carburation may be drastically affected at some point in the range. The way to avoid this problem is to ensure that each pipe has the same length to area ratio, in other words the longer piece will be larger diameter. In our experiments with the short stroke 500cc A7 twin we also found the angle of the two pipes at their intersection was important. I was at MIRA once waiting to use the timing strip whilst a group of Royal Enfield people tried to get the carburation right on one of the 700cc twins fitted with a two into one exhaust system, I noticed they were using the same diameter exhaust pipes of different lengths before the junction. Strangely enough this same rule holds good for induction pipes as found by Guzzi on their later single cylinder racers.

The A7 and A10 connecting rod bolts were originally BSF threads, we changed this to 26 threads per inch cycle threads as we thought larger area at the root of the thread would make a stronger bolt, we had to reduce torque when tightening the big end nuts proportionally, unfortunately someone in the drawing office forgot to tell the engine assembly and several bolts were broken before the error was discovered. Even more strange was the fact the broken bolts only happened to one of the several mechanics assembling the crank assemblies. I was asked to investigate, so sent Arthur Butler up to the engine assembly to watch how they did this torquing up. He returned a little later laughing with a small tobacco tin in his hand, It had plumbers tallow in it, apparently only one mechanic was putting tallow on the threads before tightening, with the results that nuts tightened appreciably more before the torque wrench recorded the correct torque figures. We accordingly tested some bolts with various lubricants on the thread and decided that important bolts such as connecting rod bolts should be assembled clean.

Oil Pumps.The BSA gear type pump is very simple and reliable, at one time we did some tests by simply running a pump on a drill press in a can of oil and measuring the temperature of the oil, we were surprised at how quickly the temperature rose especially as there was not resistance to the flow. On examination of the pump we decided that some oil was being compressed between the two gears, accordingly a small bypass was cut in the cover plate allowing oil to feed back to the inlet side of the pump. Further testing showed practically no heat build up in the oil. Some tests were carried out on A7 (using various viscosity oils, starting with 50 wt and coming down to 40 wt to 30 wt, 20 wt SAE 10 and finally 5 wt. We discovered that normal oil pressure was maintained on the SAE 10 50 wt, 40 wt and 30 wt. At SAE 20 viscosity pressure tended to drop particularly when hot. The engine was stripped at this point to see if the low pressure caused any bearing problems, everything looked pretty good. At SAE 10 wt pressure seemed very low in fact when hot was nil a further examination of the bearings and pistons showed no sign of trouble but the cam followers did not look too happy, starting to score.

A final run was made with SAE 5 wt pressure almost nil when cold, showed nil when hot especially when engine was revved up, finally the timing side main bearing failed. On stripping the engine we found the white metal had melted and run, but no trace of it in the oil or crankcase, when the sealing plugs were removed from the crankshaft the white metal, was found to be inside the oil passages of the crankshaft, the connecting rod bearings appeared to be in good condition. Apparently the light 5 wt oil was thrown outwards to the big end bearings by centrifugal force enough to lubricate the big end bearings adequately but in such quantity that it robbed oil from the main bearings faster than the oil pump could replace it.

One interesting test was when we set up a A10 engine and gearbox unit on the test bed driving the dyno by a short chain, the object was to try and measure the power loss in the gearbox in each gear. We could not measure the power in 1st gear as the dyno was turning too slowly to absorb the considerable torque due to the low gear ratio. As we expected the most efficient gear was 4th, the direct gear.

Surprisingly, 2nd gear was more efficient than 3rd gear due presumably to the fact that 2nd gear wheels were better supported than 3rd. The final part of the test was when we removed the gearbox and clutch and tried to run a fairly long chain from the engine to the dyno direct to see what difference was with gearbox out of action. To our surprise it could not be done, this rather long chain just whipped and banged and would not transmit power. We had to move the engine back on the block and used a short chain. Incidentally the power loss in 3rd gear was about 10% with about 8% loss in 2nd gear as compared with 4th gear with only 2%. One of the lesser known advantages of the eccentric rocker spindles is the ability to adjust the valves whilst the engine is running.

I suggested this to Reg Wilkes one day, however, he did not seem very keen to stand astride a high revving engine with a wrench in either hand so I appointed myself as the rocker manipulator. We started off on the 500 Gold Star race engine at about 5000 rpm with me firmly astride and adjusted each rocker until the maximum power reading was obtained. The engine was then blown cool with the fan and clearance checked, the inlet figure was something like .009" and exhaust a little more. Then the engine was run at 6000rpm and again rockers adjusted for maximum power and cooled down to room temperature and clearances checked, this time the inlet was .006" and exhaust .008".

Next a reading was taken at 6500 rpm and again clearances checked when cool. Now the inlet clearance was down to about .003" and exhaust .006", subsequent checks were made at 7000 rpm and 7500, with some pointed remarks made about what happened to me if the engine shuld blow up while I am astride it. The results at 7000 rpm were clearances Inlet .001" Exhaust .004" at 7500 rpm inlet nil, exhaust clearances .003". These were not exact figures (my memory is not that good) but the general trend was there at the higher revolutions the rockers and push rods were bending and whipping slightly.

Prior to these tests we had always set valve clearances with a cold engine, with inlet push rod just free to rotate and .003" clearance on the exhaust. The normal practice with regard to rocker angle in relation to valve stem has been to arrange for the rocker to be at right angles to the valve stem at half lift, the object being to minimise side thrust and cut down on valve guide wear. In the course of experiments with both the C12 and the A7 engine better running at high revolutions could be obtained when the rocker was at right angles to the valve stem at about l/32"to 1/16" lift. It was thought that this arrangement aligned the valve seat with the valve seat in the head just as the valve was closing, whereas with the common setting at half lift, the rocker side thrust will tip the valve slightly in the guide when seating and will have to realign itself as it seats. At very high revolutions there is not enough time for this and some efficiency will be lost. On the C12 this was visible even by turning the engine by hand, by inserting some packing between the rocker mounts and the head we were able to see the improved action. It is quite possible that most overhead valve engines using rockers could benefit from this rearrangement of rocker angles.

One unexpected results when trying a much larger and stiffer crankpin with plain bearing was considerable difficulty in lining up the flywheel assembly, presumably the wider shoulders made the assembly more rigid. Engine gaskets between rocker box and cylinder head usually made of paper were replaced with metal corrugated gaskets, these could be used over and over again and sealed better.

During the five years I was at BSA doing engine development I was fortunate in attracting some very bright and enthusiastic mechanics and apprentices, they all contributed to the progress we made with development of the BSA range. There was tendency to specialise but most could handle anything that came in the shop. Jimmy Gibbard did most of the odd machinery jobs, Jack Turner did the intricate inlet port arrangements and exploited the extra down draft angles and straight ports. Reg Wilkes, Bert Hole, Arthur Butler, Arthur Bridgewood, Bill Bently and Alan Sandilands could handle any aspect of engine building , the apprentices who spent more than average time with us were Gordon Smith, Robert Trigg, Ray Beech, David Harris and John Taft. Albert Dyde, ??? Harrison Ward and Hill came into the shop later. We also had some colonials like Barry Stormont and Cohn Mather during the winter months. I learned a great deal and was able to try out many ideas that I could never have done in the ordinary way, for this I am grateful to Mr Hopwood and BSA for this opportunity.

One of the chief abilities necessary in this type of work is to be able to 'sell' ideas to the Management, something I was not very good at. Thanks to BSA sending me to the USA on business trips I decided to emigrate and have had an interesting life in USA becoming a citizen in 1982, finally having my own business and a and a decent workshop including a dynomometer. I have not lost interest in motorcycles and at 75 own a 250cc Kawasaki 'Ninja', a remarkable little machine with a performance in road trim better than my old racers. We still enjoy trips to Road Atlanta to watch the motor cycle road each year.

Roland Pike Autobiogarphy - Chapter 28

My trips to the USA

The BSA representatives in the USA, Alf Childs in the east and Hap Alzina on the west coast both realised the importance of racing for sales success in this market, and both were in favour of factory co-operation in these endeavours. In 1952 Alf Childs was in England for the Motor Cycle Show and while at the factory told the Board of Directors that he wanted someone to come over for several weeks and run a service school. Someone who can talk to the Dealers in their own language and who had some personality. I understand there was some talk of sending Fred Rist, he had been over before and had gone down very well, but he was not a technical man. Mr Hopwood suggested that perhaps they would like to meet Pike, he had been a motor cycle racer, has had experience and would be interesting to the Dealers and racers.

The first I heard of this suggestion was when I received a telephone summons to Mr Leake’s office, my first thought was to wonder what I had done wrong. After a quick tidy up I went up to the office and was escorted by Mr Leake’s secretary to the boardroom where the Directors, Mr Hopwood and Alf Child were waiting. They introduced me to Mr Child who sized me up and said I looked a dignified young man and how would I like to go to the States and run a service school? I looked across to Mr Hopwood and asked if he thought I knew enough about the rest of the bikes, and he said he would arrange it for me to obtain the necessary knowledge if I thought I could run a school. It was all laid on very quickly, the Motor Cycle show was in October and I was wanted in the States by November. It meant I had to get an American visa, smallpox vaccination and renew my passport and book my passage by boat. Passage was booked on the 14,000 ton cargo boat ???Media which had accommodation for 100 or so passengers, first class only. My wife and daughter accompanied me to Liverpool, we were taken in style in a company car driven by Mr Leake’s chauffeur. The ship left from the Prince of Wales landing stage the same as for the IOM packets. The ship moved out into mid channel and then just sat at anchor and on enquiry a crewman said they were waiting for flood tide. The boat drew a lot of water when loaded. I do not know what else it was loaded with but I do know it contained 14 BSA bikes that were being sent along for the service seminars. They were all painted in non-standard colours to get the Dealers reactions, this was due to a request by Alf Child, they were in chocolate, green, red, silver, you name it. As it turned out the Dealers preferred the standard colours.

The next morning when I came up on deck somebody said we were about to pass the south coast of Ireland, with my binoculars I was unable to see anything as it was rolling so much and in fact I felt quite queasy and also cold, so I went below. I had never been on a boat as big before, the cross channel boats and those that cross to the I0M were all under 3000 tons, even the boats to Belfast were around 4000 only. So the Media seemed quite big. It was fitted with Denny Brown stabilisers which cut down the rolling but not the pitching at times it would rise and fall over 20 feet, like riding a roller coaster. I had a short bout of 'mal de mer' but soon recovered and enjoyed the rest of the trip. A good many passengers spent the whole crossing below. Actually it was not a big liner and there was not much room, a small library, large lounge, a smoking room and bar and a dining room. There was a walk way round the Back to top deck, glass enclosed that if you marched around seven or eight times made up a mile. There were several friendly passengers which helped pass the time swapping yarns. Every evening at about 6 pm various ships officers invited odd passengers to their cabins for cocktails. I went to the Captains quarters one evening and also to the chief engineers cabin another time. At one of these functions I met Chris Morley the author and had a most interesting chat. Many of the American passengers tried to impress upon me how expensive I was going to find things in New York and I began to wonder if the seven pounds a day allowance I had would be enough.

Due to the rather rough crossing the boat was slowed and the trip took eight days instead of the usual six or seven scheduled. We finally arrived in New York harbour on a Sunday morning. I had never seen so many cars and traffic on the beltway. As we only had about 100 or so passengers the immigration check was soon carried out, not like on the 'Queens' where you had to stand in line for ages. The customs was a different matter, I had some films with me for use in the school, I had borrowed them from Castrol and Shell such as Geoff Dukes' 1950 TT and some Scrambler footage. Customs were quite awkward about them, wanting to keep them to check if they were pornographic. Fortunately I was met at the pier by Roy Bradley and Geoff Floyston from BSA and Malcolm ???2~lue of Castrol. Malcolm had lived for years in the States, he had come over originally to play soccer after WW1, he had a great personality and soon persuaded Customs that they were harmless.

When we went ashore Roy said they were going to show me a bit of New York, Malcolm however fancied a drink but the bars were not open so we went in a little coffee shop across from the pier, my first experience of a 'diner'., The place was full of longshoremen and sailors from the Cunard and White Star liners that were tied up there. In those days most everyone came to the States by boat and the docks were always busy, now its like a ghost town except for the odd Cruise ships. I still felt as though I was going up and down, after you get your sea legs it takes some time to get steady again. The lads were all for taking a cab but I felt I would rather take a walk as I had little exercise whilst aboard. So we walked up about 8th Avenue where they found a bar open, I settled for a beer not being a drinking man, they others fancied something more lethal. After Malcolm left us we took a subway to Times Square and we went to Jack Dempsey's restaurant for lunch and I enjoyed my first meal American style. There was an English movie then playing on Broadway called "Sound Barrier" so we went to watch this, later we collected my luggage from a locker in the bus terminal and ??? into our car.

After driving through the Lincoln Tunnel we passed through towns with to me strange names like Hackensack and Passaic finally reaching Nutley, NJ where I booked into a motel for one night with the arrangement that Roy would pick me up in the morning and have breakfast together. The motel was steam heated, and I having always been used to cold bedrooms opened up the windows as I felt I could not stand the stuffy atmosphere, however by morning it was cold enough for me to regret being so rash. After breakfast Roy took me to Rich Child Cycle Co and I was introduced to a bewildering crowd of characters, most of whose names I forgot almost immediately.

The schedule arranged for me was to, start a school that same morning which did not leave me much time to prepare, none of the bikes or literature had arrived but I did have the two films. It was my first introduction to American motorcyclists who appeared to me to be in some type of uniform, leather jackets and peaked hats not unlike Nazi Storm troopers and some had Harley Davidson emblems on. They appeared to be a tough looking crowd but in actual fact were a friendly bunch. We soon settled in-to the Service Department which Bill Carlton the Rich Child mechanic had turned into a class room for the week with blackboard, easel and chairs. Showing one of the films gave the fellows a chance to relax as most had been travelling over the weekend to attend the school. One had ridden his Star twin all the way from El Paso in Texas 2,500 miles, and he was not a youngster either, it had taken him nearly a week. In talking to these Dealers during the lunch break and in the evenings when we went out to eat I discovered that most of them were working as dealers part time, one of them ran a radio and electrical shop, motor cycles were a side line. Another worked in a factory all day whilst his wife ran the bike shop and he sold and serviced bikes in the evening. If he sold a couple of bikes a month he was happy. There was one who ran a full time shop in New Jersey and another in Washington, Long Island , but these were the exception. Most worked only part time in the cycle business which may be why BSA did not sell as many bikes as Honda did later on, as Honda built up a proper dealership network.

Shortly we had our materials unpacked and talked about the new models and what was coming along for 1953. They were interested in what I did at BSA and how the factory was organised, we showed the films of Scramblers and of the Ulster Grand Prix in the wet in 1948. They could not understand how the bike could do 100-120mph in the pouring rain and not slide off the road. They were also interested in my own racing experiences.

The actual Service part of the course was a bit haphazard, some would bring up a problem, we would discuss what we knew of it and a possible cure, to me it did not seem they we were accomplishing very much, but they went away at the end of the week apparently quite satisfied. On the Friday we went into some details of the Ariels, which I knew only a little about but Bill Carlton and one of the roadmen were able to cope quite adequately. Alf Child, Roy Bradbury and myself sat down on the Saturday and held a review of the first week, Alf wanted more emphasis on sales, so Roy had to lay on a bit of high pressure stuff and he suggested I talk more about the Star twin, so I prepared for that. The second week with a fresh group of Dealers went off better. Roy warned me that the third week was likely to be the toughest as the Dealers expected were practical men and likely to be argumentative. He kindly pointed out the most likely trouble shooters, one in particular was Herb Suddeth but as it turned out he was the most helpful co-operative pupil of the whole three weeks and I got along with him extremely well. Another pupil Sam Avelino who came from New England told me he had worked in the ship yards during WW2 repairing a number of British boats and he hoped I was not going back on any he had worked on because they were bound to have engine trouble. On hearing I was returning to GB on the Brittanic he was shocked and said it was a terrible boat and always breaking down, at that time I thought he was all bull, he said it had two big diesels that went wrong every trip. Sure enough on the journey home I noticed ,early one morning the thump thump thump of the engines was absent and on enquiry, I happened to be having breakfast at the Chief Engineers table, he said the inevitable engine breakdown had taken place with the old engines.

Fortunately they had a complete workshop down below and were used to having to' fix the engines, they were working on the one that had broken down, they had stopped both diesels as it was easier to work on them. Due to my interest he arranged for me to have a tour of the engine room and a young engineer was my guide, after donning a set of white coveralls, the two of us squeezed into a tiny lift and shot down into the bowels of the ship. It was pretty crummy compared to the spotless oil fuel steam turbines on the Media which I had visited on my trip over, to the US There were two big diesels twenty cylinders ten in a row but double acting like a steam engine, they were made in Ireland by Harland and Wolf. One of their problems was breaking valve springs, they used to stop the engine and change them, these engines ran on absolute crude oil, black globby dirty stuff which was fed through a De Lavel centrifugal separator just like those used in a dairy! Each cylinder had its own injector operated by the camshaft, to run the ship backwards they did not change gear but stopped the engine and reversed it. In order to reverse its operating rotation, this being a four stroke engine, they slid the camshafts along to an alternative position, so that a different set of cams came into play. In the meantime all the cam followers were held up by a sort of rack. The engine was then restarted in the reverse direction with compressed air, this accounted why this type of boat is not easily manoeuvred as a steam powered one.

The Brittanic had twin screws and was very broad beamed and weighed about 32,000 tons. Despite the breakdown I thought it very comfortable trip even though it was rough the passengers barely noticed any discomfort. The last week of the four I spent in the USA there was no school and we spent some time sorting out Rich Childs service problems. One day I took a day off and Bill Carlton and I went off to see Triumphs at Towson near Baltimore, Maryland.. The Service Manager at that time was Rod Coates, a great competition rider, Rod had won the 100 mile Amateur race at Daytona Beach in 1950 on a Triumph Grand Prix model. He showed me a special racer with all the wangles and fiddles he had conjured up to make it eligible for AMA class C racing. Later when be became an AMA scrutineer I am told he was not nearly as lenient as be had found the officials in his day as a racer. We very much admired the set up, of Triumphs at Towson which had been custom designed and built specifically as a motor cycle distributorship. BSA was running what was originally a car dealers premises in Nutley, however it was adequate for all that, it had a good parts department and a large showroom, although what good a showroom in Nutley I could not fathom. Whilst at Towson I met Dennis McCormack who managed the Triumph distributorship for years. Alf Child did not like us going down to see the Triumph outfit but as BSA had bought up Triumphs he could not really complain, he always regarded them as the opposition instead of a sister company.

During my stay in Nutley I was fortunate after a false start to find accommodation with Bill Carlton at a very pleasant house, the landlady Mrs Weidlich was a very pleasant widow around 70. I enjoyed staying with her and went back again on my second visit to the States in 1953. It was about seven or eight miles from Nutley but I was able to ride in with Bill Carlton each day.

On my return to the factory I had to give a report of my trip for the management and it was read out at a meeting and met with their approval, so much so that I was asked if I would be willing to go again in 1953 to Daytona. I knew many of the US dealers had asked if I could come for Daytona as they thought I would learn a great deal more of their requirements for short track events. Evidently Alf Child had approached Mr Leake with their request. The results were that in February 1953 I was aboard the Queen Elizabeth heading for the States. This time I sailed from Southampton and it was much more 'de luxe', even Cabin Class on the Elizabeth was more comfortable than first class on the Media. The voyage across was luxurious but uneventful, I spent three days at Nutley preparing for the trip to Daytona. Alf Child and Mrs were flying and wanted to take me but I preferred going by road with Bill Carlton as I felt it would give me more time to see the country. We were taking a half ton van loaded with all manner of spares, even complete engines, catalogues and literature for the bike show in Daytona. The van was so well loaded it had a tendency to wander and was very tough to drive. We did not get started till midday and it was snowing lightly, which did not make for a pleasant drive, just as it was getting dark we fancied something to drink so pulled off into a diner just into Maryland on Highway 301. Bill ordered coffee and asked for tea for me, the waitress recognised my accent and remarked as I was from England I would like a proper cuppa, she reached to a shelf and took down a teapot, which she dusted off and made me a decent pot of tea. I thought this rather good after being served in other places with the inevitable tea bag flopped into hot water.

We pushed on finally stopping at a motel in Maryland. Next morning we made an early start, sBack to topping in Virginia for breakfast. We took turns at driving and I remember passing lots of tobacco factories around Rocky Mount, NC we stopped finally for the night near Allendale, SC. We were really beat after driving that over loaded truck all day. Next morning was a sunny mild southern day and drive through Georgia down towards the coastal swamps, which did not impress me at all. By the end of the day we had reached Jacksonville, Florida where we visited the BSA dealer Bob King who was a great pal of Bill Carlton. Bob found us a motel close by and to our amusement were installed in the bridal suite. Next day we visited a dirt track meeting just outside Jacksonville. My first introduction to dirt track in the US, with some smart talk by Bill persuaded the officials that we had factory authorisation so between races we were allowed to cross the track to the pits. After watching two or three heats came the big final and we had been told to look out for Bobby Hill on his Indian. It was a sort of borderline eligibility case and a lot of folk opined it should not have been allowed on the track. It was a 750cc side valve though it had a lot of one off, non Indian parts on it. It had got passed the scrutineers by pointing out that Indians were not longer made and it was impossible to get genuine Indian parts and they used what they could find. The bike had modern forks and superior looking brakes that no Indian ever had. It was however, a genuine Indian flathead 750cc, very highly tuned with a ultra light frame.

Came the start of the big race and Bobby Hill stalled his engine, it looked as if the chance for a win by the number one champion was nil, all the competing BSA twins, BSA Gold Stars, Triumphs and Harleys were long gone, however the referee motioned to Hills mechanic to give him a push start and away he went. It was a twenty lap race event and unbelievably Hill worked his way up through the field to win. I had never seen anything like it, that was my first introduction to Bobby Hill. Later he used BSA doing extremely well on them, winning Daytona in 1954 on a clubman type twin.

After the racing we returned to Bob Kings staying another night in the motel. Next morning after some difficulty to change some GB travellers cheques only by going to a bank we drove on down to Daytona Beach, we found ourselves an apartment about two miles down the beach, we did this on advice from Cyril Halliburn and Bob King to avoid having riders bother us twenty fours hours a day. It was a very nice place with a view of the ocean but rather far out and you needed transportation to get to the BSA headquarters which that year were in the old Hudson dealers service department. We had the use of half the garage for BSA servicing and all the dealers and their riders came crowding in, talking and getting in the way. Alter unpacking our parts and tools we proceeded to service our machines. This being 1953 all we had were the heavy plunger rear suspension, iron barrel, alloy cylinder head Star twins. They were supposed to put out 43bhp, but we were experiencing valve spring problems. The prototype built in the Engine Development did put out 43bhp but all the Star Twins sent to Daytona were built by Production and tested in the engine test by Cyril Halliburn, who issued power curves showing 43bhp but when we got them to the beach for practice it was obvious that they did not have the power and were getting passed by all and sundry.

There were three of the previous years Star twins there, one of which had been hand built by Jack Amott, it was considerably faster than the new 1953 models. I would have liked to get a look inside that engine. In the race these wretched twins we had brought folded up one after the other, Warren Sherwood nursed his home into fifth place, the rest were nowhere. Paul Goldsmith won on a Harley and was sporting enough to come over to us and commiserate. One of our riders fell of and broke a leg. I persuaded Alf Child who owned the machine anyway, since the Dealer now declined to pay for it, to let me take it back to the factory and test it on my dyno, to which he agreed, remarking they were not as good as the previous years machines. As you can imagine he was pretty miffed with me, the bikes and the race results. I did not feel it was my fault as I had only been at BSA ten months and had not built any of These machines. The company was not too pleased to see the crashed bike but Bert Hopwood agreed that it was a good idea to test it and rind out why it was running as it did arid to then try and get the bugs out of it. Back on the dyno we got 39bhp and it took a good deal of work to get it up to 43.

The Directors asked me to come and give them a talk on my experiences in the US at Daytona particularly, as Alf Child had complained to them about me. Naturally I was not going to let him get away with this and I told my side of the story, particularly my dislike of being sworn at in a hotel in front of a whole crowd of people. Mr Leake wanted to know the exact wording which I was not keen to repeat, but he insisted, he queried my repeating and wanted to know why such an occasion had occurred. It was due to my late arrival at the garage to work on the bikes and I explained to Mr Leake we were situated nearly three miles from the garage and it was difficult to get a lift and on this particular morrning they had forgotten to collect me as arranged. Mr Leake appeared rather annoyed with Alf Child and complained to him of his attitude, this in turn upset Alf Child and I did not get invited to Daytona again.

During my two trips to the USA I had the opportunity to talk to some knowledgeable dealers and our Distributors and the impression I got was that whilst Daytona was an important event there were many other races in other parts of the States of equal importance to the sale of BSA It appeared they wanted lighter machines that could be used on the half mile and one mile tracks as well, a rigid frame but telescopic forks. I pointed out to them this was against everything we had been doing. In the IOM we had been busy developing swinging arm suspension and now the States wanted rigid frames and I was not at all sure the company would be willing to make them.

On my return to the factory I had a conference with Hopwood and Bert Perrigo and told them of the Dealers requests. I pointed out that Daytona consisted of two straights both fairly smooth, one on sand and one paved with 180 degree turns at each end, there was not real cornering involved so I did not believe a spring frame was essential and that a rigid frame might be just the thing for the hale mile tracks. They also wanted to know what type of engine would be best and I suggested the single would be lighter and have better torque but they argued it probably would not have enough power, but I pointed out the superior torque and reliability. In the end Hopwood said why not go ahead and make a prototype and see what we can come up with. This was the summer of 1953, our alloy twin race engine was producing about 44bhp, the best 500cc BB Gold Star single about 40. We were planning new bigger finned Gold Stars for the Clubmans TT races but they would not be ready until after Daytona, but the 350 BB Gold Star had had a new head with slightly more finning than the old ZB and much steeper down draft inlet port. So I got the engine shop to machine one of the 350 cylinder heads to 500 dimensions, the hemisphere was enlarged and 500 valve seats fitted, we used a large inlet valve and a moderately sized exhaust valve, of course doing this left things a bit thin in places but we cut up a scrap head and decided it was a worthwhile risk. On its first test run a 500 with this head did 42bhp despite the AMA restricting us to a 8:1 compression ratio. I put Reg Wilkes to work an this, he got real interested in this and tried everything and soon got 44bhp .

In the meantime the twin was also doing some 46bhp. To meet AMA regulations all parts had to be stock and have production part numbers and available to the public. So I drew one of Bill Nicholson's lightweight rigid trials frames and started work on it, we stiffened up the rear chain stays, made an oil tank from toolbox pressings mounting it low ,on the right side. We used aluminium alloy for the mudguards, chain guard, brake pedal and fork crown. Ultimately we made three prototypes in the Engine development shop, we got some extra help from apprentices, at one time having eighteen men in the shop in place of the normal seven or eight. We fitted a single cylinder engine in one frame and our best alloy twin in the other and gave the third to the production people to copy as we knew that possibly another hundred would have to be made.

The big day came when we took the two prototypes to MIRA. For our testing, we ran them in both directions on the timing strip, the single did 114mph, the twin 116. Mr Hopwood was of the opinion we would have to take the twin, two miles an hour was a lot and at the end of a 200 miles at Daytona that bike would be miles ahead. I did not agree and he wanted to know why. He was aware I liked the single and that it was reliable but it did not appear fast enough and therefore it was no use taking it. I pointed out that in racing it's not always the fastest bike that wins. Torque is important and the winning prize goes to the first across the line, not the one that crosses at the highest speed. He was anxious whether I could prove this theory. David Tye had his leathers on and so did I, he got aboard the twin and I got astride the single. We agreed to race by riding at about 20mph in bottom gear then as we passed a little white post open up for a sprint of about a mile. The torque of the single was so much better than that of the twin that it leapt away from the 20mph start and simply ran away, towards the end of the mile the twin started to catch up, because of its slightly higher maximum speed, but the single still got to the end first. Back in the pits Hopwood said to change bikes and try again to see if the rider influences the result, so we changed over and sure enough the result was the same. Hopwood looked at me and grinned and agreed I had made my point and that we would send four singles and four twins.

The results were better than we even hoped for, we won the 200 mile race and had five out of the first eight finishers. Gene Thiessen had the bad luck to have his bike damaged going up to the start which spoilt the handling and he finished 17th. The rest of the season BSA did very well on the half mile tracks. Many years later in 1970 when these bikes were quite old I saw two of these models at Reading Speedway in Pennsylvania still giving a good account of themselves.

The early CB and Daytona engines had oval flywheels with a short connecting rod from the 350, which we had found gave good results The short connecting rod enabled us to use shorter barrel push rods and so on and made it lighter. Not to mention other more subtle technical advantages. The flywheels were made oval to clear the bottom of the piston skirt, this was fine for us making a handful of experimental engines but when the production people had to make a hundred of them they complained bitterly. One day Reg Wilkes took a pair of oval flywheels and turned them down until they were round again and we tried these lightened flywheels in a bike, frankly I did not think the engine was as smooth, but the riders thought otherwise so that is how they were made from then on and that was the beginning of the DB series. The shorter connecting rod definitely gave us something, a little more power all over the range, I have carried out the same trick on VW engines and again found the shorter rod was better. In 1954 at Daytona the Harleys gave more trouble than usual so we had a bit of a walk over, but in 1955 the tables were turned, they had some excellent riders and the best we could manage was a 4th place. In 1956 we did fairly well to take 2nd to 5th places, a Harley won. Al Gunter made the fastest lap in the race at over 104mph before retiring with a broken swing arm bolt on the BSA single. In the time trials before the race the fastest Harley did 126mph The fastest Gold Star was around 120mph. Despite this the Gold Star was a match for the Harleys during the race.

Roland Pike Autobiography - Chapter 22

The Terrible Twins

I have never liked the air cooled vertical twin, but they looked neat, were simple, had an even firing, smooth exhaust note, fitting neatly into the same frame as their predecessors, the singles. The vibration was terrible, it seemed worse than the single, at least it was more noticeable. To my mind the head joint on all vertical twins with one-piece heads and cylinder block was marginal and subject to distortion. At BSA we must have done a fantastic amount of work on twins, judging by my notes. BSA had made up their minds that the twin was the motor cycle engine of the future. Every time I rode one it gave me the willies - the vibration was so noticeable. We tried all sorts of cures to get rid of the shakes and I still think our best ever effort in that direction was a short stroke 500 we made in 1953. Charlie Salt & I ran and ran it until we wore it out but no one seemed interested in it. This short stroke engine was a 500 A7 using a 650 head, barrel and pistons slightly modified. The crank was machined from the solid. This arrangement gave a 70 x 64.5 bore and stroke and instead of having a bolt on flywheel it had a triangular bob weight machined in the centre of the crank and discs next to the journal bearings. It was a very smooth running engine, both on the dyno and on the road. Power output was similar to the Star Twin, using 7.25:1 compression ratio.

With further tuning and lighter valve gear it gave 36bhp at 7000 a specially developed two into one exhaust system, we got as much as 39 horsepower at 7000. It was a most exciting machine to ride, as you accelerated it went on a normal power curve, then suddenly the exhaust note would change and it would 'yowl' right on up to maximum about 107mph Back in 1953 on low octane petrol this was quite an exciting performance on the road. Charlie and I enjoyed that engine.

The so-called Star Twin camshaft was a sporty one designed I think by Jack Amott although the design office never gave him credit for it. It was quite useable on the road with silencers fitted and also useful with open pipes. The fellows in my shop told me Jack did all the work on cams and I have no reason to doubt their words. Later on we went to the Daytona camshaft which was really a race cam and not very good at low revs but good at high speeds. Amott did design a racing cam for the twin, but we were unable to make it work properly, it was too radical and hard on valve springs. Reg Wilkes mentioned that if the drawing office had stuck to Jack’s original design they would have been all right. I asked to see Amott's original design and Reg got his camshaft out of a cabinet and showed it to me. It had a much larger base circle than the drawing office version, although to be quite honest I could not see what effect this would have. Wilkes suggested I try it sometime, he was sure it would work better and it did. It was still pretty radical. I never could understand why the drawing office decided to change the base circle diameter. One of the disadvantages of a larger base circle is a higher rubbing speed on the other hand you can get a smoother easier ???

Twin camshaft problems. Whilst working at BSA Dennis Lashmar carried on racing my old 'Pike BSA' with the alloy twin engine. I think he had one good win on a wet day at Snetterton, when it ran cool enough not to blow up. Latterly whenever we went to Silverstone or anywhere to watch him, he finished up sliding along on his backside at about 100mph with a broken crankshaft. This was too dangerous I considered. Once just after the massed start at Silverstone, with the pack all bunched up and approaching Woodcote corner at over 100mph the Beesa suddenly seized and he was sliding along with bikes all round him! I told Mr Hopwood that if we could not do something about the crankshaft breakages we should drop the racing twin. He pointed out that as far as Lashmar was concerned it was his own bike and he could do what he liked with it, but the policy of the factory was to make a twin. I felt we should make a new crank for it to which he agreed and wanted to know if I had any suggestions. By this time Group Research were in the picture at BSA and they demonstrated to me in ten minutes what I had suspected for years. They came up with some very good ideas. One was that the crank needed larger crankpin journals .which would make it stiffer and get away from the frequency at which it now vibrated. Mr Hopwood agreed that their suggestions were fine for 1955 but at that time we had to use what we had. He was interested to know if any other suggestions and Group Research said to put a rolled radius around the ends of each crankpin. They demonstrated by putting a standard crankshaft on vee blocks over the Back to top of the electro-magnetic vibrator they had built.

Then started some sort of motor generator. The noise was like standing next to a jet engine at the airport, it went into a scream and from a scream to an outer pitch sound, onto another phase even higher, then they brought in the electro-magnetic vibrator and the whole place began to buzz. The frequency of the vibrator was adjusted to a multiple of 6,600, the crank vibrated with a high speed buzz, inside ten minutes there was a loud bang, the crank fell in two parts, broken at the usual point, showing the same sort of fracture that we had experienced after three hours running at 6600 RPM. It was a much quicker way of testing a crankshaft and without wrecking an engine. Next they set up one of their special cranks, with the rolled filet radius on the crankpin, it was subjected to the same test, buzzing away on the vee blocks, ten minutes passed, thirty minutes and it was still in one piece. I got tired of waiting and asked to be informed when it broke. It did not break and after one hour it was still good. I was very impressed and so was Mr Hopwood but the factory again did not seem interested, perhaps they could not believe it. This rolling process consisted of applying a ball ended tool to the radius under high pressure in a big lathe.

A few cranks were made, some for research, some for use on the dyno. It seemed fantastic that this simple process could make such a difference. Many years later when I was working for Volkwagen in the USA. I discovered that they cured a rash of broken crankshafts on the 1965 truck engine by the same procedure, except that they did not use a ball, but a small roller to form the radius. It cured the problem for Volkswagen.

Twin engines for Formula 3 We made a number of A7 race engines for this small race class in 1953. They were set up to run on alcohol fuel but were not very reliable and although we got close on 50bhp were repeatedly beaten by Norton singles doing far less. We actually 'borrowed' a 500 Norton engine designed for a formula 3 car, it pulled 42bhp but had 39 ft lbs of torgue against our 36 ft lbs. Part of the trouble with our engines was the installation, they did not get enough cooling air and in one case they had a restricted oil supply, using a long small bore hose from the tank to the engine, the sticky Castor oil simply would not flow fast enough. Another problem was at the head to cylinder block joint, there was a tendency when very hot for a slight blow across to the oil drain holes thus pressurising the crankcase, this blew oil out of the crankcase at every possible point. The cure was to fit small hollow dowels into the head and barrel joint, thus rigidly locating the head, and keeping gas pressure out of the crankcase.

The single overhead camshaft A7 In 1952 they were working on a single overhead camshaft 500 twin. It was a handsome engine with alloy head and barrel, fine pitch finning, exhaust pipe held to the head by nuts. The single overhead cam was driven by bevel gears and a shaft running up what would normally be the push rod tunnel, the valves were operated by rockers. Arthur Bridgewood was working on it in great secrecy in a little shop at the end of the test shop, he had to put up with the noise and fumes of engines being tested. At this point in time it gave the same power as the A7 push rod engine and broke crankshafts with equal regularity. The camshaft was lubricated by the rocker feed which was completely inadequate and of course it wore out cams and nd rockers. Doug Hele suggested using a single wide cam as they did on some Ariels. This cured the rapid wear but the performance suffered due to the geometry of the rockers to cams, one rocker being a trailing rocker, the other a leading one this giving different opening diagram for each valve. I personally felt that the engine could have been made to go if I had been given more freedom as I had with the Gold Star and MC4. One problem was excessive oil consumption due to an accumulation of oil in the rocker box which ran down the valve guides. This we cured by using a C11 oil scavenger pump to pump surplus oil direct to the tank. The feed side of the little oil pump was used to squirt oil through 1/16th holes on to the cam lobes, this cured the rocker and cam wear. At this point we needed a stronger crankshaft and a different design of cams to take advantage off the overhead cam arrangement. By this time Mr Hopwood had lost interest in the engine and said he did not think it would ever be any good, so scrap it. I think that’s what finally happened to it.

The A10 was if anything worse than the A7 when it came to vibration and crankshaft breakages because of its longer stroke. Actually most complaints were about the A10. Although the A7 was the one we raced so that we were more intimately involved in its development. BSA brought about their own demise by their attitude to progress. A favourite saying of Mr Leakes was "Don’t let us be pioneers". Back in the dim and distant past they had lost money on a few experimental ideas that had not worked and that had never been forgotten. Nevertheless when you are the biggest motor cycle manufacturer s in the world you have got to do some pioneering if you want to stay on Back to top. You cannot leave it to small firms like Velocette, who introduced foot gear-change, a successful spring frame, eccentric rocker spindles, a production overhead camshaft engine and many other innovations.

Alloy heads for the twins About the beginning of 1954 it was decided to make a production version of the twin with an alloy head, we had made experimental ones before for the racing people. The head had shrunk in valve seats which gave very little trouble but the spark plugs fitted into bronze inserts screwed and pinned into the head, these persisted in coming out when the plug was removed. I persuaded Mr Hopwood to use long reach plugs screwed directly into the aluminium head, this was very satisfactory. At one stage we could not make a decision on which was best, a single inlet port and one carburettor or twin ports and two carburettors, on the dyno there was very little in it. The first of the Star twins had twin port heads with detachable manifold, it could be used with either one or two carburettors. In point of fact the difference in power is only worth while when running on open pipes. Twin carbs and their cables have to be carefully adjusted to keep both cylinders pulling equally at small throttle openings and just off idling, which is a nuisance to the rider at best, assuming he can cope with the bit of DIY mechanical skill necessary.

After a year we had improved the port configuration and it ran so much better with one big carb that the twin carb option was dropped. We had found it useful to measure the capacity of the inlet ports and check on performance, about 142 to 150cc's gave optimum results. If an engine was down for power we often found the ports undersize. Like all aluminium cylinder heads, these expanded a lot with heads and at the outset we experienced stretched or broken head bolts. These bolts went downwards through the head into the iron cylinder block and would usually break at the root of the last thread, which was the weakest point because it took all the stretching. To overcome this we quite simply put the bolts in a lathe and reducing the diameter of the pIain portion to 10% less than the diameter of the root of the thread. This meant that the thread was no longer the weakest point and that the plain portion could stretch without exceeding its elastic limit.

This was completely successful on the first attempt and no more trouble was experienced with the bolts. They could stretch when the head expanded and return to their original length as the head cooled own. When the new twins were going into production however, Alan Jones who was Works Manager at that time phoned me to say they were unable to make the head bolt as needed, despite my pointing out that we bad found them necessary, he just continued to say they were unable to make them. I went on with my work and forgot about the matter, but I did not have to wait long, within a few hours the motor cycle test shop foreman was on the phone to me complaining the head bolts of the new twins were breaking right and left, so I referred him to Alan Jones. Mr Jones reiterated they were unable to make the bolts we had designed. Prior to this last call I had taken the precaution of calling the drawing office to say that Jones would not follow their drawings of the bolt thus securing an ally. Alan Jones got no sympathy when he had to pull all the bikes concerned back, dismantle the engines and use the bolt we had specified.

Roland Pike Autobiography Chapter 18

The Development Shop and Clubmans TT

The primary aim of my development shop at BSA apart from improving standard machines was to win the Clubmans TT. We were not supposed to be interested in International racing, other than in connection with the MC1 project. The scrambler motor was considered powerful enough. For the Clubmans models we were always searching for a little more speed and of course reliability. This went hand in hand with American class ‘C’ AMA racing, since what was good for the Clubmans was also good for class ‘C’.

BSA did not dominate the early Clubmans 500cc TT races which were won mainly by Triumph and Norton. The 1949 race for 350cc was BSA's first victory. Many BSA 350's were entered and few finished but that year the winner was a BSA.

They had plunger rear suspension, leaked oil, and tended to blow oil out of the engine breather, to the extent of running low on oil, causing seizures etc. Nevertheless, the two or three best BSAs on that occasion did very well, competing against Velocette KSS models and 350 Norton Internationals. In 1952 BSA had hoped to provide a challenge in the 500cc Clubmans with an all alloy twin engine which would be promoted as Gold Star Twin if successful.

However the regulations prevented their use as it was not yet a production model. A few standard A7 500cc twins were built to Clubmans specifications, they pushed out 36-38bhp which was about the same as the production Manx Norton, but in fact were unreliable and had a peaky performance, also did not handle as well as the single. In 1953 it was the same story, the old CB350 did quite well as did the 500cc singles of which there were two or three entered.

The 500cc BSA twins were getting pretty unpopular by that time because when the crankshaft broke, they often destroyed the crankcases and fetched the rider off. If this happens at 100mph it’s pretty scary. Triumphs were still going strong with their 500cc twins although they had their share of blown engines too. They won by the use of specially prepared hand picked machines and some good riders. By 1954 the Gold Star had new heads with big area finning, eccentric rocker spindles, shorter connecting rods, tubular push rods (instead of solid alloy) and Nimonic exhaust valves, a timed crankcase breather (which controlled the tendency to blow oil out on to the road and rear tires) and needle roller bearings on the gearbox layshaft. So far as factory involvement in preparing machines for the Clubmans went there was none, however we used to maintain a workshop in the Island for the benefit of all riders of BSAs. The riders who showed the best in practice might get the benefit of someone like Cyril Halliburn working on their motors. Triumph and Norton did the same thing.

Triumph had Ernie Nott an ex- TT winner working on some of their customers’ bikes. I was in the Island workshop keeping an eye on technical problems and helping Charlie Salt with his TT machines. Before coming to BSA Hopwood had designed the Norton twin, its outstanding feature was the way the cylinder heads were splayed, cut at the front giving better cooling and more fins where needed. This feature was patented, so of course could not be used by BSA.

Nevertheless the new A7 he designed for 1952 was a good rugged engine compared with the earlier BSA twins. It had a weak point in the timing side main bearing and rather small tappets, they wore more rapidly than they should, and also a tendency to vibrate and break crankshafts. We carried out a lot of tests to improve the timing side main bearing trying an all white metal bearing, a copper-lead bearing and a needle roller bearing. This last was far and away the best but required a different oil feed to the crankshaft to lubricate the rod bearings but as the factory did not want to make a change, we continued with the short life main bearing. The crankshaft breakage problem was really due to two things, the diameter of the crankshaft rod bearing journals gave a natural frequency of vibration that coincided with 6,600 & 3,300 RPM, any prolonged full throttle running at 6,600 rpm soon broke the crank adjacent to the rod bearing journal.

A member in the Group Research dept. gave this matter some thought and came up with the answer - a better finish in the fillet radius each side of the big end journal. In production the journal radius was done by the same grinding wheel that ground the journal, this meant that tiny microscopic scratches were left and this is where the fatigue fractures invariably started. His solution was to roll under high pressure a ball around each journal, leaving a perfectly smooth finish.

The layout of the Test shop.There were five Heenan &Froude hydraulic dynamometers and one electric dyno, an elaborate set up ideal for research work. The electric dyno could be reversed to drive the engine you were testing. Everyone was half scared of it, except Arthur Bridgewood, he used it a lot. He insisted that there was always an apprentice standing with his hand on the big knife switch to cut it off dead, if an engine blew up whilst running, current would continue to flow rotating the already damaged engine to destruction. The operator had to be wide awake and act quickly if something broke or seized. We eventually traded this dyno to Research for a nearly new DPX1. The other dynos were two DPX2, one DPX0 and two DPX1. When the MC1 came into the shop we had a new high speed dyno- a DPX3 .

Originally all the dynos were driven by chain from the engine sprocket, a very inefficient method, but simple. We used a 2:1 ratio to keep things simple. Anyone who favours primary chain drive should attend a test using chain drive. At about 6000 RPM take a reading, then get a squirt oil can and oil the chain, the engine will pick up an apparent 2bhp.

Heenan used to recommend a shaft and two universal joints like in a car, but we found them unreliable, the universal joints used to break up and fly all over the shop like shrapnel. We eventually went to a bonded rubber coupling which if lined up carefully gave good results. All the dynamometers were arranged in a line with their axis parallel, very neat, but very impractical, as the blast of cooling air and exhaust blew from one to the next, making it impractical to use more than one engine at a time, due to blast of air and if testing a race engine the noise and fumes, to say nothing of oil.

To try to get away from these difficulties and to control the blowing oil we had some metal shields on castors made which could be rolled around behind the engines. When cooling air blowers were turned on the shields tended to move around, they soon got coated in oil and one had to avoid brushing against the oily surface. This system remained in used for some years until the shop was demolished. The development shop was once a stable, it was quite old, with over 30 foot ceiling and heated by steam pipes. In summer the only cooling was by opening ventilators.

Originally there was no provision for letting air and fumes out, so a rather expensive sheet metal ducting system was built with a 6 hp fan drawing air from just behind each engine. Cooling air was blown over each engine by a powerful 'squirrel cage' blower, giving an 80mph blast. This cooling air was ducted in from the roof and it was possible to select cold outside air or warm inside shop air by operating a flap valve in a ??? WY' joint by means of a cord. When you run an engine under full power on a dyno you have to be wide-awake, if it starts to tighten up or the exhaust note changes you shut it off immediately. If there are two engines running, it is difficult to tell which is about to falter.

There was no objection to running an engine on the shop exhaust system for 'running in' purposes, this running in was an important part of testing a new engine, it will not deliver its best power until it is 'broken in'. Once a month we would take an engine at random from the production line and after a couple of hours of gentle running, take a full power curve, if it was down for power we would strip it to find out why. Should it be badly down on power we would take another engine from the same batch and test it, if it also was bad, we had to get that particular assembly line stopped until the fault could be located and corrected. Needless to say this was an unpopular action, but was necessary to preserve (the factory's reputation.

The only time I can remember actually calling for a halt to production was on the A10 line and later on the C12. Usually what happened was a cumulative effect due to tightness, maybe a worn tool, making one part slightly oversize and a corresponding part slightly undersize. Sometimes an extra hour running on the dyno would be enough to restore the power.

All Gold Stars and Road Rockets were tested by the engine test dept after a period of running in. The cylinder heads and cylinders were removed for inspection and individual power curves issued with each engine. Some BSA production engines were always consistent and actually gave more than average power. The B31 for example always gave at least 17bhp often more. The B33 500cc standard engine was another consistent performer giving 22 - 23bhp when new. The twins were not so good, the A7 500 was better than the A10. The B 31 was a good little engine, a 350cc single, with cast iron head and cylinder. By fitting a few Gold Star parts they were easy to improve. By merely fitting Gold Star cams (touring version) and a Gold Star silencer they would put out 23bhp. By going a little further, fitting eccentric rocker spindles, lighter push rods and tappets, shorter connecting rod, shorten cylinder to suit, Gold Star piston giving 8:1 compression in place of 6.5:1 they would give 27bhp and almost 100mph at no extra cost since these were all production parts. The B33 500 was much the same and could easily give over 30bhp.

Ariel used a BSA A10 in their Huntmaster and one day they complained of lack of power from these engines. I requested them to send me a 'bad' engine and I would test it on our dyno. Sure enough it gave only 27bhp. So we stripped it to see if there were any obvious faults, then gave it another 1 hours running and it was a little better. I noticed that they were using Ariel exhaust pipes and silencers which were different from the A10, larger diameter and slightly shorter and different silencers. We fitted standard BSA pipes and silencers and immediately got 31bhp by fitting one size larger main jet the power was just under 33bhp. We informed Ariel with what we had done but they did not seem keen to change things. Perhaps they liked the appearance of the larger diameter pipes.