Interest in the Alvis “12/50” has never been greater than at present, and has prompted me to write regarding my own model, the performance of which, in its original form of “big-port” 2-seater and subsequently as a single-seater “special,” may be of interest to Alvis fans.
My car was a 1928 beetle-backed 2-seater (SD series), and when I got it in 1934 had been through a number of hands. It was in quite good condition, however, the engine having been sleeved shortly before I got it. All the ports were beautifully polished and there was an outside exhaust system. Con. rods were the dural type, with fully floating gudgeons in h.c. solid-skirt pistons, and I am inclined to think that the crankshaft was rather special, as the standard crankshaft timing wheel would not fit it, the centre having to be turned out to suit. Perhaps some Alvis enthusiast can enlighten me on this point. The sump appears to have been fitted with an extra oiling system at some time, and it is alleged that the car was raced at Boulogne by the late Major Harvey, but I cannot confirm this. The axle ratio was 4.3 : 1, giving a speed of 84 m.p.h. at 4,000 r.p.m. in touring trim, although the engine would run up to 4,500 without signs of distress, and I have had over 90 m.p.h. while competing at Phoenix Park, Dublin. I found Champion R1’s suitable for either touring or speed work. They seldom, if ever, oiled or sooted. There was a compression plate for the base of the cylinder block, but I never used it. Pinking occurred when running on plain No. 1, but the addition of 25 per cent. benzole or use of Ethyl cured this. Brakes were very good, the shoes being rather broader than I have seen on other 12/50s.
I ran the car in most of the local trials during 1934-35, and despite the high axle ratio, did quite well. I also entered for Craigantlet Hill Climb, but beyond hitting the bank well and truly (due to a broken accelerator return spring), did nothing spectacular in this event. I then decided that an alloy clutch housing and a Hardy-Spicer propeller shaft would be a “good thing” for performance generally, and when in London late in 1935 made enquiries regarding these. I had almost given up hope when, quite by accident, I met George Foxlee, and, after a short chat, knew that my search had ended. At that time Foxlee’s works were out at Letchworth, and he took me there in a very modern (at that time) Frazer-Nash, which was a real thrill for me, as I had never been in a Nash before.
Needless to say, Foxlee was a mine of information about 12/50s, and his own special competition job was just about completed. Its details are now well known to most Alvis fans. From him I obtained the alloy clutch housing (which reduced flywheel weight by 18 lb.), the Spicer shaft (converted ex-Essex) and double capacity oil pump, all of which helped to make my 12/50 a really potent job. So much so that I got two “thirds” at Craigantlet in 1936, and got in some rapid laps at Phoenix Park Handicap (averaging just under 70) before breaking a rod, which convinced me that a rev. counter was there for a purpose! As the rod was dural, no other damage was done, beyond breaking the piston. Next year the car ran at Cork, finishing fifth in the handicap in the hands of J. D. McClure.
The light aluminium bodywork was now getting rather shabby, due to rough usage in trials. So shabby, in fact, that the I.M.R.C. refused to accept the Alvis for the 1938 handicap event! I had already decided that the engine was giving its best, and the only way to obtain more performance was lower weight and higher gearing. I looked around for something I could swap the engine into in a hurry, as I still wanted to enter a car for the Park event, which was being run in a few weeks’ time. The only thing I could find was a Sullivan special, and, after some measuring and debating, it was decided that the Alvis engine could be fitted in it fairly easily. For the benefit of those who never heard of Sullivan specials I had better explain that it was a local product consisting of 1932 side-valve Morris Minor engine, linered down to 746 c.c. with special crankshaft, rods, pistons and valves, and blown by a No. 8 Powerplus driven off front of the crankshaft. This was coupled to a Wilson pre-selector racing box, chassis, axles and steering being Morris Minor, with hydraulic brakes. A neat single-seater body, with streamline tail incorporating petrol tank, was fitted. This particular car was driven in various Irish events by the late Trevor McCalla, but I don’t think it was ever placed, owing to various petty engine troubles.
I knew, of course, that it was a bit of a gamble fitting a 12-h.p. engine in such a light chassis, but I had great faith in the Alvis engine, and it had always been my ambition to put it in a chassis that would give it a chance to show its paces, pulling a high top gear. As things turned out the risk was justified.
A small sub-frame was built and the Alvis engine mounted on this with the usual rubber washers. It was connected to the Wilson box by a flexible coupling, and, as no clutch was necessary, the Alvis flywheel was reduced to about the size of a large dinner-plate, despite gloomy prophecies as to what would happen when the engine was started! The Alvis radiator was mounted well out on the dumb-irons, slightly inclined, and the outside exhaust system was also retained. The steering was the biggest problem, as the Alvis engine mounting prevented the use of the original Morris lay-out. Several steering boxes were tried without success, most of them being too big for the space available. Comic relief was provided by the fact that one box (off a Rally, I think), which seemed to be just right, when fitted was found to turn the wheels to the left when the steering-wheel was turned right (and vice versa). Although it was pointed out that this would make the car practically thief proof, it was felt that the disadvantages of such a system were many, and the box had to come out!. Eventually, a Chevrolet steering-box was used (being small and fairly high-geared), the column being shortened to suit and fitted with a spring wheel. The axle ratio was the next difficulty, as this was much too low-geared for the new engine (4.8 : 1 with 4.00″ x 19″ wheels). There was no time to get a crown wheel and pinion made, so wheels off a “T”-type M.G. and tyres off my own Talbot “90” (5.50″ X 19″) were fitted, but even then the car was very much under-geared, maximum speed being about 85 m.p.h. at safe revs. As the complete car weighed under 10 cvvt. the acceleration was rather startling, while despite the pessimistic prophecies, the engine would tick over perfectly, due, no doubt, to the well balanced crankshaft and drums in the Wilson box acting as flywheels.
The whole job was completed in little over a week, involving much night work and assistance from enthusiastic friends. The car ran at Phoenix Park after all, being entered as a “Himmelwagen,” partly to disguise its origin, and partly as a joke! Although it had never been tried out on the road except for the run to Dublin, it ran and handled remarkably well, lapping at an average of 71 m.p.h., and had it not been delayed by a pit stop (due to a broken tappet adjuster) it would have finished well up the list.
During the winter of 1938 I had a crown wheel and pinion made, which gave a ratio of 3.6 : 1 allowing 4.50″ x 19″ tyres to be used. This gave a speed of approximately 94 m.p.h. at 4,000 r.p.m., well within the safe rev. limit, while acceleration was still very good. Over 70 m.p.h. was possible in third gear. I ran the car at Donabate Speed Trials early in 1939, and was quite satisfied with its performance there although for sprint work a slightly lower axle would have helped. On the way down from Belfast, however, I had over 4,000 r.p.m. on several stretches of road, representing speeds of almost 100 m.p.h. The rapid acceleration and high cruising speed, combined with low revs., made it a most fascinating road car, despite the rather hard suspension. All the springs were bound with whipcord when I got the special, with Hartfords all round, transversely at the rear. I removed the binding from the rear springs, as I considered the springing was too hard and was causing wheel spin.
Nothing further was done to the car, and I entered it for the Leinster Trophy race, which was held in July, 1939. For personal reasons I was unable to drive in the race myself, although I got in some laps during the practice, and the car was handled by C. E. Robb, better known for his exploits in Irish races with a J4 M.G. Midget. Despite bad weather and the fact that he had never driven the car before, he finished in first place, tying with another competitor for second fastest time of the day, as well as winning the 1,500 c.c. class. His best lap, on a very tricky circuit, was at an average of approximately 68 m.p.h.
The outbreak of war put an end to any further activities, but the “special” is carefully stored away in a dry garage, and I am working on the engine with a view to happy days ahead.
Some time before the Alvis ceased to exist as a “beetle-back” I bought a 1931 Talbot “90”, with Van den Plas open 4-seater body. This was a grand fast touring job, the turbine-like engine being a marked contrast to the “punch” of the Alvis. After I had the engine sleeved and crank ground I covered many thousands of trouble-free miles all over Ireland, and was really sorry to part with it early in 1942, but I needed the garage space. Unfortunately, the new owner had it only a few months when he was killed while motor-cycling to Londonderry to see some motoring enthusiasts who were stationed there.
With a view to post-war motoring, I have just purchased a 1930 4.5-litre Bentley. with open Van den Plas body. I would like to get in touch with previous owners of this car (registration book is a duplicate), registration number being GC 6645, engine number AD 3653, as I know very little about Bentleys and their habits. General condition of the car is good, and from the short run I had in it before deciding to take it, the engine appears to be all that it should be. The fact that thick, black gear oil had been put in the gearbox made the changes rather sticky, and I am inclined to think that engine oil should be used here, and possibly in the axle, too, as I seem to have read somewhere that one grade of oil does engine, gearbox and axle. No rev. counter is fitted, but I understand drive for one can be taken from the front of the camshaft. There are large Zeiss headlamps with mirror reflectors, one of which appears to have been removed to conform with early blackout regulations. I am at present fitting tele-control shockers to the front end, in place of the rather odd-looking Hartfords (they have friction discs at three points) which are fitted all round. If any Bentley enthusiasts in Ulster should read this, I would be glad to hear from them with a view to having a chat and getting some “dope” on the car generally.
My present motoring is confined to business trips in a Ford “Prefect” saloon and Home Guard D.R. duties on a 500-c.c. Matchless “Clubman” model at the week-ends, but the war can’t last for ever, so let’s hope the “good old days” are not too far away.
I am, Yours etc., .
C. S. Porter. – 20a, Chichester Avenue, Belfast.