The Bamford & Martin Astons
Some notes by F. W. Ellis
The earlier Aston-Martin cars, made by Messrs. Bamford & Martin, Ltd., of London, under Lionel Martin's supervision, before the present company came into being at Feltharn to build cars to Bertelli's designs, are now amongst the rarer of the vintage sports cars. Nevertheless, they still arouse much interest, and are of such exclusive design that we have no hesitation in publishing these notes about them, by that very staunch supporter of the type, F. W. Ellis. His remarks qualify an article which appeared in Motor Sport of April, 1938, and will doubtless set many enthusiasts hopefully searching for remaining examples of this unique and desirable British 1.5-litre. Mr. Ellis is anxious after the war to form a club for owners of what he enthusiastically terms the "real" Astons, and he suggests that a move be made now to get such owners together. He personally knows of fourteen cars still in existence. These comprise ten side-valve cars and four twin-o.h.c. cars as follows: Ellis's own two cars, Johnson-Ferguson's famous 2-seater, G. R. Brook's car up in Huddersfield, the ex-Forbes car, which was mainly the subject of the above-mentioned article and is now owned by F/O. Anthony Phelps, a side-valve owned by D. B. Tubbs, two such cars being rebuilt by Grosscurth, at Maidenhead; Farmer's Anzani-engined car, Romero's 3-seater, Tubbs's twin o.h.c car "Razor Blade", the ex-Morris Goodall twin-cam 2-seater which Ellis has bought and the immortal "Bunny", now believed to be in Scotland and to have wire wheels, a Sunbeam back axle and probably a twin o.h.c. engine. In addition, we believe the car run by G. P. Green (XP 311) to be still in existence and a few others probably survive. Will those interested in the club or in these cars please write to Mr. Ellis at 11, Christleton Avenue, Heaton Chapel, Stockport. These cars were beautifully made and represented the first effort to make a car in this country which was of the same capacity as the 16-valve Bugatti and would yet stand no nonsense from it. Consequently, these notes should be of interest both to those who are rebuilding examples of these cars and to those who merely wish to learn more of Lionel Martin's outstanding production.---Ed.
I have spent many pleasant and enjoyable hours reading and re-reading the "Cars I Have owned" series, and it seems quite queer to me that so many people who have owned such a wide variety of cars seem to have missed owning specimens of the famous side-valve Aston-Martin. The Bamford & Martin Aston is one of the most exclusive of all the vintage cars and I cannot help but think that many enthusiasts have missed something in motoring which very few cars can give. Therefore, these notes may prove or interest and help prospective and present owners of the type. Also, may I be forgiven for having a one track mind where these cars are concerned. as in all my experience of cars, amid it is a fairly wide one, I have yet, to find a more satisfactory and pleasant piece of machinery to handle?
The history of the s.v. Aston-Martin has been dealt with very fully in past issues of Motor Sport and, therefore, it seems hardly necessary to dwell on this, but I do hope that when all my data are collected I shall be able to write a very full account of the history and achievements of these cars.
I first became Aston-Martin-minded in 1922, when the twin oh. camshaft Grand Prix cars were produced, and although quite a small boy at the time, my mind was made up, and from time to time I used to build scale models of these cars; no doubt very crude, but they gave me no end of pleasure. In this state I first made the acquaintance of Lionel Martin. I found him most interested and helpful and he sent me some very fine photographs and catalogues, etc., which are still among my treasured collection.
In 1926 a very fine 3-seater appeared for sale in Coventry, For the sum of £260, and my father had been almost persuaded to buy, when the General Strike came and squashed all hopes for the time being. Sundry cars came along in the meantime and in 1936 I bought my first Aston-Martin. This car which I still have, was a clover-leaf 3-seater on the standard 8' 9" side-valve chassis, with large radiator and cyele-type wings off a T.T. Lea Francis. To keep this car company I bought another s.v. Aston in 1940: this time a close-coupled 4-seater with normal wings and the same chassis as the 3-seater. About the same time I paid a deposit on the ex-Morris Goodall twin o.h. camshaft, car, and I am anxiously waiting the time when I can collect this, although as it is about three-hundred miles from here, it presents quite a transport problem.
After running the 3-seater (No. 1951) for about twelve months I set about rebuilding the chassis and body. The whole job was stripped down to the bare frame, the body being completely scrapped except for the panels, which were aluminium. A small racing radiator with a built-in stone guard was acquired, and this was fitted in place of the larger type.
The aluminium bulkhead was then cut down to follow the lines of the new radiator, and when the chassis had been completed the new body took shape. This was still a 3-seater and on the same lines as before, but much narrower, with a detachable scuttle and a large bulge for the brake pedal. like the Grand Prix cars. New ash was used throughout, and the final job was upholstered in green leather, with Dunlopillo seat cushions. The detachable scuttle was found to be a great asset, as refilling the Hele-Shaw clutch was made much easier. The car was run in this form for about three years and then the body underwent another change. This time it became a 2-seater and the petrol tank was placed behind the seats and over the rear axle. The two spare wheels were then carried in a trough where the tank was originally fitted. At the end of June this year this car came off the road for the duration of the war, and it is now once again dismantled, enjoying another "birthday". The 4-seater (No. 1966) has also had the engine taken out for a rebuild, and when No. 1951 is finished again I shall go right through this car in like manner. The twin camshaft car needs some attention to the engine, so I have before me much work in my very meagre spare time.
A description of the side-valve chassis Ina' be of interest, so here goes: The engine is a 4-cylinder of 66.5 mm. x 107 mm. with fixed head. No. 1951 has been re-bored and has 20 thou. oversize pistons by Hepworth & Grandage, but I am not so sure about No. 1966, as she has Zephyr pistons, and these may prove to be the original ones fitted. The block is a very nice piece of foundry work, the ports being exceptionally smooth and of ample proportions; the inlet is circular and the exhaust square in form. The block is cored through and a copper tube inserted for the induction, the carburetter being bolted on to the off side, the mixture passing through the block via this copper tube and thence forward to a very beautifully made copper branch pipe on the near side. This obtains on No. 1951, but No. 1966 has a cast aluminium branch pipe. The valves are in the usual position and have cast-iron guides and two springs. The diameter of the valves is 1, 7/16 in. approx., and all are of uniform size and shape. Very large bronze valve caps are used and the sparking plugs are carried in the caps over the inlet valves. There is a bronze plug in the centre of each cylinder, and it is, therefore possible to use a sparking plug over the top of the piston, although I cannot say if this shows any improvement over the inlet valve position, as I have never tried it. Bronze tappet guides are used, held in position by double forked bronze claws, one claw holding down two guides. The tappets are adjusted by using three spanners. The water outlet is a three-branch copper pipe on No. 1951, but No. 1966 differs, as it has a east aluminium pipe with the name "Aston Martin" on it. The crankcase is an aluminium casting of very sturdy structure, carrying four bearer arms, with a solid web between each pair of arms. On the near side this web acts as the magneto table and on the off side carries the control levers, which are worked from the steering wheel. The crankshaft has three bearings of very ample proportions, and these are held down by 0.5-in. B.S.F. studs. The crankshaft proportions are ample, the diameter of the big-ends being 1.5-in., and detachable balance weights are fitted. The timing wheels are at the front end and are stamped so that an error when assembling is impossible, and the cams are high lift. The connecting rods are machined all over and carry bronze-backed white-metalled bearings.
The sump is very large and carries a gear-type oil pump; this is efficient, but skimming a little off the face plate after the wheels have bedded in slightly improves oil pressure greatly. In my own case 0.010 in. was taken off this plate to even matters up. The pump is driven from the camshaft by skew gears. Nine pints of oil are carried and a large gauze covers the oil. This gauze divides the sump into two compartments and it is impossible to overfill, as when the oil filler lid is open a tap is automatically opened and this gives the correct level. The oil filler itself carries a filter and pressure-line filters are carried in the near-side back bearer arm. There are three filters in all, fitting one inside the other, and these, I believe, formed the subject of a patent; it is possible to remove and clean them without disturbing the sump. All oil pipes are carried outside wherever possible and are of large diameter. The oil pressure gauge lead comes from the back of the crankcase behind the filters and the correct running pressure is 60 lb. per square inch. Water circulation is controlled by a pump which is driven from the magneto. I have arranged an oil supply from the timing wheels which attends to the needs of the water-pump rotor shaft, which is inclined to become pitted in fullness of time; after five years, however, my own shaft (which was fitted new then) is still as new.
Starter and dynamo are carried on the off side of the crankcase. Provision is made for a cooling fan, but this is not a necessary fitting. So much for the engine itself.
The clutch is of Hele Shaw manufacture and is a most excellent piece of work. I have never had trouble of any kind nor any sign of slip. It must, of course, be treated properly; that is, if the car is in regular commission, the oil level must be kept topped up. This is done by turning the engine over until one of the brass plugs is at the top, which will bring the other plugs to the sides. Remove one of these and then, when oil is poured in at the top and runs out at the side, the correct level is obtained. A special light oil was prepared for me by the Vacuum Oil Co., but a successful compromise is 50/50 engine oil and paraffin. The racing, or small, clutch has 19 plates, and I believe this unit is slightly wider and of a different shape from the standard, or large, clutch. As a general rule the large clutch was fitted to the long-chassis cars while the short-chassis cars had the racing clutch, but an exception is provided by a side-valve long-chassis car which has just come to my notice, which has the racing clutch: this car is No. 1956, owned by Mr. G. R. Booth, of Huddersfield. (It is still possible to buy plates. These are sold by Platt Brothers, of Oldham, Lancashire, who handle all Hele Shaw spares. I believe the price is 6s. and 6s. 6d., respectively, for bronze and steel plates). A clutch stop is incorporated and the drive to the gearbox is taken by laminated spring leaves.
The gearbox is a very fine, robust piece of work with an aluminium casting which has solid bearers carried right to the frame and held in place by four bolts. The layshaft is carried alongside the driving and driven shafts, thus making possible very easy examination of all the working parts. No oil filler is provided as the lid is secured by two levers which work a clip-and-locking arrangement (modern manufacturers, please note) making it possible to remove the top of the gearbox in about five seconds. It takes about as long to replace it. Roller bearings are used throughout, except for ball thrust races, and bronze housings carry the extremities. These housings being bolted to the outside of the box, give a very workmanlike appearance. The selector mechanism is on the right-hand side of the box, a large bronze housing being bolted on behind to take an aluminium tube, plentifully webbed, which carries the gate. This is adjustable for rake and has the top gear slot forward, a very desirable thing, as a flick of the lever back into third is about as pleasant a movement as you could wish for. The constant mesh wheels are, of course, at the back.
The speedometer is driven from the front of the layshaft by two open gear wheels and adjustment is provided for this shaft at the back end. At the back of the box is a large bronze housing which comes up flush with the centre cross member, inside which is the universal joint for the final drive. On the other side of the cross member is a further bronze cage which covers the ball end of the torque tube. Eight 1/4-in. B.S.F. bolts are used to couple these three units together.
The rear axle has an aluminium centre housing and bolted to this are the steel tubes which form the entire axle casing. As the rear axle is of the fully-floating type the sleeves take only the weight and the axle shafts look after the drive. At the spring ends of the axle sleeves split bronze bearings are used, which are carried in cast aluminium housings, these in turn being secured to the springs by long U-bolts. Internally, the rear axle is very sturdy. The pinion is carried on roller bearings, the whole unit being assembled into a bronze case which fits into the split halves of the differential casing. A 12/48 crown wheel and pinion are standard and the differential is of bevel type. I believe that the racing axles were solid. The axle shafts cannot be withdrawn from the axle end, the diff. and axle shafts being a complete unit when assembled. The back plates for the brakes, both front and rear, are very sturdy aluminium castings and these carry two aluminium shoes lined with Ferodo; the brake drums themselves are aluminium castings lined with cast iron. Each drum has three ribs. The mounting for the springs is extremely good as non-ferrous metals are used for the spring shackles, the spring lengths being, front, 31.5 in.; rear, 48 in. on the standard chassis, and 30 in. and 40 in., respectively, for the racing chassis. The steering is Marles and is really amazing, since on each of my Astons not a trace of wear is evident. This is really incredible when one thinks of the condition of some modern boxes after quite a short time; three-quarters of a turn of the wheel takes one from full left lock to full right lock, and while the actual steering lock does seem inadequate this does not seem to have the least effect on the cornering capabilities of the cars, in fact, the faster you go round them the better they like it. [We believe that Messrs. Bamford & Martin took very great care over assembly of these steering boxes.—Ed.]
A longer drop arm would have made all the difference and on the later of my two cars the drop arm is 1 in. longer than on the older car.
Great care has been taken with the placing of the controls. The handbrake is about 2 ft. long and consequently has plenty of purchase. The pedals are nicely spaced and the design of the accelerator is unique insomuch as it carries two arms, one on one side of the steering column which carries the foot pad, and the other on the other side of the column which attends to the links with the carburetter. All pedal foot pads are bronze. The unit which carries the pedals is adjustable on a toothed device which allows forward and backward movement. The front wheel brakes are Perrot type and are very effective; here, again, much use is made of non-ferrous metals, a point which is evidence of the care and money spent in the design and construction of these cars. The radiator is flexibly mounted on aluminium rubber-bushed brackets and is of Serck manufacture, with nickel case.
The 16-valve cars differed very little in chassis design from the standard cars; there were, however, a few points worth noting. The chassis was much shorter and the frame level slightly lower. A very neat little radiator, with built-in stone guard, was fitted and the brakes on the racing jobs were adjustable from the cockpit. They were cable-operated and the cables passed over a series of pulleys which tensioned them by the movement of a pair of hand wheels, one for front and one for rear set of brakes.
The accelerator pedal, as described above, was shaped like a horse-shoe and fitted round the steering column, which made it possible to operate it with either foot. Hand pressure was provided for the petrol feed, as against Autovac on the standard cars, and the petrol tank was carried on the chassis over the rear axle, and not between the dumb-irons as on s.v. cars.
The 16-valve engine was one of the designs of the famous M. Henri and followed Ballot practice very closely. It had a fixed head and the twin overhead camshafts were driven at the front end by a rather complicated arrangement, taking the form of a vertical shaft-drive from the front end of the crankshaft and a housing which carried a pair of bevels and three spur gears which drove the camshafts. Further down, a secondary train of gears drove the magneto, which was mounted vertically (in the early '20s it gave a fair amount of trouble, as most of the racing failures of these cars were caused through a burnt-out magneto). The valve springs and stems were enclosed in pistons working directly on the camshaft, adjustment having to be made by shims. From the same drive as for the magneto the water pump and, below that, the oil pump were driven. Most engines were of the dry-sump type, but I know of one or two which had an ordinary wet sump, the oil finer being a huge affair, I should think big enough to hold nearly half a gallon. All oil pipes are outside and therefore very easy to keep clean. The bottom half of the engine is similar to the s.v. cars, but it does differ in some details. The small racing Hele-Shaw clutch is used.
About 1925 a twin o.h. camshaft 8-valve engine appeared; this, again, was very different from the 16-valve engines.
In this case the drive to the camshafts was through a train of gears at the front end, the valves were operated in the same way as before through pistons, but the oil filter was on the carburetter side instead of the exhaust side and the magneto was on the same side as on the s.v. engine. I have a notion that one of these 8-valve engines was used in H. W. Cook's car in the 1925 200 Mile Race, but of this I am not certain. Confirmation of this would be very welcome. An engine was exhibited in a chassis at Olympia in 1923 and this is all I know of this 8-valve twin o.h.c. job. If anyone can give me any news of it I shall be most grateful, as all the data I have is a small photograph which I cut from the Light Car in 1925.
In 1921 a single o.h.c. 16-valve engine was made and apparently was intended for one of the 200 Mlle Race cars, but nothing more seems to have come of it. This engine had four valves set vertically in each cylinder and operated by rockers, removable plates in the valve chamber sides giving access to the valve gear. Otherwise, the layout followed that of the twin o.h.c. 16-valve engines, the in-line drive for the vertical magneto, water pump and oil pump being identical, and the wet-sump lubrication system incorporating a huge filter like that used on Tubbs's twin o.h.c. car.
The performance of the Bamford & Martin Astons is extremely good, but much depends on the condition in which the car is maintained. It is essentially a car for putting up high average speeds and for this quality, along with economy, I have nothing but praise. My 2-seater (No. 1951) has been reduced in weight until I think I have got it as low as is reasonable, i.e., about 12.5 to 13 cwt., and therefore the car is probably faster than most of the existing examples. A genuine 75 to 80 m.p.h. has been attained on the Blackburn road, and the car will genuinely cruise at 65 without any fuss, the engine feeling like a dynamo, but I am searching for a 3.5-to-1 final ratio when I hope to get another 10 m.p.h. The short-chassis 2-seater, in racing trim, did close on 100 m.p.h.
The maximum safe engine speed is 4,000 r.p.m., but I have heard of this being exceeded by a large margin. I feel that the 4,000 limit must be adhered to and that in their standard form these engines should not be expected to exceed this figure. As I have mentioned before, the correct oil pressure is 60 lb./ sq. in., but much depends on the internal condition of the engine and if a steady 40 lb./sq. in. can be maintained no harm will result. The engine will respond to various types of carburetters. For instance, in my own case the following have been used: Single S.U. ex-Morris Ten; Zenith; twin S.U.s large bore and 45 degree S.U. (similar but of slightly less bore than a "Red Label" 3-litre Bentley type).
The following results were obtained:-
1. Single Morris-type S.U., needle M. 8. standard jet. Maximum speed 68 to 70 m.p.h., consumption 35 to 37 m.p.g. on long runs - 30 in town.
2. 45 degree S.U., No. 8 needle. Maximum speed 78 to 80 m.p.h., consumption 32 m.p.g.- 25 to 28 in town. With M. 8 needle, consumption 41 m.p.g., but maximum speed dropped to about 60 m.p.h. and acceleration was poor. A No. 6 needle gave slightly better acceleration than No. 8, but for all-round really good performance the No. 8 is better.
3. The Zenith was not very successful as it was much too rich. It gave about 25 m.p.g. with a maximum speed of about 60 m.p.h.. and other jets could not be obtained.
4. The twin S.U's are another story as when fitted a power bulge of phenomenal dimensions was required, and, to my eve for slimmish lines, this was not satisfactory. The engine looks good and goes really well with them, however, so I may fit them to the large-radiator car.
I found it was a great advantage to cylinder wall and gudgeon pin lubrication to remove the baffles from the top half of the crankcase. This does not, materially alter oil consumption and is well worth doing. The water pump has a habit of shearing its driving key, but this is easily retractable and if good quality steel is used the trouble will not persist. I believe that valve seats were liable to crack, but here again the drop in performance does not seem of any consequence: also I believe that it was hardly worth welding. Bamford & Martins specified that double Shell heavy oil should be used for engine, gearbox and back axle. I find that any of the recognised sports oils. such as Mobiloil "D", Essolube "Racer", Castrol and Shell, give similar results, and it is definitely an advantage to use a light oil in the gearbox and rear axle as in winter thick oil takes many miles before it is warm. The clutch stop is adjustable and very rapid gear changes can be made, and in point of fact once the habit of' dispensing with the clutch altogether is acquired, much fun can be had. Gear ratios vary. The earliest ears (1921) had 13.2, 6.9, 4.87 and 3.73 to 1 on the then long chassis. "Bunny", I believe, had a bottom gear of about 9 to 1. In 1922 the following ratios were quoted: 13.2., 6.8, 4.9. 3.7 to 1, and in 1925 14.1, 7.4, 5.2 and 4.0 to 1.
No. 1951 has a bottom gear of 10.0 to 1, the other three ratios being approximately 7, 5 and and 4 to 1. but 1966; varies insomuch as bottom is about 14 to 1. The twin-cam car has top ratio of 3.5 to 1. The standard rear axle has a spiral bevel and pillion, whereas the o.h.v. cars' axles are straight-toothed.
It was once suggested in Motor Sport that, a club for Bamford & Martin Aston owners should be formed. I am all for this, and the sooner we are able to get together the better. Present-day conditions are extremely difficult, but I see no reason why we should not become better acquainted and leave the rest until happier times.
Since completing this manuscript, I have read with interest Mr. Robson's experience with an s.v. car. I rather think he has slipped up when he says 180 s.v. Astons were made, as to the best of my knowledge, the serial numbers commenced at 1900, and in the three log books which I have we get the following: Twin cam: engine No. Mark III B, chassis No. 1913, first registered 1923; 2-seater: engine No. 1951. chassis; No. 1951, first registered 1925; 4-seater: engine No. 1966, chassis 1966, first registered 1926. Since production started in 1921 and finished in 1925, it will be seen that, commencing with a serial of 1900, 66 or so cars were produced up to the end of 1925 and this includes quite a number of twin camshaft cars.