Vintage postbag, January 1963

De Dion Controls


I hope you will forgive a letter which will appear to be niggling about unimportant trifles, but in your account of your trip. to Brighton in Montagu’s de Dion Bouton I see you have fallen into the same trap as Karslake and many others. The pedal which puts on the transmission brake does not also put the engine on half compression (unless Montagu’s specimen has been altered, and I do not think it has), but reduces the degree of lift of the exhaust valve. Therefore, in conjunction with the automatic inlet valve, this device served to throttle the engine—rather ineffectually by our standards I agree, but that is what it was supposed to do—and the hand control you referredto as a throttle was, in fact, a mixture strength control.

If the adjustment is correct the action of the decelerator and brake should not be simultaneous, but the first-half travel of the pedal should work the decelerator part of the business and only after the valve lift has reached its minimum point should the transmission brake begin to bite. If in proper order this brake is adequate to stop the car, but as it is very small and heats up quickly it is best to use the side brakes as much as possible. However, for a quick stop, as designed by the maker and if properly adjusted, the footbrake/decelerator brings the car to a halt unaided thereby leaving the hands free to bring the clutch/gear lever to neutral whilst still retaining command of the steering and even, with a bit of practice, to flick the air and spark controls about if necessary.

If you open the bonnet of an early de Dion and get someone to work the control you will see the valve tappet clearance increases from about a sixteenth to something over a quarter inch: when de Dion gave up their variable lift exhaust and automatic inlet they continued with the decelerator-cum-brake pedal for many years by linking it to a normal throttle valve—normal, that is, except that it was arranged to open with the pedal up and close with the pedal half way down; remainder of the pedal travel then applied the brake as on the earlier type. This provided a very easy and logical system of control; there was, of course, an overriding hand control for tick-over. Most people disliked the decelerator because they had already become accustomed to the more common accelerator but those who took the trouble to come to terms with it found it admirable, and had it got in ahead of the more usual system I am sure we should have had 2-pedal cars fifty years earlier. We still have people blaming their accidents on pushing the wrong pedal in emergency but with the Edwardian de Dion 2-pedal arrangement—(decelerator and clutch) the instinctive panic action of pressing down with both feet could not do any harm.

I have been enjoying the Minervas. I wonder whether the Desoutters know what has happened to the superb Minerva old man Desoutter had in the ‘twenties. I believe he had a Lanchester 40 as well but I always envied the Desoutter who was at school with me when he rolled away in the Minerva.

I apologise again for my niggle—but I have such a high regard for the early de Dions and their ingenious controls.





Following your article about the days of early motoring, in which vou reproduce an article written for the Bystander in 1905 by my brother Alfred Hunter, I am wondering whether one of our experiences during those pioneering days might be deemed interesting.

Round about the year 1906 my father had a house about halfway up Whitehill, Henley-on-Thames, a steepish hill which was, in those days of motoring only climbed without a stop by the very few. The others could all be relied upon to come to a laboured stop outside the drive to our house. Consequently, my brother and I used often to take up our positions in comfortable chaiselongues at this point, to observe the fun, lend what assistance we could, commiserate with the drivers and ply them with liquid refreshment, those being the days of real motoring bonhomie.

One day a Gobron-Brillie came to a halt in the usual spot, the exasperated driver got out and said, “Now, boys, this car cost rue £1,000—you can have it for £60.” After a hurried consultation with father, we joyfully accepted the Offer. We ran this car for a while and soon discovered that we had to spend more time under it than in it and learnt to carry a special rug for lying on during these frequent incidents. Eventually we advertised it for sale without success until my imagination fired me into describing it as “a motor fit for a nobleman,” when we sold it at once (not to a nobleman!) and bought a 2-cylinder Renault which gave us some happy hours.

It seems somewhat sad to reflect that in these days of comparatively trouble-free motoring, and without quite the old uninhibited camaraderie, such innocent fun and unexpected incidents are things of the past, as even the smallest car made today will probably hum up Whitehill at a steady and uninterrupted 40 m.p.h.!

Kensington, W.8. EDWARD W. HUNTER.


Letter to a White Elephant

Dear Fellow Elephant,

I admired your picture in Motor Sport (V16 Cadillac) and I was most interested its your theory that those “things” (Mini Minors) are motor cars. As you know, the “thing’s” roof hardly reaches our bonnets. Where could it possibly have an engine ? I think they must be some form of cyclecar.


P.S. Does Mr. Boddy know that your great grandfather, back. in ’03, had a sealed radiator and reservoir tank?


Thoughts About “Classics”


I read with particular interest your “White Elephantitis” article on the V16 Cadillac, and cannot restrain myself from some comments, on this marque, having a 1933 770 Series V12.

First, there are plenty of enthusiasts who would dispute the Statement : “. . . Cadillac, without dispute America’s best car . . .” Second, I believe that the V16 preceded the V12, by one or two years.

Aside from these points, I have no criticisms to make of your very thorough summary, which brought back memories. The V12 and V16 have a nearly identical cross-section; the 12 having 3.125 in. bore against the 3 in. of the 16 (equal stroke at 4 in.) giving the 12 about 6 litres. Both engines do with less main bearings than crankpins; five mains on the 16, four on the 12. Connecting-reds for opposed cylinders are side by side on the crankpin, the banks being staggered. I don’t remember dimensions, but the bearing diameters are quite large, and journals and crankpins kept relatively short. The rods are drilled for wristpin (pardon, gudgeon) lubrication. My engine, at least, had 4-ring pistons, and Cadillac supplied new ones in aluminium for a much needed rebuild. (I opened the engine expecting to “decoke” and found it to be extremely loose. I have since found this a common ” complaint ” with American ” classic ” owners, that the big engines keep pulling amazingly well after long use, and they don’t start rattling until the clearances get very loose. Maybe it is just the smooth cacaphony of multiple clacks of much machinery at relatively light loading that fools one!). The hydraulic valve lash silencers work on eccentric bushes in the rocker arms; with, as you indicate, normal adjustment screws on the rockers. The cam followers are roller type. My V12 had constant vacuum Detroit lubricator carburetters, with a double trap-door arrangement in the throat; vacuum lifting the doors, which in turn lifted the main jet needles.

It is interesting to note that Cadillac deemed it unnecessary to widen the “V” in the design of the 12; both the V16 and V12 have 45 degrees between banks. The contemporary Dykes Automobile Encyclopedia went so far as to graphically illustrate the out-of-cadence firing in this 45-degree V12, and showed that, with 6-cylinders firing on every turn Of the crank, this 15 degrees from perfection was insignificant. Surely the manifolding was facilitated, in being outside the “V.” Though it was left to Marmon to take full advantage of the o.h.v. “V” design, with intake plumbing inside, and exhaust outside, on their V16 and one V12. (A backbone, 4-wheel independent design, which was only executed in one known Pilot model.) Indeed, the Cadillac V12 was remarkably smooth, and with a fine multiple disc clutch I illustrated this more than once by pulling the 5,200 lb. from rest to motion in top cog.

I have no idea of the machine’s potential top speed. I took it up to about 85 once before the rebuild, but tire out-of-balance then ‘tared an ugly head. Cornering was remarkable, bearing in mind the wheelbase and weight of the 7-passenger saloon; steering very precise, and fast. As for “America’s best” (the Duesenberg has been ably defended by others), there are of course a number to consider. Undoubtedly among them are the V12 Packard, and the less-known Lincoln KB series, a remarkable V12. This engine, though side-valve, was extremely well designed and executed. It incorporated fork and blade connecting rods, opposing cylinders in the same plane, with a magnificent 7-main-bearing crankshaft; fully machined, fully counterweighted. (With removable weights, required in assembly-disassembly.) The lower end in this 8-litre V12 must be seen to be believed. The crankcase is an insignificant example of aluminium casting skill, rising up around the cylinders in the same manner as the Cadillac design. And the s.o.h.c.,and d.o.h.c. 32 valve, Stutz “Eights” are not to be neglected in any contest among America’s best.'”

In closing, I would say that Cadillac reached a design-execution zenith in the V12 and V16, within the “classic” definition of the automobile, (“Classic” is an evasive term in automobiles, better clarified by citing good examples than in any black letter definition.) There is no point in trying to rake in their contemporary output, as this is an entirely different, and for many of us a far less satisfying, milieu of luxury automobile design.

I have switched from “heavy” to “light,” and at present own a T.T. Replica Frazer Nash, which is a philosophy unto itself! Many thanks for writing the most interesting motoring journal to be had.


Test Comment


Is it not time that legislation was introduced to enforce the compulsory testing of one-year-old Ministers of Transport?

Rothbury. P. L. HANSON-LESTER.