MY I-I-LITRE TARGA-FLORIO MERCEDES-BENZ
By C. W. P. HAMPTON I purchased this Mere( 41 s-Benz from J. H. Bartlett for 00 in November 1935 and found that mechanically it was in poor condition. (Incidentally, Bartlett told me that he thought it needed an overhaul as the previous owner had dismantled it and reassembled it himself and “there’s a mass of mechanism when it is in pieces and it needs an expert to put it back reliably.”) The rear axle hummed excessively, especially when turning to the left, which suggested something wrong ; the E.N.V. self-change gearbox slipped in first and reverse gears ; the brakes literally hardly worked at all, and the engine sounded rather loose and suggestive of big-end trouble, though It ran satisfactorily up to about 70 m.p.h. The carburation, however, worked well and the ” blower ” could be held in without spitting back but by means of a ” Heath Robinson” arrangement of floats, pipes, tanks, taps, etc., made of odd bits and looking most untidy. On being dismantled, the engine was found to be in an appalling state—the connecting rods were out of balance, one piston was odd, the valve guides, cylinder bores, pistons and timing wheels were badly worn, the bearings very loose with practically no white metal, and the oilways broken and choked with dirt, sludge and odd bits of metal. The electrical wiring was faulty and antiquated, as also were most of the com
ponent parts. The Corsica two-seater body, painted red with black flared wings, was in shabby and uncomfortable condition. As to the car’s history, I know little. Apparently only six of this type were ever made and two were entered for the Targa Florio race in 1922, being driven by Minoia—who retired with ignition trouble—and Scheef, who finished twentieth. This appears to be the date of their construction, as mine has August 1922 stamped on the crankshaft. Of their subsequent racing history I know nothing, except that mine, and one other of the six that were constructed, were sold to Mr. Raymond Mays about 1926/27. I know little of my car’s history since, except that it was first registered in England on November 22nd, 1928;
In this article Mr. Hampton describes in his own words his fascinating little Merckles-Benz, which has of late been attracting great attention whenever it has appeared in public. The car has puzzled many people including, we believe, Hugh McConnell himself, for its present appearance belies its fifteen summers It is actually a 1922 1f-litre sixteen-valve twin camshaft four-cylinder job with the usual Mercedes blower system and an E.N.V. gearbox. It ran in the recent Vintage S.C.C. Chilterns Trial, and the J.C.C. Brooklands Rally on February 27th. About ten years ago Raymond Mays owned two of these cars, one of them subsequently passing into the hands of the Hon. Dorothy Paget, who stabled it at Thomson & Taylor’s— the car was illustrated in MOTOR SPORT in March 1931. These cars must not be confused with the 2-litre and 11-litre eight-cylinder Mercedes cars that Mays drove in sprint events in 1927. There follows quite a wealth of detail about this extremely individualistic, ” pur sang” motor-car, from the pen of its present owner, who, incidentally, is on the Council and Competitions Committee of the Bugatti Owners’ Club and is the owner of a Type 55 and a Type 49 Bugatti.—Ed.
probably when Mays disposed of it. The Hon. Jock Leith had it for a time and found it satisfactory except for a complete absence of brakes and perpetual carburation trouble when using the “blower.” Then a Captain Pane bought it and fitted the E.N.V. gearbox and made other modifications, principally to the supercharger system, which he managed to improve, but by means of the aforementioned complicated and untidy layout. He, too, found the brakes an apparently unsurmountable difficulty in that any attempt to produce braking on the front wheels twisted the dumbirons and front axle, causing the car to swerve violently.
The whole engine and. all component parts are most beautifully made and an absolute model of metallurgy and design —considering four wheel brakes (admittedly practically inoperative), double overhead camshafts, supercharger, etc., in 1922! The bore was originally 63 ram. and R.A.C. rating 9.8 h.p. It is now 65 mm. with a stroke of 112./5 m.m., giving a cubic capacity of 1,496.5 c.c. and R.A.C. rating of 10.4 h.p. The compression ratio is nearly 7 to 1, which is high when supercharging at 8 lb. per square inch. Incidentally. I believe this model is rather apt to throw connecting rods and, when dismantled, it was evident that trouble had been experienced previously in this direction, so that I am determined not to over-rev., to try and prevent a blowup which would obviously be expensive in view of the limitation of spare parts and the money already spent in getting everything O.K. The low oil pressure of about 8 lb. at 2,000 r.p.m. and 16 lb. at 4,000 r.p.m. (when warm) does not help in this direction, but appears to be sufficient. Maximum safe revs. are 4,500/5,000. It needs practically no oil, using Price’s ” C ” de luxe. I use Cleveland Discol petrol, but have no idea of the consumption—probably about 10 m.p.g. at the moment, as I think the main jet in the old Claudel-Hobson aero-type carburetter is larger than necessary. The honeycomb radiator does not leak and the water (circulation by pump) runs very cool normally, except in traffic, when it overheats, as no fan is fitted. The oil runs at the same temperature as the water and I am contemplating the fitting of an oil cooler. These cars originally had two axle ratios, but I have only the higher of the two, viz., 4 to 1 on top, giving 19f m.p.h. per 1,000 r.p.m. on that gear. The gearbox is fairly closeratio, except bottom, which seems rather low, probably about 14 to 1. There were two “blowers,” but I only have the smaller of the two, though I tried to fit a 86/220 S. type “blower,” but there was no room. The ” blower ” was O.K. for conditions. Lubrication is from the engine to the ” blower ” clutch and also by means of a screw-down type grease
gun which I have had fitted on the central gear-quadrant, giving a turn or so every so often according to how much I use the supercharger.
Now for what I have had done. Soon after I bought the Mere. I took it to Messrs. West & Chittenden, Ltd,, Sutherland Street, 1,Valworth Road, who have been responsible for all the mechanical overhauls and have worked excellently, though taking many months over it. They completely stripped the engine ; rebored the cylinders which are separate steel castings with the water jackets welded around. Martlett pistons were fitted at normal sports-car clearances. The crankshaft was reground and the oilways cleaned and repaired where
necessary. They made up new brass valve guides and replaced the original valves (sixteen of them, filled with mercury for cooling purposes) as being O.K. They took up wear or made up new parts wherever necessary. The twin overhead camshafts are amazingly light, as also the flywheel which really comprises only a self-starter ring. The crankshaft is beautifully made with three large bearings which were, of course, rewhite-metalled and fitted with new bushes. The gearbox was returned to E.N.V. who said it was a very early type and always liable to give trouble, so I had a new or service one fitted which is most satisfactory and absolutely makes the car, as the original crash-type was, I believe, heavy and slow to shift. The rear axle was dismantled and found to be out of line, so was reground and re fitted with new races, etc. It is fitted with two crown wheels which were in
good condition, and it is a most substantial affair. It is quieter now, though still hums at high speed, being of the straight bevel type. The axle halfshafts were O.K., but new Hardy universals were fitted. The magneto (an eight cylinder Bosch converted to a fourcylinder) and dynamo were sent away for overhaul and refitted, also a new 12-volt 70 amp. Young accumulator. The car is, however, difficult to start and even
this battery is insufficient ; so I am having two 6-volt batteries of even greater amperage fitted each side of the rear axle, lower in. the frame than the present one and therefore more accessible. I then took the car to Newns, the coachbuilders of Thames Ditton, and had a lightweight two-seater sports body made entirely to my own design, which endeavoured to depart from the usual trend of two spare wheels hung on a large rear petrol tank ! The body is made of light aluminium on duralumium framing and is fitted with a flat underpart from the engine to the back axle to aid streamlining. The existing 12-gallon M.G.-type petrol tank was removed forward to just behind the seat squab but under the body. panelling, with battery, jack and rubber inset chromium tool-kit behind that. The two spare wheels were shed with Dunlop competition covers of 17″ x 5.50″. There is a detachable hood kept beneath the seat, which is of the single seat and single squab type, fitted air cushions and
covered in blue leather. A new dashboard was made painted to match, with centre polished aluminium panel incorporating the following new instruments : Jaeger 5 in speedometer, 5 in. rev, counter and clock, oil thermometer, water thermometer, oil pressure gauge, supercharger gauge and amp. meter. Also on the dash is the new Scintilla switch-box, Ki-gass starter and Westric charger socket. There is a fold-flat windscreen fitted two chromium Bosch screen wipers. An extra long and well-louvred bonnet and light cycle type wings were made.
Scintilla stop and tail lamp and Scintilla headlamps were taken from my Type 55 Bugatti when I fitted Marchal ” Strilux ” to the latter car. Lucas dual tone trumpet horns are mounted on the front and an electric bell on the side! I had an outside chromium-plated exhaust system made, protruding through the bonnet with large flexible pipes (on similar lines to that of the “38/250 ”) and leading into a chromium Burgess silencer, with 13 in. fishtail at the back. The whole looks very effective, though it is not particularly quiet when the ” gasworks ” are opened !
I had the wheels chromium-plated and fitted with new spokes by Messrs. India Tyre and Rubber Co., Ltd., who did the job at reasonable cost and of the most excellent quality. The faiur road wheels are fitted with India 13″ x 4.5′ tyres.
India’s also rebuilt one wheel to take a x 5.50″ tyre and made a new wheel to match—both chromium-plated.
The rest of the car is finished in. opalescent blue and really looks very modern and smart, though the seating position is rather high, due to the chassis, which is now low judged by modern standards. Rear suspension is Cantilever, with semielliptics in front. Large Duplex Hartford shock-absorbers are fitted and I am going to have these converted to Telecontrols. New Rudge hub cabs are fitted ; the radiator and all possible parts such as steering box and column, induction manifold, oil and petrol pipes, etc., are chromium-plated, and the steering column lengthened and fitted with an Ashby wheel.
From Newns, I took the car to Messrs. L. G. Bachelier & Sons, Ltd., of Durnsford Road, Wimbledon, who did the rewiring throughout and made an excellent job of it in Continental cable, giving a typical ” Bach” finish to everything. They also raised the rear wings at a later date and fitted a twiiS.T.T. petrol pump. I then ran the car for about 800 miles, not exceeding 45 m.p.h., except for a burst Of speed at BroOklands after 050 miles (when we first saw the car—Ed.), and returned it to West & Chittenden just before Christmas for carburation attention. This is now much simplified, by a pressure system to a large float chamber on the dash and also direct to the carburetter ; pressure being from the ” blower.” It is satisfactory over about
3,000 r.p.m. They also tackled the brake problem in the summer. This was overcome at great difficulty by fitting Lockheed hydraulic system from a Morris Six. The drums were riveted on to the Mere. face and relined. A Riley ” Nine” front axle was used as the Merc. axle was too weak. The Mere. ” knock-on” hubs were fitted in place of the Riley ” bolt-on,” but as space was strictly limited the Morris drums on the front were narrowed down and Triumph Lockheed cylinders fitted—there being no room for the laiger Morris cylinders I All very complicated, but a masterpiece of ingenuity, patience and workmanship. Radius rods were fitted to the front spring anchorages (which were, of course, specially made up to fit the Mere. springs on the Riley axle) to hold the axle in place under braking stresses and a tie bar fitted between the dumbirons (which are of great length, the radiator being set well back in usual Mere. fashion) to prevent chassis twist. Originally, the most forward member was under the radiator and this was tracked when I bought the car. The original brakes were quite hopeless, the drums inadequate and the leverages all wrong, but now the brakes are very good indeed, though probably not as good as those of many modern cars.. The outside handbrake is quite hopeless, being on the transmission and renders starting: on a steep hill difficult, as it entails use of footbrake and hand throttle. West & Chittenden fitted a fly-off lever off an old Lancia ” Lambda,” which is
much neater than the original cumbersome affair.
The car has now done just over 1,000 miles and I intend entering for certain trials, etc., as it should do quite well when fully run in and when the carburation is further improved.
I have so far had nearly 4,500 r.p.m. (about $5 m.p.h.) on top—still accelerating. The maxima on second and third are about 35 to 40 and 60 to 65 m.p.h. without over-revving. Probably a higher gear ratio will be necessary as the performance is turning out to be better than I had hoped.
On the recent Vintage Sports Car Club Chilterns Thal, it showed to have lashings of power on hills, failing on Widmere through wheelspin, and held 70 to 75 on the Oxford road with apparent ease, the ” blower” giving the usual exhilarating siren-scream when cut in. I have used Champion ” 13″ plugs, but these are apt to burn up and I am now using X.L.G.s. They seem to stand up to revs:, such as can be used on the road, yet do not oil up when left idling
at about 1,000 r.p.m. In other words, I have experienced no plug trouble.
-Thus, I have a unique car which causes immense amusement and fun and, though fifteen years old, can equal most sportscars of similar horsepower and is highly individual, fast and ” pur sang” to the highest degree. For obvious reasons, I am being careful to avoid a ” blow-up,” as by its willingness to rev, this might easily happen if the rev, counter were disregarded.