H. L. Biggs recalls interesting memories of ” Special ” Model ” T ” Fords
THE name of Henry Ford in connection with motoring sport calls to the mind of the average enthusiast in this country thoughts of modified V8s used in trials of the ” slime-storming ” variety, or possibly sonic of those ” Special ” four and eight-cylinder cars which did so well in the Swedish Winter Grands Prix. In American racing circles, however, they think of Arthur Chevrolet, who, in the early 1920’s, realising that the excellent pow er/weight ratio of the Model ” T ” made it a suitable basis for the construction of a dirt and shortdistance track-racing car, Set about the design and manufacture of parts to convert the standard product to one capable of putting up a high performance. The Chevrolet Bros. Mfg. Co. of Indianapolis (later known as the Arthur Chevrolet Aviation Motors Corpn.) produced first a special cylinder head for the standard ” ‘1’ ” Ford. Known as the Fronty Model R, this was a flat head with push-rod-operated overhead valves of 1i” dia., single induction port and carburetter, three exhaust ports, and a compression of 85 lb. in May, 1922, two Fronty Fords, using motors fitted with this Alodel II head, qualified for the Indianapolis 500 Mile Race and completed the whole distance at an average of over
80 ni.p.h. In short speedway events similar cars lapped the half-mile tracks at speeds over the 60 m.p.h. mark and the longer 11-mile tracks at 92 m.p.h. These cars, of course, embodied additional modifications to engine and chassis, which left little of the original Ford design unchanged.
The next head was the SR, a logical development of the 11, having two in-‘ duction ports and carburetters, two plugs per cylinder and increased compression of 100 lb. At Indianapolis in May, 1923, a “Fronty,” running under the name of the “Barber Warnock Special,” driven by L. L. Comm and using a unit with this SR head, qualified at 86.92 m.p.h. and finished fifth in the race, defeating, as the current account says, ” all foreign cars, such as Mercedes and Bugatti.” On the half-mile tracks that year the Sit distinguished itself by making fastest lap, driven by none other than the great Frank Lockhart himself.
For both the R and SR push-rod heads there was available an overhead camshaft conversion, with a single camshaft of 11″ dia., drilled for pressure oil feed to cams and bearings. The cams gave a lift of r arid the camshaft drive was by chain from the crankshaft, tension being maintained by an idler sprocket. The ultimate development of the ” Fronty ” head was the Type DO, built to special order under the personal supervision of Arthur Chevrolet. ‘I his was a 16-valve head, using double o.h.c., driven through an idler straight-cut gear wheel meshing with straight-cut gears on each camshaft ; the idler wheel carried a triple sprocket, which was driven by a triple roller chain from the crankshaft, the whole drive being enclosed and lubricated by surplus oil from the camshaft feeds and the chain tensioned by a similar method
to that used for the single-camshaft drive. The valves were inclined at 60v to the vertical, being 1-11/ in dia. with 1″ stems ; the cams operated directly on special valve collars, w hich were screwed to the valve stems and provided adjustment for clearance. Great attention Was paid to the design of the water passages in this head, as the compression was as high as 120 lb., and a special water pump was used to ensure a good flow, this pump being driven, in tandem with one or two magnetos, by a Special front gear set, which also carried the oil pump on its cover. Inlet and exhaust ports were of 11″ dia. there being four of each, and One, two or four carburetters were used. Owing to the drag always present with the planetary transmission of the old Model T” Ford, Chevrolet made a special crankcase and flywheel housing, which enabled “Fronty” owners to convert their older cars to use the ” A ” Type sliding gear transmission and clutch. ‘1 he
whole conversion could be made with hand tools only and be fitted regardless of the type of head or crank ; it was, of course, essential when dry sump lubrication was used for the longer events. In conjunction with the special ” Fronty ” heads were other essential parts of Chevrolet manufacture. For instance, several crankshafts were obtainable ; that used in units fitted with the 16-valve head was of disc web pattern, perfectly balanced, with 11′ main and r big-end journals an increase of *” over the standard dimensions. It was
drilled for the ” Fronty ” oiling system. A standard dimension, balanced and drilled crank was also supplied, this being
used in many cases with the It head. Special star-sectioned con.-rods, in chrome vanadium, were invariably fitted when the oversize crankshaft was used. Twin or single magneto sets, 3-gallon swnps, special camshaft gears, ball-bearing end caps and countless other aids to speed could be obtained ; in fact, most parts could be fitted either singly or in con
junction with others, enabling drivers to “soup up” their power units as fancy and finance dictated. ” Fronty ” chassis modifications were on sale to the driver who wished to build up his own track car. Flattened springs (and suitable brackets to mount these underslung), light double radius rods for both axles arid a special ball-bearing back axle asset’ bly with oversize half-shafts obtainable N%th five optional ratios (3, 3.25, 3.63, 4, 4.2 to 1) were supplied for use on long-distance speedway, I-mile dirt and I-mile dirt tracks as required. Special cam and lever steering gear, chrome vanadium steering arms and stub axle assemblies (on which ran 28″ x wellbase wheels with Rudge pattern hubs) gave a feeling of security as regards
directional control. -A narrow, deepblock, bull-nosed radiator was commonly used and bodywork made to suit the driver’s requirements.
The practical value of Chevrolet’s scheme to the American racing driver seems to be that he could start with a standard ” T ” Type Ford with, possibly, an ” R’ Type head, and, if he did well at the home-town dirt track, could step up his speed and the possibility of “getting in the big money” by purchasing ” Fronty ” extras whenever cash prizes allowed.
The ” Fronty ” was also sold as a complete car, ready for the track, fitted with a narrow all-steel single-seater body, not unlike the early E.R.A.s, the short tail carrying a double tank containing 10 gallons of fuel and 3 gallons of oil ; wheelbase was optional, but was usually 8′. The body was so narrow that when using the 2151) motor with the double camshaft head the whole of the inlet manifold and carburetter stood outside the bonnet ; no doubt readers may have noticed this in some of the early films which were made showing incidents on American tracks, such as “The Crowd Roars.” The price of the ” Fronty ” Ford in 1929 varied from $2,000 with the 215 engine, which had the It Type head and planetary transmission, to $2,700 with the 2151) motor, which had the 16-valve double camshaft head and sliding gear transmission. In all, there were live types of “Fronty ” Ford racing motors, and comparative peak speeds are interesting :—Type 215 with It head, single carburetter and planetary transmission, 3,600 r.p.m. ; Type 215A, which was the same unit, but with the single overhead camshaft and sliding gear transmission, 4,200 r.p.m. ; Type 2t5B, with the SR head, two Zenith carburetters and planetary transmission, 4,000 r.p.m. ; Type 215C, as the 21513, but with the o.h. camshaft and sliding gears, 4,800 r.p.m. ; Type 2151), 16-valve head, sliding gears and one 2 downdraught Winfield, 5,600 r.p.m. These speeds are for the standard motors as sold. Individual drivers no doubt obtained higher speeds by their own modifications; I heard only recently, from a mechanic who was with Millers in these days, that Frank Lockhart used a DO head cast in bronze on his 2151) motor for i-mile tracks, with considerable success. Many American drivers well known today ran ” Frontys ” in the 1920’s—Wilbur Shaw, ” Wild ” Bill Cummings, Howard Wilcox, ” Dutch ” Baumann, Louis Schneider and many others. In 1928 ” Dutch ” Baunnum, driving a “Fronty” (Type 215D motor), made 52 starts and won 43 firsts. I think this is a record for short track racing. He also lapped the Continued on page 64
i-mile track in 24.2 sees.! In most short track races in the 1920’s ” Frontys ” appeared in the first three, and in 50 and 100-mile races they often finished in first place ahead of Millers and Duesenbergs, cars costing in all probability several times as much.
One interesting photograph I have is that of Henry Ford himself, sitting at the wheel of the ” Fronty ” Ford which finished fifth at Indianapolis in 1928— he looks extremely uncomfortable ! I do not think that any of the Type 214 cars ever came to England, although the Conan Doyles had a 2-seater which was driven by them at Lewes [and with which A. E. Moss won a 1925 13.A.R.C. Handicap at 80.93 m.p.h.—Ed.] and by Dick Nash at Skegness. It was the subject of an article in MOTOR SPORT at the time and was not, I believe, the last word in ” Fronty ” design. Had Greenford progressed as ” Spike ” Rhiando hoped, we might have seen more of these most interesting ears.