The Editor Discusses This "Hot-Rod" Business
The "hot-rod" craze, which originated in Southern California in the late nineteen-thirties, has spread throughout America. Over here we find the speeds achieved by "souped-up" L-head engined American cars over a flat-out quarter-mile difficult to believe, in spite of electric timing. After all, a 1932 Ford V8 coupé, sans wings, doing 120 m.p.h., takes some swallowing, and perhaps that is as much as we need say on the speed aspect of the "hot-rod." The fact remains that your American speed-worshipper — the Sports Car Club of America will have nothing of such worship, preferring to encourage the true sports car, vintage vehicles included — can buy all manner of proprietary parts with which to increase the performance of his Ford or Chevrolet. What is even more interesting is the manner in which data on what to do in order to achieve given results is freely available, in contrast to the rather secretive attitude on "hotting-up" production cars which prevails in this country.
For instance, two of "California Bill's Hot-Rod Manuals" have reached us and shed much light on the "hot-rod" cult. ("Hot-Rod Manual" and "Chevrolet Speed Manual," both by Fred W. Fisher, Los Angeles; two dollars each.)
Suppose, for instance, that you have only a model-A or B four-barrel (four-cylinder) Ford at your disposal. There is no need to be depressed, no need at all. You will be told that in California cars so engined have exceeded 120 m.p.h. and that one, a "belly-tank streamliner," has done 141.06 m.p.h. Note that ".06"; obviously the timing has all the appearance of being scientifically conducted. Opening your eyes and your purse you will buy a four-port head and four carburetters from Mr. George Riley, being careful to install them on a model-B block and crank assembly, as being more rugged than a model-A. This will cost you approximately £85, or you can search for a secondhand Ford Port, Cragar, McDowell, Alexander, Frontenac or other set-up, or wait for Rudy Moller to get his eight-port heads on the market again. If all else fails, you could forgo o.h..v. and put on a Roy Richter Super Winfield flathead, of either 7.5 or 8.0-to-1 compression ratio. Carburation can be looked after by Burns, Thomas, Riley or Winfield instruments, but probably your best bet is to use one or more V8 carburetters on a special manifold. Now get out your purse again, because with all this increase of power you will need to have your bottom-end re-babbited and pipes inserted to pressurise the mains and big-ends, and this is a specialised job, for an expert such as Jack Taylor. Stock rods will do, but with solid babbit for the pressure oiling, again a job for the expert, and the counterweighted model-C crankshaft should be drilled by this expert so that you can get oil to your re-babbited bearings. Don't put your purse away until you have bought a 3-gallon oil pan, a full-flow filter and a Wilbur Houghton oil pump.
With .003 in. to .0035 in. big-end clearance, .002 in. mains clearance, and .005 in. end-play at the rear main some users get 100,000 miles from a babbit job done by Taylor. Next you replace your camshaft bearings with, bronze ones having .003 in. clearance, and substitute metal timing gears, plugging the oil feed, as plenty of oil will reach them from the front cam bushing. The intake ports in the model-A or B block should be enlarged to 1 5/8 in., the exhaust ports by 1/16 in., and exhaust valves substituted for the inlet valves after enlarging the ports to 1 3/4 in. or 1 5/16 in. The ordinary water pump suffices but a belt-driven pump from a Hudson or similar engine may be preferred, and, naturally, racing pistons, with two 2 1/16 in. compression and one 5/32 in. oil ring will be fitted. Lincoln Zephyr valve springs should be used, either with standard or special cotters and collars, or 1935 V12 Cadillac 5-coil inner and outer springs with o.h.v. conversion heads. Forty-two pounds in weight can be saved if an alloy flywheel is purchased, and you may wish to install Ansen adjustable tappets. "Doc" Eyre will rebuild your ignition set, and if you want to go really fast, use a Ford Six coil with a Ford 81A replacement condenser or Zephyr condenser. You will already have bored out to 4 in. of course.
Suspension will be improved by torque rods running back from the front axle and the use of piston-type hydraulic shock-absorbers, after the chassis has been lowered by using a reset spring, a dropped front axle and a reworked frame kick-up. You will doubtless have converted to hydraulic brakes, possibly to column-shift gear-change, for which you follow "California Bill's" diagrams, and then all you have to do is to "channell " the body — i.e., lower it by dropping it over the side-members, and cutting down the model-B radiator grille and "chopping" the windshield.
Then, maybe, like Randy Shinn's Class D roadster, yours will knock out 130.76 m.p.h., stripped — maybe. If you are not so ambitious a model-A bottom-end can be pressurised, using a model-B crankshaft, if roadwork only is contemplated, and it is even possible to make do with splash, still using the model-B crank and rods.
Here I feel I should explain that "Hot-rodding" isn't only a matter of timed speed trials. In the States they recognise, amongst "souped" Fords, the Conservative road car, the Hot-Rod road car, the Super Hot road car and the Super Hot-Rod. "Souping up," in fact, in the Heinz tradition! The first-named contents itself with dual carburetters, compression ratio put up to 8.5-to-1, and a "semi-race" or "road" grind camshaft. Stock clearances are retained. The Hot road car will use a "hotter" camshaft, Zephyr valve springs, ported and relieved block, racing ignition, light flywheel, lengthened stroke, .0055 in. or .004 in. clearance solid-skirt pistons, stock main and big-end clearances, alloy cam-gear and a Mercury oil pump.
A compression ratio of over 9-to-1, "full race" camshaft, adjustable tappets, Zephyr or Buick valve springs, stroke increased up to 3/8 in., big clearances and dynamically-balanced crankshaft characterise the Super Hot road car. The Super Hot-Rod will have a rebuilt gearbox with Zephyr gears giving a 3.54 or 3.27-to-1 top gear, 7.00 by 16 tyres, a "super race" camshaft, very high compression ratio and piston clearances of .007 in. for sprint and. .008 in. for track work. They will also need exhaust baffles, which is puzzling until you discover that this merely implies blanking off the manifolding in the block to enable separate exhaust off-takes to be used.
The outstanding fact is that all these different special camshafts, heads, carburetters, pistons, ignition-sets and so on are available "over the counter" for those who crave "soup" with their Fords. Take camshafts. They come as Full-race, Semi-race, 3/4-full, Super, Super Jump and Track, from grinders such as Spalding, Harman & Collins, Smith & Jones, Winfield, Iskenderian and others. Each bears a label giving valve timing and recommended clearances.
When it comes to what to do to Ford V8, Mercury and Lincoln Zephyr engines there is no end to it. We find all manner of special components available, even to special dash panels. Many Zephyr owners are installing Mercury engines, which give about the same performance with lower fuel and oil consumption. Only the "motor mounts" require alteration. It is thought unwise to bore a V8 to greater than Mercury bore 3 3/16 in. — chamfering the piston top about 1/6 in. if early blocks are used. Mercury gaskets can be used with 24-stud heads. Mercury blocks bore to 3 5/16 in. and 59A and later blocks to 3 3/8 in., while 59Z truck blocks will go to 3 7/16 in. after taking out the sleeves. Ford pistons are rather heavy but late-type four-ring are better than three-ring. The Zephyr can be bored .075 in. oversize, and .055 in. milled from the heads. Zephyr, or the stronger Buick valve springs are superior to Ford, but Buick springs call for machined valve guides and Knudsen spring collars.
Block "relieving" and engine balancing are undertaken to practically standardised arrangements. Navarro, Weiand, Offenhauser, Edelbrock, Meyer, Sharp and others specialise in dual manifolds, with and without heating, and Spalding in two-point, two-condenser, twin-coil ignition, for the Ford range of engines. 1949 Ford blocks can be square-ported to 1/16 in. or 1/8 in. (width and length). Pressurised fuel systems supplement the mechanical pump on many "hot-rods." 5/16 in. dia. fuel lines, or at least 1/2 in. dia. for methanol, are used. Pounden-Gerde and Wico magnetos are largely employed, but special coil-sets are more popular, whether for bent-eight, four-barrel or six-holers. To put the later V8 engine into a model-A or B frame a 1934 cross-member is welded in, or a 1932 member, but the latter is weaker and entails removing the engine to remove the transmission. The model-A or V8 universal joint can be used, with Pt. 484520 A outer cap and B 4518 inner cap. Transmission should be V8, with model-A or B rear end, or V8 rear end in 1932 frame. A 1932 or later V8 radiator is essential, in a 1932 model-B shell. It is easier to use a 1932 V8 chassis, as no alterations are necessary. Steering should be model-A.
The stroke of a V8 or Mercury can be increased by grinding or milling the Mercury crankshaft journals off-centre to reduce the diameter by 1/8 in. New pistons are obviously required and Ford rods (21A-6200) and bearings (81A-6211) must be fitted. Engine speed will drop by 500 r.p.m. for each in. of added stroke. Unless a 1939 or later block is used, excessive machining of the crankshaft will be entailed. A 1/4 in. extra stroke is obtainable by using a 1949 Mercury crank in any 1939-1949 block without any mods., using stock Ford mains and 29A Mercury rods. 1949 Mercury pistons or special pistons must be fitted. If the 1949 Mercury crank is "stroked" 1/8 in. and 21A Ford rods are fitted, the stroke is lengthened 3/8 in. With a 1949 Mercury shaft be sure to use the 1949 Woodruffe key; earlier shafts have larger keys. "Stroking" does not weaken the shaft, but it should be dynamically balanced. This method of obtaining greater swept volume and higher compression ratio is, of course, employed on Mercury engines by Allard in this country. In the States up to 1/4 in. extra stroke is used occasionally.
Ford or Mercury blocks are relieved from valve pocket to bore by tapering to a depth of 1/8 in. to 5/32 in. and 1 5/8 in. or 1 3/4 in. dia. inlet valves fitted. On any 1946 or later block the heat riser passages may be ground out to 1 1/16 in. or 1 1/8 in. Gear ratios are rendered suitable for hot-rodding by using 1941 Zephyr gears, or if higher ratios are needed, 1946 Zephyr gears in 1939 or later Ford boxes, or Ford boxes back to 1937 if a 1939 lid is used.
Only the cluster gear, front main shaft and second gear need substituting. The 1941 Zephyr gives 2.33-to-1 low, 1.57-to-1. second, the 1946 2.12-to-1 and 1.44-to-1, compared to 2.82-to-1 and 1.62-to-1 for 1935-1940 V8 and Zephyr, and 3.12-to-1 and 1.77-to-1 for 1941 and later V8s. Ford axle ratios are 3.27, 3.54 and 4.11-to-1. Some special heads fit 21-stud blocks, including Evans and Meyers, and Cyclone heads alone permit the use of the 1937 in-block water pumps. Some of these heads give a rated compression ratio as high as 11.1-to-1. Moller Adams lists a wonderful inclined-o.h.v. head for use with all 24-stud Ford and Mercury blocks that is claimed to give 1 h.p. per cubic inch displacement on a compression ratio of 7.5-to-1.
From the foregoing it is clear that America takes "hotting-up" more seriously, so far as Bill Blog the baker and his mate the candlestick-maker are concerned, than we do in England. American readers will do well to study California Bill's publications, which tell you as much what to do to Chevrolets and Ford Sixes as to the other Ford models. I wonder, however, if it is worth all the trouble, or whether you wouldn't do better to order yourself one of Mr. Lyons' excellent "XK120" Super Sports Jaguars.
However, let us just see what they claim for all this "souping." A stock 1940 Mercury gave 90 b.h.p. at 3,500 r.p.m. With Navarro 9.25-to-1 heads power rose to 101 b.h.p. at 3,500 r.p.m., but decreased below 2,100 r.p.m. With these heads and a dual-carburetter manifold, generator now removed, 108 b.h.p. at 3,500 r.p.m. was realised. The torque peak moved from 1,900 r.p.m. to 2,350 r.p.m. Chevrolet and Ford Six engines are made to do 6,000 r.p.m., equal to piston speeds of 3,750 and 4,400 ft. per min., respectively. Fantastic speeds are claimed at the Lakes speed trials, for which safety-belt, ignition kill-switch and fuel cut-off are insisted upon. Roadster racing takes place in Southern California between cars without flywheels and having quick-change gearboxes, locked axles, high-geared steering and roll-over hoops. The roll-over hoops apart, it all comes back to what we have learned in Europe. Apart from supercharging and special fuels, nothing points to the power outputs necessary to achieve the speeds claimed in all-out sprints — is the answer in streamlining?
Superchargers are not generally available in the States suitable for Ford V8 engines and the McCulloch needs very careful rebuilding to get even 4 lb./sq. in. boost. Apparently the Spalding Brothers used a converted Mercédès-Benz supercharger on a 221 cub. in. V8 with Riley o.h.v. heads. With 12 lb. boost 132 m.p.h. was reached and a s.s. 1/4-mile in 12.5 sec. claimed. Barney Navarro is said to have got 237 b.h.p. at 5,350 r.p.m. from a 239 cu. in. V8 with converted G.M.C. supercharger, 8.75-to-1 heads and Hastings 14-225 sparking plugs. This gave a speed of 139 m.p.h. Even using methanol the engine still overheated and in its final form had size 63 jets in its four carburetters, passing "Solvex 105" fuel. Don Blair is reported to use the Spaldings' Mercédès blower on a Mercury engine and to get 141.06 m.p.h. in an unstreamlined roadster.
These speeds from very highly-tuned, extensively modified supercharged engines are rather more compatible than the 150-190 m.p.h. runs we are expected to attribute to unblown, stock-style L-head engines. I have analysed the "hot-rod" position in some detail, so that if ever a normal-looking model-A Ford coupé beats your British sports car from the traffic-lights you will know the reasons why. We will let California Bill have the last word. He tells us that a very light V8 roadster with a "full race" camshaft grind can, pull a 3.27-to-1 top gear and will peak at 6,800 r.p.m. in first gear, 6,200 in second and reach 4,800 to 5,200 r.p.m. in top "depending on the rest of the set-up." However, it "idles rough!"