This is a short story on the development of an engine by the Ford Motor Company. This engine was the subject of many books, articles, and technical reports. I have seen this engine referred to as: the Dearborn Ford, the Ford DOHC, The Quad Cam Ford, the Cammer Ford, the fourteen gear Ford, and the Foyt Ford. The meat of this story has been plagiarized from several sources, but primarily from the Design and Development of the Indy Car by Rodger Huntington, The Racing Fords by Hans Tanner, and the S.A.E. report on the Ford DOHC Competition Engine by A.J Scussel along with the update second addition by Ak Miller.
The story begins shortly after the 1962 Indianapolis 500 race. The intent was made by the Ford Motor Company to launch a multi-million dollar Ford Indianapolis racing project to enhance their image in the mushrooming youth / performance market. Bill Gay, Executive Engineer of the Advanced Engine Department of Ford Engine and Foundry Division, assembled a team of engineers including Joe Macura and Richard Chen. Their objective was to build a racing engine of 255 CID, producing at least 325 hp, and weighing no more that 350 lbs.
The decision was made to start with the 260-CID production engine used in the Fairlane, Falcon, and Comet cars. The design project was divided into two phases. First, to baseline the 260 Fairlane engine that was to be the basis of the new engine. The second phase was to develop a reliable aluminum version of the engine. The stock 260 CID was dubbed the Stage 0 engine. The Stage 1 engine had revised intake and exhaust ports and 12.5:1 compression. The special intake manifold carried four 46mm downdraft Weber carburetors. The Stage 2 engine was an aluminum version of the pushrod engine reduced down to 255 CID. The block and heads were cast with stock patterns, but the cores were trimmed to change wall thickness, cylinder – head intake and exhaust port contours, block deck thickness, etc. Bosses were cast in the block to accept four additional cylinder-head studs per side. Forged crankshafts and pistons were used. Other major changes included shaft mounted rocker arms, gear camshaft drive, cast – magnesium oil pan, dry sump lubrication, electronic ignition, aluminum water pump, and vacuum-melt-steel valve springs.
The new engine was strong, and the engineers quickly exceeded 350 HP by experimenting with radical camshaft grinds, high compression ratios and the switch from dual throat 46mm Webers to 58mm Weber downdraft carburetors. Soon they were pulling 376HP at 7,200 rpm on 103 octane gasoline and getting 500 mile reliability. This new configuration came in at 344 lbs. complete with stub exhaust pipes.
Clark’s good showing in the 1963 500 race fired up the enthusiasm of the Ford company officials to develop an even better engine with the potential to dominate the Indy scene for several years to come. The new design objectives were to increase output by 50 HP over the 63 push rod engine, with a weight gain not to exceed 50 lbs.
At this point it was decided to lay out a new three-phase development plan for the new race program. Phase I would involve the design, fabrication, and evaluation of a double overhead camshaft engine that would utilize as many as possible of the basic components of the 1963 phase 2 pushrod engine. Testing of the Phase I engine confirmed that the cylinder block and reciprocating and rotating components carried over from the 1963 engine were more than adequate to withstand the higher demands in speeds and loads which would be made by the 1964 competition engine. These test showed that the new design would permit more than 400 horsepower to be achieved at approximately 8,000 rpm. Phase II would provide for a new series of experimental engines, incorporating design changes resulting from analysis of Phase I test results with special attention to combustion chamber configuration, induction system design, and to multiple ignition points in the combustion chamber. As a matter of interest, the dynamometer testing in Phase II was sufficiently conclusive to do away with the need for the testing of the Phase II engine in a vehicle. Phase III would be essentially the Indianapolis race engine, incorporating all design changes validated by the tests and evaluations resulting from Phase I and II. Testing during Phase III would result in the incorporation of design refinements of the final engines, right up to race day.
A few other components were carried over from the 63 engine. The cast-magnesium oil sump lubrication system with dual internal scavenge pumps were carried over with minor improvements. The ’63 pushrod engine had already been fitted with a gear drive for the camshaft, water pump, oil-pump and alternator in the magnesium front housing. For the new engine it was merely necessary to run an upper gear train off the center cam gear to drive the overhead cams. An aluminum tube was cast in place of the original cam for oil drain-back and block strengthening for 1965. The water pump, oil pumps and alternator, were retained.
For 8,000 + rpm operation, it was decided to beef up the connecting rods and pistons considerably. Very little weight was added, but the metal was more carefully distributed to reduce stress concentrations. Both rods and crankshafts were forged from chrome-moly steel, then hardened and shot-peened. Tri-metal bearings capable of sustaining 10,000 psi loads were used.
It was determined early in the program that the 58mm Weber downdraft carburetors used in ’63 would not be adequate for the increased air-flow demands of the four-cam engines. Ford technicians turned to the Hilborn fuel injection system. They literally re-engineered the metering system for more precise air/ fuel curves. Spring-loaded economizer valves and secondary by-pass jets shifted the curves to more closely match the engine’s fuel demand when accelerating off the corners, and on through the speed range to peak straightway RPM.
The following is what finally evolved; four valves in a pent-roof shaped combustion chamber, single plug at the center, with the intake port routed between the two camshafts. The exhaust port went inward and exited on the inside of the cylinder banks. This layout had two important advantages. Flow test showed the vertical intake port gave slightly better volumetric efficiency than a conventional horizontal port. It also had the benefit of accessibility of carburetion between the camshafts with the V-8 cylinder arrangement. Bringing the exhaust ports out in the center of the V also gave more flexibility for designing tuned exhaust-pipe systems. This had been a problem with the 63 pushrod engines. Ford engineers experimented with six to eight exotic pipe layouts, all giving significant power boost over conventional straight stacks.
The 1964 dual overhead cam engine, gave maximum output on 103 octane gasoline, developing 425 HP at 8,000 rpm and weighing in at 395 lbs., less flywheel and exhaust pipes. Five hundred mile reliability was confirmed by dynamometer cycling instead of tedious track testing. This method seemed to work as well above 8,000 rpm as it had at the lower speeds used in 1963. Several vital design changes were made in rods, bearings and valve train parts as a result of this testing. The design was frozen and declared race ready in April, 1964.
Some major improvements were made in 1965, by putting small booster ventures in the main throttle bodies, and discharging the fuel into the low pressure area at the venture throat. This broke up the fuel droplets into a fine mist, assisting vaporization and speeding combustion. They lost 5-10 HP due to the booster restriction in the air passages, but fuel consumption was reduced 10-13 percent. Oil flow was increased 50% by enlarging passages, and oil-feed pressure was increased from 65 to 90 psi. Oil filtration and cooling also got attention. Rod caps and bearing shells were strengthened to reduce distortion and bearing pressures more evenly. Ford engineers felt confident in extending the red line to 9,000 rpm after these changes.
Ford Motor Co. never actually sold and serviced the four cam V-8 engine. Once the engine was basically developed and firmly established as a winner in 1965, Ford contracted with Louis Meyer to distribute and service it. Ford manufactured parts at their Cleveland engine plant or jobbed them out, assembled the engines in Dearborn and shipped the engines and parts to Meyer in Indianapolis for distribution. The first year, 1966, they produced 20 complete engines to be retailed for $ 23,000. The Federal Reserve Bank of Minneapolis- Consumer Price Index Calculator equates $ 23,000.00 of 1966 to $ 152,950.00 at 2008 values.
Even with the hefty price tags that followed, there’s no question that the four cam engine project cost ford a bundle of money. They say nearly $10 million, or approximately 66.5 million in 2008 dollars. The project was then turned over to Ford engineer Dan Jones with the help of Don Hayward to continue refinements and adapt turbo charging in the late 60’s Then Henry Ford II suddenly decided to pull out of all forms of racing in 1970. It is said that Henry appeared at a senate comity hearing, and when asked how much he invested in the racing project as opposed to how much was spent on auto safety, he promptly pulled out of racing. At this time the four-cam engine business was given over entirely to A.J. Foyt, to handle from his large shop facility in Houston, Texas. Foyt with his engine man Howard Gilbert, had been especially innovative in developing his own stable of Ford engines in the late 60’s. The Ford brass felt he would be the ideal one to carry on the work. Ford gave him the patterns and tooling to make the parts, and more than $200,000. worth of spare parts from shelves in Dearborn and Indianapolis.
In order to meet the rules for running a turbo charger, the cubic inch displacement was reduced from 255 CI down to 160 CI. In order to accomplish this reduction changes were made to a shorter stroke crankshaft, and rods and pistons were redesigned. The heads block, and oil system remained basically the same as the 255 CI engine. Because the Ford engines had removable cylinder heads, as opposed to the one piece block of the Offys, the four- cam Ford V-8 engine never seemed to be as comfortable with turbo charging as the Offys. The Fords never could use more than 80 – 85 inches of manifold pressure without damage to the engine. Some of these problems might have been solved if Ford hadn’t pulled completely out of racing. A.J. Foyt took over the four-cam engine business, but he didn’t have the resources or facilities to do the extensive kind of development needed to sort things out. Foyt and Howard Gilbert experimented with several piston designs and ring combinations. They even tried to increase turbulence and speedup combustion by inserting sleeves in the intake ports to increase gas velocities entering the cylinders. With all their testing and experimenting, they were not able to use more that the 80-85 in. manifold pressure for any length of time. The engine would develop about 825 HP at 9,600 rpm at this boost.
Under these conditions it’s not surprising that Foyt wasn’t competitive in qualifying for the race in 1972 and 1973 when the top Offys were running 10-20- and 30inches higher manifold pressures. His qualifying speeds were down 7-10 mph and he couldn’t keep up in race traffic either. When he tried screwing up the boost without richening the fuel mixture, the engine would fail. If he ran rich enough to save his pistons, he lost time making extra pit stops. In the early 1970s the Offys had the advantage.
This situation was reversed in1974 when USAC went to an 80 inch manifold pressure limit for qualifying and put a cap of 280gallons of total fuel consumption for the race. The boost limit was an attempt to slow the cars down a little for safety reasons. The new rules gave the Ford engine a new lease on life. With twice the valve and port area per cubic inch of displacement of the Offy, the Ford developed about 50 HP more at a given manifold pressure. Foyt reported 825 HP at 9,600 rpm for his ford at 80 inches of boost. A typical Offy was good for 770 HP at 9,000 at 80 inches of pressure.
Foyt’s qualifying speeds were suddenly 2-3 mph faster than his opposition. He sat on the pole in 1974 and 1975 and was 2nd row in 1976 and 1977. He finished in 2nd and3rd places in 1975 and 1976. He won in 1977. As the saying goes all good things must come to an end, so it was with the Ford Dearborn DOHC V8 engine.
It was about this time that, Dan Jones, the man in charge of the Quad Cam Ford Turbo Development, along with George Bignotti, and Sonny Myers, had Fords design engineer, Donald Hayward, design a new engine. The new design was a much smaller, and lower profile, Quad Cam Flat Six engine of which two were produced. This new flat six engine showed great promise for Ford, but the British Ford Cosworth division, also a four cammer V8 was in a more advanced stage of development, so Ford allowed the Cosworth to claim the new glory. And so the teams moved on to the new Cosworth power, and the Dearborn Fords became obsolete. If Ford had put their backing behind the new Don Hayward designed engine, the new Ford Dearborn DOHC F-6 may have provided the winning combination for the next ten years or so.
In closing on the development of the Ford engine, I would like to include a point of interest that I was told during my visit with Howard Gilbert in 2005. Howard said that he had just finished building up a turbo charged Ford and had it installed on the dynamometer in Foyt’s shop, when in walks A.J. and says “ I wonder just how much horse power it will put out before it blows “. At that Howard let her rip and the indicator went to 1,440 HP as the engine came apart. A truly amazing engine developed and refined by truly amazing men.
DISCLAIMER: This web site is devoted to preserve and inform people about the first Ford Quad Cam engine. This site is not for profit, nor is its accuracy guaranteed.
I dedicate this site to two people, good friend and long time race car enthusiast Ed Monroe 9/10/07, and to Howard Gilbert 2/4/08, friend and the most respected Indy crew chief/ mechanic that I know of.