OFFENHAUSER: The Engine That Became a Racing Legend

36 vintage Indy cars are lined up on the front straightaway for the 21st annual Harry Miller Club Vintage Indy Car Meet. 50 cars were on hand for the signature event on the vintage oval racing calendar. [Photo by Russ Lake]

36 vintage Indy cars are lined up on the front straightaway for the 21st annual Harry Miller Club Vintage Indy Car Meet. [Photo by Russ Lake]

Turk’s Tracks
A Few Loose Lugnuts from Pit Row

By Gene Turk

When I think of famous engines that were designed and built in the last hundred years, names like Rolls-Royce, Merlin, Allison, Pratt and Whitney Cosworth, and the small block Chevy V-8 all come to mind. But one engine stands at the top of the list, the four-cylinder Offenhauser. The engine simply known as, “The Offy”. This little engine dominated American open wheel racing for more than 50 years and is still popular with vintage midget and sprint car racers today.

Ironically, this engine did not start out as a race car engine or was it called an Offenhauser. About 100 years ago, Harry Miller built his first four cylinder, double overhead cam, four valve engine of 220 cubic inches(3.6 liter) for marine use. This engine was very powerful and was used by many boat builders to set new speed records. Then in 1930, some car builder installed one of Miller’s 151 cubic inch marine engines in his automobile and set a new international speed record of 144.895 MPH. Quite amazing for 1930. However, the country was in the midst of The Great Depression and Miller and Company went bankrupt in 1933. But like they say, fate stepped in.

In steps Fred Offenhauser, Harry Miller’s chief mechanic and bought the rights to the engine, tooling and drawings. He then opened up a shop only one block from Miller’s company. Fred made changes and refinements to the engine that would lead to the engine becoming the indomitable Offy. Just about the time the engine was proving it’s way by winning races, another big change took place – World War II started and all racing activities came to a screeching halt as the country put all its efforts into war production. But the story does not end there. Actually, the biggest changes in the history of the Offy where just around the corner.

In 1946, Lois Meyer and Dale Drake bought the engine and design. It was under these two individuals that the Offy became the engine that dominated the Indy 500 and midgets for years to come. To be accurate, the engines at this period could be called Drake Offys. From 1934 through the 1970’s, the Offenhauser engines won the Indy 500 27 times. From 1950 to 1960, Offy powered cars won the Indy 500 pole 10 of 11 years. But it even gets better. In 1969 Lime Rock Park held its Formula Libre race. Roger Ward shocked the expensive and exotic sports car by winning the race in an Offy powered midget on a road race course. The story of this legend just keeps getting better.

A big change for the Indy 500 came in the mid-1970’s with the advent of turbo charging. This engine really came alive with 44.3 PSI of boast. They could now put out 1000 HP. The final Offy was 2.61 liter (159 cu in) and was restricted to 770 horsepower at 24.6 PSI of boast at 6600 RPM. This year’s winning Indy 500 Chevy 2.2 liter V-6 engine puts out about 710 HP at a very lofty 11,000 RPM. The Offy’s final victory came in 1978 in a car driven by Gordon Johncock.
Besides its high output per cubic inch-as high as 3 HP per cubic inch – the Offy was very reliable. It was of a monobloc construction. This is when the cylinder head forms both the cylinder and head in one unit. This eliminated the problem of blown head gaskets and cylinder head stud failure. This also allowed for lofty compression ratios of 15 to 1. The design also allowed for many different sizes of engines as rules were changed. Bores and strokes could be changed to give many ranges of engines. However, the following is a list of the most popular sizes:

1. 97 cu in. (1.5L)
2. 220 ” ” (3.6L)
3.270 ” ” (4.4L)
4. 255 ” ” (4.18L)
5. 252 ” ” (4.13L)
6. 168 ” ” (2.75L) Turbo engines to 1968 for Indy
7. 159 ” ” (2.61L) Turbo engines to 1969 and later.

So there you have it, just some of the great race history of an engine that started out in the fertile mind of one man who just wanted to power boats almost 100 years ago.

Share Button