5 Mystery Muscle Motors of the 1960s that Detroit Never Sold in a Car

1969 Plymouth Weslake DOHC V8


It’s unknown whether this project was purely for racing, or Plymouth had the intent to offer the motor in a street car at some point. Keep in mind that the entire Chrysler group witnessed the excitement and positive impact on the brand when the previously race-only 426 Hemi was offered in production cars.

Following the 1968 season, Richard Petty announced he was leaving Chrysler and going to Ford for the 1969 NASCAR season. The money allocated for Petty was used to develop the Plymouth Indy DOHC V8. Design work began in February 1969 and running engines were provide to Andy Granatelli’s STP race team less than 90 days later.

The designer of the special cylinder heads was Harry Weslake, a British engineer best known for his expertise in gas flow through internal combustion engines. If you recognize the name, it may either be for his V12 engine in Dan Gurney’s 1967 Belgian GP winning Eagle, or the Gurney-Weslake cylinder heads used on GT40 Fords.

The engine lacked top-end horsepower necessary to compete at the high speed oval tracks, it had plenty of bottom-end torque which made it quite competitive on the short oval. In fact, Art Pollard drove the Plymouth-Westlake engine to victory at the 200-mile Indy car race at Dover, Delaware on August 24, 1969. This would turn out to be the only victory for Plymouth in the history of Indy Car racing.


Categories: Gear Grinding

Chris Riley
About Chris Riley

I have been wrecking cars for as long as I've been driving them but I keep coming back for more. Two wheels or four, I'm all in. gives me a chance to give something back to the automobile community.