This engine was built by Smokey Yunick and Ralph Johnson in 1973 for the Indy 500. It is a 207-cubic inch twin turbocharged Chevy V8. The engine qualified 26th and finished 28th with turbo problems. Fuel mixture trouble kept the engine out of the 1974 race.
In 1975, with Jerry Karl driving, it made the race, finishing 13th. Two reasons the car was not more competitive on race day were directly attributable to Yunick. He meant to back off the boost three inches but went eight inches instead. He also raised the water pump speed but forgot that the tach ran off the same gear. Karl just about had a heart attack when he saw the engine running at 9000rpm (the red line was 7000)!
This was the first engine to run Indy with synthetic oil. Yunick had no formal education but was considered one of the top minds in automobile engine design. He helped develop Chevrolets original small-block engine in 1955. The basic blueprints of that design are still used in racing to this day.