tuj wrote:I guess I'm wondering what you call a 'production' engine? Production architecture? If so, then most of the SCCA national championships have been won with highly blueprinted and optimized 'production' engines. Spec Miata is a series where generally speaking, true production engines are used, nearly as they come from the factory.
What i mean with a production engine is the engine that is taken from a car allowed to drive on public streets and is not modified for racing (or very limited modified for racing).
So for example engines from one of these cars:
http://autoweek.com/article/car-news/500-hp-club
I Always figured that the engines one can drive on the public roads are not suitable for racing, but as i said in my initial post i am now aware of at least 2 unmodified engines that have been used in racing.
I guess i'm wondering if i pick an engine from one of the cars as listed above and put it in a formula-chassis and only allow some minor modifications for reliability, would it last for 2+ hours/500 miles racing?