Subject: Re: 7500rpm 383 by Slalom4me on 2008/9/30 20:46:48
Quote:
sliding wrote: I plan to build a new engine soon. It will be 383 stroker but I want engine that will rev to 7500 rpm with ~7000 rpm peak power.
This engine/car is not my daily driver, but it's driven mostly on street with a few road races a year. Now, I'm not too concerned about street drivability, but I'd like this engine to last.
What are your opinions, suggestions.......
My vote is that an engine with a 3.75" stroke won't be a durable, reliable powerplant if it is roadraced to 7,500 periodically.
Piston speed at 7,500 RPM for this combination is 4,690 feet per minute. It is high to begin with and there is no margin for mishaps. Miss a shift or overrun on a downshift and see 7,800 RPM? - piston speed rises to nearly 4,900.
If you want durability and do not want to be frequently inspecting and maintaining the engine, then aim for a red line of 7,000 and have HP peak several hundred RPM below this.
Otherwise, if 7,500 remains your goal, then choose a shorter stroke to bring piston speeds down at this RPM.
