I'm looking for a website that has TECHNICAL info on engines from WWII. I found a nice place to start: All Engines Data This site has types of engines and their horsepower ratings and RPM. However, I'm also looking for info on this like compression ratio, displacement, boost gain, critical altitude, and other information. If anyone has any websites they know of.....PLEASE leave a post so I can visit the site.
For engines used by civilian operators, go the the FAA website and search "type certificate data sheet," or TCDS. You will find a wealth of information there.