Lotus Elan and Lotus Elan Plus 2 Forums

Couple of questions regards optimum Compression ratio (on California gas)
Q1
What is the highest static compression ratios are people on the west coast of the US building there engines to that are intended to run on the 91 pump gas?
Q2 what was there dynamic CR measured after build?
Thanks

10.3 CR California pump gas 91

I concur with our Napa lad. I can do 10.5 with B cams. Dynamic compression numbers can vary depending on: displacement, cam profile, etc. My 1725 cc LB block, Stromberg head will provide 195 psi. This is in my Elite/Elan MK II with a C-4 automatic gearbox. Elan S2 frame, stretched 4.125 inches to accommodate the Elite wheel base, full adjustable suspension and re enforced, all on our 15 inch wire wheels. She did gain a bit of weight. Had to use the Stromberg head as the C-4 is vacuum controlled. Hope this is helpful. Cheers. Mike, only 45 minutes from Napa.

Please... I appreciate some additional feedback
Thanks

While I'm not in California, we have 91 octane locally, and my 1720cc twincam (fully ported, large valves, high lift/short duration cams) runs just a bit over 10.3 static with no issues/pinking etc on the 91 octane. It does run a custom curve in the distributor with total advance listed to something like 28 degrees IIRC.