Can somebody give me a ballpark figure on my compression ratio? Motor is a 408 Big Block (.030 402 from a 71 SS). Pistons are TRW L2328's. Heads are 292 Castings with large chambers and 2.08/1.72 valves, pocket ported and gasket matched. Head gasket is a Fel-Pro 8180. I have not assembled the short block yet, so I don't know how far in the hole the pistons are. Thanks.

I just posted this some where else. It's from "Auto Math Handbook" by John Lawlor

http://members.cox.net/jpeterson40/comp.jpg

I hate math!

I just noticed you were in WOON-socket. If you need a hand with anything, let me know. I'm a machinist so I have a decent amount of measuring tools and what I don't have I get generally get.

Jeff

Yeah, I'm right down the road from you. I go down to Competitive Automotive in Warwick once in a while to get parts for my car. If I need a hand with anything, I'll definitely look you up. Thanks.

Please go over to the ROSS Racing Piston site and use their compression ratio calculating program.

Our motors stock pistons are generally .025" down in the hole and you can input head combustion chamber cc that vary's from 50 to above 80 cc's as well as headgasket thickness that can vary from .015" to above .040", all for SB motors.. And regular four valve notch flat-top stock type pistons are generally about a -4 cc's. But if you are looking into either dished or domed pistons, then you will need to get that info from the manufacturer or possibly ask here and maybe somebody will know the info wanted..

pdq67

According to the Ross Piston's Calculator, with a 36.6 cc dome, 119 cc chamber, .039 compressed gasket thickness, .020 in-the-hole, I should have 9.75:1 Compression. Thanks pdq67 for the site info.