I was looking at my build sheet for my 454 (.030 over - 460) and decided to look up the pistons that were put in my motor. They are TRW L2349. When I look them up the description say's they are for a 1970 LS6 Closed Chamber. Builder says my compression is around 9.4:1. Are these flat top pistons? Just wondering what I have in this motor.

Scott

Whats your combustion chamber volume head gasket thickness? Are there valve reliefs? if so what are there volumes?

It is running Fel-pro marine gaskets part # 17040 which has a thickness of .039. The heads are Rectangular port GM's that were worked by Scott Shafiroff Racing in Long Island. They have valve reliefs but I don't know the volume. I should have gotten more info from the builder, but it was the last engine he built before he retired to Florida. Engine was built using a 1989 454 Mag as a base (just block and crank).

You realy need to know the combustion chamber volume. If they have been pollished the volume could be up a bit. Afew cc's at a low compresion dosnt change anything much but at high comp ratios it does. The piston mfg should have comp ratios published for your pistons like 110cc, 116cc, 118cc heads etc.

Thanks for the information. I'll have to do a little more research on this. I really don't even know what's been done to my heads except they have been pretty worked over (wedges have been installed too). I want to call Shafiroff Racing and see if they would have any record. Ran the motor all last season and it runs great. Builder estimates around 470 + HP. Wish I had it Dynoed but by the time it was done he had already moved his Dyno out. Oh well....

Those pistons are for closed chamber heads. 29.4 cc .210 dome, pressed pin, 11.18 compression at 106.9 cc chamber. I dont know how they would work with open chamber heads which is what you likely have.

Hmm.. Thanks for the info. Just want to know what I got. I can't complain. Powers my little boat (24 ft overall) to around 70 which is about as fast as I'd want to go with my hull. Builder was supposedly one of the better in CT, so I trust him. Did a lot of the engines for Moroso.