just wondering how much PSI u can boost till they recomend o-ringing your block and heads? thanks

Josh

 

for a non intercooled app weiand says no more than an effective compression ratio of 12.5:1

on most 9:1 compression 350's this is about 6 PSI of boost.


But technically, you shouldnt need to O-ring so long as cylinder BMEP's are kept below 300 PSI (such as very high boost / N20 at a very low RPM) and as long as detonation is kept under control you can run as much boost as you want without an O-ring.

its the super high cylinder pressure, and detonation that blow headgaskets.

if you Oring your motor, then its basically proof against #1 the super high cylinder pressures, but NOT detonation. if your block is Oringed then instead of blowing a headgasket you will put a hole somwhere in your bottom end. not good.

 

head gaskets are a good safety seal, I will be using felpro loc-wire head gaskets as my "fuse"

 

thanks for the info guys. I WON'T be o-ringing my block then :-D don't wanan loose the bottom end, head gaskets are easy :-D

 

My block/heads aren't o-ringed and I haven't had any problems with 20+psi of boost. As was already said, just avoid detonation and the resulting spikes in cylinder rpessure and you should be fine.

 

I think this is what people are referring to-lean A/F & boost don't go together. Here is lean@ 18+ lbs. of boost

 

holy mangled gaskets batman. Are those JE/SRP pistons? did they fare well?

 

Yes, those are JE blower/turbo pistons. They held up all three times!!!!!!!!!

 

in that picture is your block cracked at the stud? what kinda gaskets were u using?

 

I am also using JE blower pistons, 9.5:1 in a 6" rod 383 motor. Its not built yet, but that picture gives me comforte.

 

The block isn't cracked-that is old gasket. I was using a standard FelPro race gasket. Now the heads are cut and WireLoc's installed.

 

they look just like mine thank *** they survive :-)