.020 or .030 mill with 862 heads?
.020 or .030 mill with 862 heads? Hey guys, just looking for advice on how far to mill the 862’s for my SBE LS6 with a TSP 228 cam. Will be using stock .051 gaskets but looking for as much compression as I can get with safe PTV clearance. Will be putting 2.00” valves in as well. Engine is on holley terminator X and E85, 05 CTS V, street car with mild manners. I haven’t seen too much info about 862’s on LS1/6’s while searching
Derek
Derek
What he's getting at is that if you knew the current P-V then you'd have a good idea of just how much you can mill or how thin of a head gasket you can get away with for compression.
TECH Apprentice
Joined: Aug 2009
Posts: 302
Likes: 123
From: Louisiana
I would CC the chambers to see where you are at now. I have seen them as large as 65cc. Use an online Compression ratio calculator to plan out what your CR will be. I wouldn't cut them more than .030.
I was kinda hoping for a round about estimate from someone. Still have stock 243’s on it. Not much info out there for 862’s on an ls1. Reason I’m doing it is just because I have the heads laying around, I trying my hand at porting and the car doesn’t have to be down for more than a few hours
