I was reminded that dynamic compression ratio is the thing for figuring out how much compression is OK when factoring in your cam. Popular wisdom suggests 8.5:1 DCR is the max on pump gas (apparently) but other folks disagree. If you run an LQ9 (flat tops, factory 10:1) with 243 LS6 heads, you end up with something in the 10.94:1 range for static CR. Which makes people nervous. Yet they forget an LS2 had a 10.9:1 static CR from the factory, on the factory cam (LS2: 204/211 .525 .525). So clearly you should be able to get into the 11s without a problem if you run a hotter cam.
LS6 cam, for reference:
Code: Select all
204/218 int/exh @ 0.05" duration
0.551" / 0.547" int/exh lift
117 LSA