Question about LS3 heads on a 6.0L block
Question about LS3 heads on a 6.0L block Please excuse my ignorance if this has been addressed before....I've used the search function but can't find an answer....
When running the LS3 heads on an LS2 short block, is it worth it/possible to mill the heads to reduce the chamber volume to match the compression ratio on the factory LS2 motor? To the best of my knowledge, the stock LS3 heads have a chamber volume of 68 cc which results in a 10.7:1 compression ratio on the LS3 engine while the 243/799 heads that come on the factory LS2 have a chamber volume of 64 cc resulting in a 10.9:1 compression ratio.
I guess what it boils down to is, is it worth worrying about the difference in chamber volume and an associated loss of compression ratio, or do you just bolt the LS3 heads to the LS2 short block and the gains from the increased flow outweigh any minimal loss of power due to a decrease in compression ratio??
Thanks for the help guys....still learning as I go
When running the LS3 heads on an LS2 short block, is it worth it/possible to mill the heads to reduce the chamber volume to match the compression ratio on the factory LS2 motor? To the best of my knowledge, the stock LS3 heads have a chamber volume of 68 cc which results in a 10.7:1 compression ratio on the LS3 engine while the 243/799 heads that come on the factory LS2 have a chamber volume of 64 cc resulting in a 10.9:1 compression ratio.
I guess what it boils down to is, is it worth worrying about the difference in chamber volume and an associated loss of compression ratio, or do you just bolt the LS3 heads to the LS2 short block and the gains from the increased flow outweigh any minimal loss of power due to a decrease in compression ratio??
Thanks for the help guys....still learning as I go
yea I guess thats what Im getting at.....I know there are a number of people running a similar combo....are most just running the decrease compression, or actually milling the heads to maintain the slightly higher compression of the factory LS2 set up?
TECH Regular
Joined: May 2011
Posts: 433
Likes: 1
I would mill the heads and flycut the pistons, compression is your friend.
I recently flycut our LS3 pistons .100" and had 0.075" machined off of the heads, the difference in idle quality and throttle response is night and day!
I recently flycut our LS3 pistons .100" and had 0.075" machined off of the heads, the difference in idle quality and throttle response is night and day!
TECH Addict
Joined: Jul 2013
Posts: 2,189
Likes: 123
From: Portland, Oregon
Dyno Junkie, I did not even know it was possible/safe to deck LS3 heads down that far! That's like 3mm of metal being removed. What is that, a 57cc combustion chamber now, or thereabouts? Neat. Although I would not want to shave that much off the clamping surface of the heads for any sort of boosted or bottled build.
