sroach20

iTrader: (31)

i have a stock lq4 with a 224/230 .581/.592 114 cam. i just got a pair of l92 heads and want to make sure i can mill .030-.035. i will still check ptv, just want to know on the milling.

69LT1Bird

iTrader: (1)

I took .030 off with no issues

Rock_Daddy

iTrader: (8)

How much of a comp. increase did you get or expect to get with the .030?

69LT1Bird

iTrader: (1)

I cc'd the heads before and after, I now have 62cc chambers and I used cometic .045 gaskets and I have 10.89:1 cr. My piston are out of the bore .010.

Rock_Daddy

iTrader: (8)

Plenty of room still or is it close with your cam? (P2V)

hymey

I thought it would be higher than 10.89:1. I am at 10.9:1 with only 20thou off.

sroach20

iTrader: (31)

how are all of you getting these numbers? if .006 takes off 1cc and i mill .030, that is 65-66cc's. with a stock lq4 i come up with around 9.7:1 or 9.8:1.

69LT1Bird

iTrader: (1)

Stock L92 combustion chambers are 68.4cc +-1.0

.030 off would make them 62cc roughly.

There are other things like like the piston over the deck, headgasket diameter, head gasket thickness etc. that go into the equation. Not every one is the same. I cc'd my heads and they came out to 62cc's, .045 cometic headgasket, piston up .010, stock lq4 pistone have a 6.7cc dish also.

sroach20

iTrader: (31)

okay, i kept reading where everyone says the l92s are 71cc when they are actually 68.4.

BlownVette 2001

iTrader: (2)

Suppose to 70 CC's according to factory specs. Give or take 1 or 2 CC's either way.

Rock_Daddy

iTrader: (8)

W2W measured mine and I don't remember exactly but it was 69 something.

69LT1Bird

iTrader: (1)

I have looked at the blueprints to get the specs so take that for what its worth.

sroach20

iTrader: (31)

sounds good. off topic, how many on here used the ls3 intake and what did you do for the map sensor?

hookemdevils22

iTrader: (12)

Agreed. There's a lot more going on than just head cc's. And the factory heads will differ by a little bit - it's best to measure before and after doing any milling.

Good idea: check p2v clearance with a used head gasket (if you're using the same gasket type - to simulate compressed state) using putty or something. Slowly turn the engine over to make sure. I believe that .600 lift will work with stock L92 heads (I BELIEVE!!! DON'T TAKE MY WORD AND F%*$ UP YOUR MOTOR!!!).

-TW

sroach20

iTrader: (31)

ive done ptv and all of that stuff several times. i was only asking because ive never dealt with the l92 heads.

hookemdevils22

iTrader: (12)

ya, they do have that whole "giant intake valve" thing going on, which definately makes them unique. i wasn't insinuating that you didn't know what you were doing, just adding my thoughts.

68 RS Convertible

iTrader: (1)

I just finished my first 6.0 build with L92's. Flat top Mahle pistons which have valve reliefs cut into the pistons. I had .025 milled off the L92's. Running GM .051 thick MLS head gaskets. TSP cam, I'm at work so I don't have the exact spec's for the cam, I think its .598 intake/ .603 exhaust lift. No PTV issues.

sroach20

iTrader: (31)

what did everyone do for the throttle cable bracket?

69LT1Bird

iTrader: (1)

I have a Holley 90mm and they come with a bracket.

BlownVette 2001

iTrader: (2)

I'm in a 2001 vette so I had to get new wire harness. Using a 90mm TB on LS3 manifold.