LS6

I want to have 11.0 CR with L92 heads. Thus to what value needs the heads to be milled?

gtotoocool1

iTrader: (6)

depends on the size of your motor.need more info.

LS6

You are right

You deserve more details

The engine specification:
-Bore: 4.0845"
-Stroke: 3.622"
-Cylinder Block: LS1 re-sleeved
-Cam shaft: 227/239 114LSA
-Heads: L92 (Casting 823)
-Melling Oil Pump (295)
-LS7 Lifters
-Trickflow double timing chain
-LS3 instake manifold with LS3 fuel rail and injectors
-102mm throttel body

A_VAS

iTrader: (16)

head gasket thickness needed

delphigto

iTrader: (4)

What cc pistons?

Pwebbz28

iTrader: (31)

Stock is 10.7 so with the added displacement I wouldn't say much at all if any.

LS6

Greeting

The piston's are flat (original LS3), ooohhh sorry, I ment to say the larger size of the LS3 piston (4.0845") flat type
as far for the gasket, it will be original thickness (I think it is 0.052")

Thanks...

3pedals

iTrader: (3)

LS3 pistons(4.065") wont work with your 4.0845" bore. I would buy pistons with the correct dome/dish to get you where you want to be compression wise.

LS6

Sorry, I made a typo mistake

it is the LS3 piston of larger size (4.0845") and it comes flat.

There is a softwear that calculate for you the compression but it is a trail version which is expired.

Thanks

KCS

iTrader: (20)

68cc will put you just a tad over 11:1.

litle88

iTrader: (20)

http://www.wallaceracing.com/cr_test2.php

There are more here too....
http://www.wallaceracing.com/Calculators.htm

LS6

The links provided are great, however it does not provide me to how many mills will yeild an XX.X CR

3pedals

iTrader: (3)

I cut .050" and it reduced the cc's to ~60cc

NemeSS

iTrader: (127)

If u use ls9 gaskets.
The scr will be 10.86:1
Assuming out the bore is .010
Assuming pistons are flat without a dish or any relieves
To get 11:1 on this motor. Only need to mill about .005
Off the heads.
Based on the info you provided and values missing that I aasumed.
But its not certain, unless you have exact values for all 5V
V1 4.0845x3.622
V2 70cc
V3 4.0845x.010
V4 4.1x.051 (LS9 head gasket)
V5 0
= 10.86:1 SCR
To gain 11:1 from this motor. .005 must be removed from the cylinder head surface.

NemeSS

iTrader: (127)

Do you have a part number for those overbore LS3 pistons?

Remember if using an aggressive long duration, high lift cam.
PTV clearance must be verified before any machine work on heads.
This will determine if pistons will need valve relieves cut in pistons, then must find value of relieves.
This will change V5 if so. More than likely if using real flat top piston.
Then can proceed to find value of amount need to mill off cylinder heads.
It will be more than previous mentioned .005 if relieves are cut in pistons.

I wouldnt/dont have any machine work on heads unless I have my cam card in hand to find the dcr/scr im looking for. And then proceed to have any machine work on heads or pistons.
I prefer to use .015 out the bore for every build if.possible and use .050 compressed gasket if possible to achieve .035 quench

Wnts2Go10O

iTrader: (12)

you need a 65cc chamber

LS6

The cam is 227/239 --- 0.613/0.623 LSA 114 ICL 114
With the above cam & milling the head to 0.030", will the CR be around 11.1? Will the pistons require notching with heads milled to 0.030" with the above mensioned cam?

bww3588

iTrader: (49)

does anyone know how much milling it takes to remove 1cc from an LS3 head?

Patrick G

iTrader: (14)

About .006" (six thousandths).

bww3588

iTrader: (49)

so its less than an LS1 head? I have heard its .007 for an LS1 head.