I have obtained a set of LQ9 heads that I intend to have milled .030" ( I'm told that this will bring the compression back up to 10:1) that I will be using on a stock 2001 LS1 block. I would like to use a cam somewhere around 224/114, which is said to be average these days. My question is ..........with the milled heads, will I encounter valve to piston clearance problems? Any input would be greatly appreciated. Thanks!

 

depends on the lift of the cam..what would the specs be???

 

Come on..........help me out guys! Someone has to have tried this combo before. The cam will have a .558 to .560 lift. If I could get the compression up to around 10.5:1 or so, I'd be a very happy man! Thanks.

 

just completed h/c swap on 04 C5 A4 with a 216/224 .551 with 1.8 cranes so .590, pp ls6 style heads unmilled, had .095 on intakes. used the mr gasket 5713G and 5714G head gaskets, .042 compressed, pistons .007 out

 

Hey.... thanks man! Do you feel comfortable with .007 clearance? Not questioning your set up.........it's obviously working for you. Just wondering what is considered the minimum safe piston to valve clearance. Now all I have to do is figure out how close the milled heads will put the valves to the piston with that cam??? Thanks again for you input.

Oops.......I misunderstood what you meant by piston out .007. You are referring to the relationship between piston and deck height, and that the relationship between the intake valve and piston is .095, correct?

 

correct, p/intake valve was measured @.095. with pistons out .007, and a .042 head gasket, ended up with a .035 squish

 

gone as close as .060 on a carrillo rodded 418 dry sump small block, but would want minimum of .080 on LS1

 

So in your opinion, would milled LQ9 heads @ .030" for a compression ratio of 10:1 or so, with a 224/.560/114 work with out potential piston to valve clearance problems? Thanks for your help!

 

www.vincihighperformance.com check this site, Roger states all of their cams with .551 lift with 1.8 rockers will provide adequate p/v clearance. lift with these rockers is .590. duration, or lack thereof is key to maintaining adequate clearance. if you are running stock intakes, 2.00, you should be fine. i'm running 2.055, unmilled heads and have .095 p/v. still a good idea to degree cam and clay piston to check for p/v

 

here is my setup
LQ9's milled .030"
7.40" pushrods (considered stock length)
228/228 .575" lift 113 LSA
LS6 valves (a hair longer than stock)
6.0L MLS head gaskets
Stock 99 block and pistons

I have had no P to V issues with this setup and have been pleased with the gains. I will tell you what everyone told me to do when I was asking the same questions. 'Check it for yourself'. It's the only way you will know for sure. Good luck with your new setup.
-Josh

 

while you are checking smoothzee, measure how far ALL pistons come above deck at TDC, then buy 5713 G,5714G mr gasket head gaskets, if they all are out about.007-.008, these gaskets will give you about .035 quench

 

better to do it right, rather than do it over

 

Thanks for your response.........it is clear and straight to the point. Just what Iwas looking for! I will definitely check things out step by step during assembly, (darned good advice)!