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Lq4-Looking to boost up the compression

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Old 09-09-2010, 06:30 PM
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Default Lq4-Looking to boost up the compression

Time for something new, I ditched the LT1 and looking to run a LSX with a Carb

Car weight- est 4500lbs give or take
Hp/trq Goals- 420 RWHP would like to shoot for 450 /NA no power adder
Tranny- Built 700r4
Rear End- I have a 8.5 10 bolt already built
Possibly 150 shot after the Hp/trq goals- not 100% sure on this part though
Car is not a daily driver- Will see little to no track time, mainly a street car on weekends. Also not concerned with smoging
Pump gas
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Motor will be a lq4(just because I can get one real cheap). I already have a basic parts list for common upgrades like arp rod bolts/ported oil pump/long tube headers etc. etc. I can go on.

My main concern and area I'm seeking help in is upping the compression of the motor. Thinking 10.5.1? or so.

I want to run with a set of L92 heads (btw any sponsors on here doing good port work? Someone that can also offer me a custom specd cam as well)

Plan is to tear down the motor and do a little cleaning with new bearings etc, So since everything is apart I want to swap in some new pistons to help boost up the compression as well with the l92 heads, Any suggestions? (part numbers please) On about a $700-750 budget a decent set that will handle the 150 shot if I decide to toss it at the motor.

Basically wondering what combination with some milled L92's/Head gaskets/pistons can get me to my compression goals. Looking for suggested parts numbers so I can buy everything needed for the short block so when I get the motor home I can slap on my heads/carb intake and carb.

Last edited by BOXCHEV; 09-10-2010 at 12:09 PM.
Old 09-09-2010, 06:47 PM
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SDPC is selling new ls3 heads for $375 each.contact Patrick-G for a great cam.TSP sells l92 set the way you want.
Old 09-10-2010, 11:55 AM
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Ttt...
Old 09-10-2010, 05:38 PM
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milled 243s will bring the compression up.
Old 09-10-2010, 06:33 PM
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Just mill .030 off the heads and you are at 10.5

Most common LQ4 specs

Pistons = 6.7cc dish
pistons = .007 - .010 above deck
GM 6.2L head gaskets = .051 compressed
head gasket bore = 4.065



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