LQ4 with stock flycut pistons...?

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Apr 4, 2010 | 09:48 PM

Jrmotorworks

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Staging Lane

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From: Shakopee, MN

LQ4 with stock flycut pistons...?

Long story short, purchased a used LQ4 from a yard, was from an 07 1500 Classic (old body style). Casting numbers show up as LQ4/LQ9, VIN pulled up the LQ4 which is what I expected.

So... I pulled the heads off to swap cam and put on my L92 heads and this is what I found when I pulled the heads off:

First of all, they are the dished pistons so I know it's an LQ4... But where did the flycut pistons come from? I couldn't see any evidence of the engine being opened up previously. Haven't gotten the cam out but I assume everything to be factory. Did I get an added bonus from the factory, or did someone have this done?

These don't appear to be aftermarket pistons. We're very confused over here.

Thanks for any help at all here.

My other question would be, since I have this new found space can I run a thinner head gasket on my L92's to get some more compression?

Thanks everyone,

Jeremy

Apr 5, 2010 | 01:10 AM

tspence45

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From: Monmouth, Illinois

As long as you don't go too big on the cam, you could even have the heads milled down a little to bump compression.

Apr 5, 2010 | 05:40 AM

69LT1Bird

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The factory never did that to the LQ4's so someone has been in there already.

You can get the L92's milled .030, stock gasket thickness (.052) and still get about 10.5:1, clay them up and check, you may be able to go thinner on the head gasket with the flycut.

Apr 5, 2010 | 06:25 AM

outkast6991

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From: lancaster,pa

umm why are the cuts opposite of each other? they should be on the same valve angle

Apr 5, 2010 | 07:00 AM

DMMizell

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Those are stock LQ4 pistons. The valve relief is for the exhaust.
There are 2 reliefs so the piston can be used on either bank.
This a picture of my 2006 LQ4 with additional Flycut for L92's.

Thanks,
Dave