LS1 Stock Piston Question

[ZGOBYBY]

So I have both heads of my LS1 in my GTO, and I began cleaning the carbon off the pistons. While cleaning, I noticed some fingernail-width reliefs on number 2 and 4 pistons, exhaust valve side. I don't think that LS1 stock pistons had any valve reliefs, they were completely flat-top.

The knicks in the pistons are small... will this cause any problems for me? I think the pushrods I was running for the brief time during the summer were too long.

Any ideas? Thanks.

[BLK95-Z]

Did you buy it used? Sounds like its had some p2v contact in the past. As far as i know stock LS1 has flat tops

[ZGOBYBY]

I bought the car used back in '09, and did a cam swap in August. I'm thinking my pushrods are a bit too long and with mileage of the timing chain, I think it caused some PTV clearance issues. I am just wondering if I clean the knicks up by hand, will that be fine? I just think it's odd that I have it only on two pistons.

[Fastbird]

How big of a cam? May want to compression/leakdown to see if you bent a valve.

Posted from my Rezound

[ZGOBYBY]

Well... I am putting on a new set of heads actually, so the old heads are not being used. I don't know the specs of the cam actually, Specter Werkes built a '99 Z28 for my friend, who passed away last year, and I picked up the heads and cam from his son over the summer last year, from the car featured below.

http://www.superchevy.com/features/c...gtz/index.html

I know it's somewhere in the .53X/.53X ballpark with a 112 LSA.

[Fastbird]

That cam should have NO ptv issues anywhere.

Posted from my Rezound

[ZGOBYBY]

My timing chain was pretty worn out as well, I'm wondering if the slack caused this possibly.