Groove on top of piston?
11-06-2012, 06:25 PM
#1
Groove on top of piston? Guys, I am currently rebuilding an LS1 & while I was cleaning the pistons up I noticed a small groove on the top of some of them(#2, 4, & 5..so far, havent cleaned the rest). Below I will post a picture of it with a circle around the groove, hopefully everyone can see it.
My question is, what is the groove? Is it going to be a problem? Is it caused by something that could damage the engine?
While I am rebuilding the bottom end, I am installing an MS3 cam, ported LS6 heads, LS6 intake, & American Racing LTs.
Well, onto the pic. Let me know something guys, Thanks in advance.
Brenton
My question is, what is the groove? Is it going to be a problem? Is it caused by something that could damage the engine?
While I am rebuilding the bottom end, I am installing an MS3 cam, ported LS6 heads, LS6 intake, & American Racing LTs.
Well, onto the pic. Let me know something guys, Thanks in advance.
Brenton
11-06-2012, 07:23 PM
#4
no, the engine was stock before the rebuild. Bought the engine/transmission/etc from a buddy out of his wrecked z28. it only had 63k miles on it when he wrecked it.
Will it be okay to use the pistons since ill be going with new heads, valves, etc? or am I pretty much fucked?
Will it be okay to use the pistons since ill be going with new heads, valves, etc? or am I pretty much fucked?
11-06-2012, 07:25 PM
#5
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no, the engine was stock before the rebuild. Bought the engine/transmission/etc from a buddy out of his wrecked z28. it only had 63k miles on it when he wrecked it.
Will it be okay to use the pistons since ill be going with new heads, valves, etc? or am I pretty much fucked?
Will it be okay to use the pistons since ill be going with new heads, valves, etc? or am I pretty much fucked?
11-06-2012, 07:31 PM
#6
NightmareTA, I agree.. it is odd that the stock cam was having problems with piston to valve contact. Maybe it was due to a missed shift or a 3rd gear to 2nd gear wot shift on accident. I dont know how my friend drove it really.
When I go back in with the MS3 cam I will be going with some PRC .650" valve springs so that should be sufficient. Ill be using stock rockers with the Comp Cam Trunion Upgrade, in case any of this matters.
When I go back in with the MS3 cam I will be going with some PRC .650" valve springs so that should be sufficient. Ill be using stock rockers with the Comp Cam Trunion Upgrade, in case any of this matters.
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11-07-2012, 09:11 AM
#12
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If it makes you feel any better, I had similar valve marks on every single piston in my turbo 5.3. Had to rip it apart and replace a piston with a cracked ringland, which is how I originally noticed them. Slapped it back together with the fresh piston and just took it for a rip ride last night. Runs great, and that's with 11 PSI and 563 rwhp. I'm sure your pistons will last a long long time on an N/A motor.
11-07-2012, 12:05 PM
#13
Okay guys now I have another question. On the #6 piston I noticed a little mark/slash on the side of it. Below is a picture. Is this something I should worry about? I can feel it just slightly when running my finger nail around the piston.
Last edited by Coonass350; 11-07-2012 at 09:46 PM.
11-07-2012, 12:24 PM
#14
That little groove in the first pic is just fine. I accidentally dropped it into 2nd gear at 80+mph in my 2000 C5 when is was bone stock at 34k miles on the odometer. When disassembling the motor, every piston had fairly large grooves from the intake and exhaust valves, most of the valves and pushrods were bent, if not all. Some pushrods were rainbow shaped. I intially thought the pistons were junk. After having them inspected, they were all fine, no cracks. Just had to flycut reliefs in them and clean them up. Those pistons have been working perfectly fine for 9k miles at 430whp.
11-07-2012, 01:11 PM
#15
That little groove in the first pic is just fine. I accidentally dropped it into 2nd gear at 80+mph in my 2000 C5 when is was bone stock at 34k miles on the odometer. When disassembling the motor, every piston had fairly large grooves from the intake and exhaust valves, most of the valves and pushrods were bent, if not all. Some pushrods were rainbow shaped. I intially thought the pistons were junk. After having them inspected, they were all fine, no cracks. Just had to flycut reliefs in them and clean them up. Those pistons have been working perfectly fine for 9k miles at 430whp.
11-07-2012, 05:56 PM
#17
Yes this is the original block it came out of. I havent checked the cylinder yet for any roughed up spots but will in just a few minutes.
11-07-2012, 07:00 PM
#18
I just went out and looked that cylinder over. There is a very very faint mark on one side. I slid the piston in just to see about where the mark was and they are in the same spot. So I dont know what to do. Want to use the piston but dont want it to cause a problem. What is the worst that could happen?
I mean when I slide the piston in, it didnt seem to be rough feeling. The mark on the piston is faint and can barely tell that its there with your fingernail & the same with the little mark on the cylinder.
Before my friend wrecked the car he didnt have trouble with the engine, it ran strong.
I mean when I slide the piston in, it didnt seem to be rough feeling. The mark on the piston is faint and can barely tell that its there with your fingernail & the same with the little mark on the cylinder.
Before my friend wrecked the car he didnt have trouble with the engine, it ran strong.
