Pistons hit valves
Thread Starter
On The Tree
Joined: Sep 2014
Posts: 184
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From: Albany,OR
Pistons hit valves OK so 99Ls1 was burning alot of oil so I took it apart was going to do a lite hone replace rings and valve guides.I decided to put a cam in.(I have all ready ordered the cam and have it ) so the motor is apart and piston were really dirty did not think much of it and then I started to clean the piston and noticed my valves have hit the pistons figured Ok I will replace them and the heads but now I am going to be starting school in a couple months (Sam racing) and need to move half way across the country and need the car back and running.so I need help buying a new set of pistons that are going to clear the new can lift the cam (vrx4) and what to do as far as heads would it be cheaper to buy new used heads or repair mine ?
Last edited by mngoos; Sep 26, 2015 at 01:13 AM.
Launching!
Joined: Apr 2015
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Actually, I've seen worser sentences. You didn't say how soon you had to have it back together. Two weeks or two months - makes a big difference. If talking weeks, then you might want to look for a replacement engine than can be swapped out in a couple of days. What you're saying about this engine is going to take some time to get running again. There is a lot of down time waiting for parts and machining. Good luck with it!
Sorry, you did say a couple of months. You'll still have to hurry to make it!
Sorry, you did say a couple of months. You'll still have to hurry to make it!
Actually, I've seen worser sentences. You didn't say how soon you had to have it back together. Two weeks or two months - makes a big difference. If talking weeks, then you might want to look for a replacement engine than can be swapped out in a couple of days. What you're saying about this engine is going to take some time to get running again. There is a lot of down time waiting for parts and machining. Good luck with it!
Sorry, you did say a couple of months. You'll still have to hurry to make it!
Sorry, you did say a couple of months. You'll still have to hurry to make it!
if you plan on running the same cam and youre having ptv clearance problems. you will need to either fly cut or buy aftermarket pistons
Thread Starter
On The Tree
Joined: Sep 2014
Posts: 184
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From: Albany,OR
OK I fixed some of my sentencing so was rushing it was on break at work and yes the motor was completely stock and I will admit I use to drink and drive alot and probably drove really bad I am paying for it now ( been clean for over two years now )and I have five months tell I move but I also need to save up some money to move thanks
Last edited by mngoos; Sep 26, 2015 at 02:56 AM.
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Teching In
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The valve depression markings on your ceramic alloy pistons is a result of over revving your engine, you were going too fast when you shifted down and the valves were "slung" into the piston, exceeding the force the valve springs have to bring them back up in time (and mechanically over-riding the 6k rev limit). These pistons will run completely fine in your engine unless they are damaged far beyond what we normally see.
Congrats on the sobriety, drinking and driving is bad enough, in an LS1 its a signed title to death. I wish many of us didn't know this as well as we do.
That said, if you drink, at least take an Uber or something, please, and congrats on sobriety keep it up.
The repair.. You have ceramic-alloy pistons that will not be damaged by a little valve slap. Your 7.4" (if I recall) push rods will bend six ways to sunday (and cause serious problems) before your pistons gets a sense any action is occurring.
Is your objective to have a very fast car, or to have a car that's put together and runs? Also, don't reuse stretching bolts if possible, use quality new gaskets, keep it clean, use proper methods, etc. That's important.
PM me if you need anything else, but school up and post pics of those pistons and do it ahead of time b/c u may well have finishing issues. Best luck
Congrats on the sobriety, drinking and driving is bad enough, in an LS1 its a signed title to death. I wish many of us didn't know this as well as we do.
That said, if you drink, at least take an Uber or something, please, and congrats on sobriety keep it up.
The repair.. You have ceramic-alloy pistons that will not be damaged by a little valve slap. Your 7.4" (if I recall) push rods will bend six ways to sunday (and cause serious problems) before your pistons gets a sense any action is occurring.
Is your objective to have a very fast car, or to have a car that's put together and runs? Also, don't reuse stretching bolts if possible, use quality new gaskets, keep it clean, use proper methods, etc. That's important.
PM me if you need anything else, but school up and post pics of those pistons and do it ahead of time b/c u may well have finishing issues. Best luck
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Verdad Gallardo OK so 99Ls1 was burning alot of oil so I took it apart was going to do a lite hone replace rings and valve guides.I decided to put a cam in.(I have all ready ordered the cam and have it ) so the motor is apart and piston were really dirty did not think much of it and then I started to clean the piston and noticed my valves have hit the pistons figured Ok I will replace them and the heads but now I am going to be starting school in a couple months (Sam racing) and need to move half way across the country and need the car back and running.so I need help buying a new set of pistons that are going to clear the new can lift the cam (vrx4) and what to do as far as heads would it be cheaper to buy new used heads or repair mine ?
You might want to just leave the old cam in there until you get to SAM. Once the cam is in, you're ging to need a tune too which is another expense. Houston has some really good tuners here, and Pat G is just a couple hours away in Victoria.
But if you decide to swap in the cam now, you can probably pickup a cheap flycutting tool that will cut the releifs in the pistons. That way you don't have to buy new pistons, which usually require a professional hone job. If you're going to start SAM, you may want to build something there when you can machine it and do it right, and have some guidance from some really knowledgeable people.
The guides in these heads usually don't wear too bad, but if you replace them, you're going to need a valvejob too. Again, something you would want to wait until you get to SAM to do yourself with some of the valvejob cutters they use.
Congrats on the two years sober BTW. You should be proud of that!
Thread Starter
On The Tree
Joined: Sep 2014
Posts: 184
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From: Albany,OR
Well I really wish I could wait tell I get there buy my 99 camaro is my daily driver and I will have to have a car when I get there. But my block has all ready been honed the cam kit is all ready here now my plan was to get forged rods and pistons and change the heads to 799 heads but now I am have a time frame and short on money now I am just trying to get it back to driving I can't afford to take two cars down to Houston I live in Oregon
Thread Starter
On The Tree
Joined: Sep 2014
Posts: 184
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From: Albany,OR
So what I am thinking is order some flat top piston for about $250 and I don't know what to do with the heads I ordered the vengeance racing cam kit so I got new springs push rods everything as for the tune I was going to do mail ordered for now (tune by frost) and will do a dyno tune when I get there
So what I am thinking is order some flat top piston for about $250 and I don't know what to do with the heads I ordered the vengeance racing cam kit so I got new springs push rods everything as for the tune I was going to do mail ordered for now (tune by frost) and will do a dyno tune when I get there
TECH Fanatic
Joined: Jul 2007
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From: Wilmington, De
If your valves were hitting the pistons in a stock engine, then I'd say you were experiencing valve float, which most likely was from high RPMs, weak valve springs, and possibly a stretched timing chain.
Honestly, you will most likely be able to run the stock pistons regardless of the valves hitting them. I've seen factory pistons with some deep gouges from contact run without issue, and I mean contact to the point we thought the pistons were flycut .060". Since you didn't notice the marks until you cleaned the tops, I'm assuming they aren't anything much more than little dings in the surface of the piston.
Honestly, you will most likely be able to run the stock pistons regardless of the valves hitting them. I've seen factory pistons with some deep gouges from contact run without issue, and I mean contact to the point we thought the pistons were flycut .060". Since you didn't notice the marks until you cleaned the tops, I'm assuming they aren't anything much more than little dings in the surface of the piston.