Piston to wall clearance
12-01-2008, 09:27 AM
#11
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75-100 shot at most probably.
Is it possible that the piston is bigger? He never exactly told me the actual piston to wall... he just told me the bore size is 3.910... but what makes me wonder is he keeps saying 3.908 piston (maybe he is just refering to what the bore should be?).
Is it possible that the piston is bigger? He never exactly told me the actual piston to wall... he just told me the bore size is 3.910... but what makes me wonder is he keeps saying 3.908 piston (maybe he is just refering to what the bore should be?).
12-01-2008, 09:48 AM
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Every piston manufacturer has a specific place to measure the diameter. It is typically .5" below the oil ring on the skirt side, but not always. True piston to bore clearance is measuring the piston in relation to it's acutal hole. there are variances in all. I'd measure and match the best combination and run it.
12-01-2008, 09:56 AM
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I am gonna get him to measure the piston to wall I guess and ask him his opinion. If it is infact bored to much over I guess ill just take it back to the orginal machinist and see if he can help me at all... it kinda is his responsibility in a way
12-01-2008, 10:14 AM
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Mahle is saying the biggest they want the bore to be is a 3.908 for a 3.905 piston. This guy said he measured the bore with 2 different tools and got 3.910 on the money.
I think what I may have to do is go with maybe one of these?
http://www.texas-speed.com/shop/item...d=120&catid=38
I think what I may have to do is go with maybe one of these?
http://www.texas-speed.com/shop/item...d=120&catid=38
12-01-2008, 10:20 AM
#15
I'm running Mahle Pistons in a ls1 block too. They called for a .003 clearance, but I had gotten them for standard LS1 bore. My machinist said he had to go to .004 to get the block to clean up. I think he went a little over that on one hole cuz on cold start they clatter for about 30 seconds and one is a bit nosier then the rest, almost a squeaker. It's a little annoying now, but not much I can do about it. Once it runs for 30-60 seconds it all quiets right down and I runs fine. It doesn't smoke or use any oil, just talks to ya a little when I first start it up cold. It's a bit worse when I start it on really cold days up here, like sub 30*.
12-01-2008, 10:39 AM
#16
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I would not run a 4032 piston oversized. I'm sure it would be o.k but, that would be the whole reason I would want to run a 4032.... If your going to have to listen to piston clater, why not buy a stronger 2618 piston?
12-01-2008, 10:58 AM
#17
Mahle makes a 3.907 and 3.908 piston. You also need to let us know if you are N/A or turbo and supercharged or nitrous. Always add more for boost. .005 is a touch big, but I would run it and not worry. One guy already said it, loose is fast.
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