Piston to wall clearance ??
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Joined: Jun 2003
Posts: 55
From: Montreal, Quebec, Canada
Piston to wall clearance ??
I'm not sure If I should have posted this in the N20 forum or not....
I bought a set of JE/SRP forged pistons for my 383 buildup. On the sheet supplied by srp it says that the normal operating clearance is .002-.0025 .
It also states that some applications such as marine, DRAG RACE, NITROUS and forced induction may require additional clearance, .001-.003 .
This is a .030 overbored LT1 block, for my daily driver, wich will see regular trips to the drag strip and some nitrous (100hp)
My question is what do I need to set the clearance at ?
Thanks for time and responses !!
Charles
I bought a set of JE/SRP forged pistons for my 383 buildup. On the sheet supplied by srp it says that the normal operating clearance is .002-.0025 .
It also states that some applications such as marine, DRAG RACE, NITROUS and forced induction may require additional clearance, .001-.003 .
This is a .030 overbored LT1 block, for my daily driver, wich will see regular trips to the drag strip and some nitrous (100hp)
My question is what do I need to set the clearance at ?
Thanks for time and responses !!
Charles
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Joined: Oct 2002
Posts: 255
From: Nashville
I prefer to set my cylinders about .0005 looser than the standard size. So if they recommend .0025 then I set it up at .0030. There are two old sayings in the machine shop biz - looser makes more power - and - if you set the pistons a little loose, only you will know, if you set the pistons a little tight, the whole world will know!
Also I HIGHLY recommend using a torque plate when honing. To see the difference all you have to do is measure the bores with a dial bore gauge with and without the plate installed and you'll never go back!
Also I HIGHLY recommend using a torque plate when honing. To see the difference all you have to do is measure the bores with a dial bore gauge with and without the plate installed and you'll never go back!
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Joined: Oct 2001
Posts: 1,462
From: smog zone adjacent to a great lake
Re: Piston to wall clearance ??
Originally posted by charles94ta
On the sheet supplied by srp it says that the normal operating clearance is .002-.0025.
On the sheet supplied by srp it says that the normal operating clearance is .002-.0025.
Registered User
Joined: Oct 2002
Posts: 255
From: Nashville
A 100 shot of nitrous is not a lot. Like I said I usually set the Pistons to wall clearance at .003 with an SRP piston but if you are concerned about it and may want to run more spray in the future then open the clearance up to .0035 or even .004. The SRP pistons don't require as much clearance as the regular JE or most other brand pistons because of their higher silicon content that reduces the amount they expand in the bore.
Also for ring gap if you are going to spray it some then I would set it at .020 on the top ring and .016 on the second.
Also for ring gap if you are going to spray it some then I would set it at .020 on the top ring and .016 on the second.
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