Cylinder Wall Wear?

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Lakeeffect

Lakeeffect

Drive Fast , Take Chances
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I was wondering what would be acceptable bore wear on a stock 340? I am on a tight budget and want to reuse the old pistons. Thanks FABO!
 
You need to measure the bores individually with a dial bore gage. Then mic the pistons properly. Then see if the clearance is within spec or not, or even close. However, the most important wear occurs on the insides of the top ring land where the ring has to seal. You can have acceptable piston to wall clearance and still have junk pistons.
 
moper said:
You need to measure the bores individually with a dial bore gage. Then mic the pistons properly. Then see if the clearance is within spec or not, or even close. However, the most important wear occurs on the insides of the top ring land where the ring has to seal. You can have acceptable piston to wall clearance and still have junk pistons.
Click to expand...

Well I am putting a 340 together with spare parts. Stock Bore with Cut down TWS's I only asked because the Machine shop meassured it and said they had between .004 -.005 Wear. They recommended not honing and sticking with the stock bore.
 
It's taper that kills you, more than the overall side clearance. Bear in mind "wear" on either bore or piston leads to wider clearance and piston rock. The probelm is the ring cant seal well to the bore if the piston's rocking around and at TDC that can be a problem. Have them measure the ring to ring groove clearance and compare to piston manufacturer spec.
 
Thanks Moper. I guess std TRW pistons are .005 under. The block is between .004-.006. Damn. Trying to use up old parts laying around. Not working out so good.
 
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