Piston Rings

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bobscuda67

bobscuda67

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Hey people! My 340 engine, with 800 miles on it, had a really small oil leak between the head and block that it's had since it was rebuilt years ago. Last fall I took the heads off to replace the head gaskets. I was planning to use some MLS gaskets but the deck was way to ruff, but the heads are really smooth. So out comes the short block and I took it to the machinist who prepped my heads. He was amazed that it didn't leak worse than it did. The guy that did the short block is getting old and won't buy new machine tools and his quality has gone downhill. Anyway the block was .008 different front to back and the rod big ends were all over the place on the balance. He had to cut .015 off the deck to get it flat and square. Of course the pistons need the be milled now to be at zero deck, and balance the thing again.

This thing is going to cost me a lot more than a head gasket swap. So to try and save some money he cleaned it in his aluminium tank so I can reuse the cam bearings and soft plugs. I will replace the bearings even though there in like new condition, that's a given. But, the rings are Total Seal 2nd gapless and also in great condition. Can I reuse them or would that be stupid, especially if they don't seal. If not, what rings would you use for a 5/64's ring land piston? Not much choice for a 4.070 bore anymore.

Sorry for the long post but I have to decide this week what to do.
 
Those are expensive rings.if they were sealing and you didnt hone it i would use them again.but not if you had the block honed....
 
first if they resurfaced the block metal shaving probably went down the oil holes into the cam bearings ,so I don't think you can get it out without removing the cam bearings.
 
I would remove the oil galley plugs and take it to a local do-it-yourself car wash and blast the oil galleys out with a pressure hose.

Also check the cam bearing oil hole alignment by straightening out a wire coat hanger and sticking it through the oil feed holes in the top of the main bearing saddles and also poke it through the oil feed holes to the head. this will help make sure that the holes are not plugged and the cam bearings are lined up when you see the wire poking through as you look through the cam tunnel. The holes for the cam bearings should not be blocked more than half way (half way overlapped or less) for misalignment.
 
80fbody said:
Are you sure you need to mill the pistons?
Click to expand...

Well, they were at zero before with a .040 head gasket. Perfect quench. Now they'll be .015 out of the hole. Could add a thicker head gasket but then the quench isn't near as good.
 
Will check cam bearing alignment, but the motor had very good oil pressure,
65 psi at a hot idle with 10w30 and a stock pump.
The block will have a plug installed at the shaft oiling hole as it has Magnum heads and the hole isn't used. I think that's where the oil drip started at.
 
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