Take a look at these pics - need opinions

I want to post this here to get some feedback on what you see.

The main complaint was the #2 cylinder was getting oil fouled. This is from a 6 cylinder jeep engine (258ci).

The pistons are 40 over bore and the crank is 10 10 as I understand it.

The cylinder walls are very smooth with no ring ridge. The crank is also very smooth. This engine was supposidly rebuild about 40k miles ago. I not sure what to think on it but I'm concerned to invest in fixing it. Need your opinions.

Thanks,

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Reply to
William Oliveri
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William, Did you do a Leakdown test or a Compression test before you tore down the engine? A leakdown test would have told you all you needed to know. The problem could have been as simple as bad valve guide seal without the need to tear the engine apart. The cylinders look well worn in as no crosshatching is visible, the only way to tell if a cylinder bore is straight is to take several bore diameter measurements along the length of the cylinder. It could be the oil control rings, see if you can find the specs for the allowable gap required, shove one down the bore with the piston and check the gap, but odds are since the other cylinders are not having the same oil control problems my bet is on either the valve seal or valve guide. The wear on the rod and main bearings look a little excessive for 40k miles, your past the babbitt and into the base already, even stranger is the bearing on the main bearing cap doesn't look like diameter is concentric, if you notice there's no wear down about 1/4" to 1/2" from the ends of the bearing.

Good Luck! John

Reply to
Bowshock

Compression test on this engine was 150 psi across all cylinders. Leak down was below 10% warm. The valve seals had be recently replace and double checked. The valve guide was checked by a machinist and determined to be in fine condition.

Reply to
William Oliveri

Good compression doesn't mean good oil control rings.

-- Elbridge Gerry, of Massachusetts:

"What, sir, is the use of militia? It is to prevent the establishment of a standing army, the bane of liberty. . . Whenever Government means to invade the rights and liberties of the people, they always attempt to destroy the militia, in order to raise a standing army upon its ruins." -- Debate, U.S. House of Representatives, August 17, 1789

Reply to
AZGuy

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