inside cylinder oil drain hole

IN bore drain adequate if other holes blocked?

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inside cylinder oil drain hole


Post by fjallan »

I have 1978 cylinders and heads on my 1967 Flh. The cylinders have the oil drain holes within the bore. The crank case has a single drain hole directly behind the front lifter block. That single drain hole is blocked by gasket and the cylinders have no corresponding hole. Will the IN-Bore drain alone adequately drain the oil? Is this Normal? Thank you

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Re: inside cylinder oil drain hole


Post by RooDog »

The hole in the front cylinder base adjacent to the lifter blocks block is an oil passage for pressurized oil to feed the hydraulic lifters. It is NOT a drain hole. The oil drains are on the left side of the cylinders, about 3/16" diameter and drain oil through the cylinder wall into the bore. For strokers these holes must be relocated lower in the jugs so as to not feed oil upon the piston rings. Whatever year heads and/or jugs you use should make no difference as to the oiling scheme....
Base Gasket Blocked Oil Hole.jpg
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