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oil in exhaust

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abert51
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Posts: 64
Joined: Fri May 30, 2008 10:52 am
Location: CENTRAL MASSACHUSETTS

oil in exhaust

Post by abert51 » Fri Oct 19, 2012 2:57 pm

1965 305 scafter the rebuild it's running on one clyendar. left cylinder is not firing. Black oil dripping out of the left exhaust pipe where it enterS th head. Possible reasons for this calamity? did I forget the two little o rings that go on the fronT left of the cylinder base at the long studs? they are small, about 11X2 mm o-rings. Can't be leaky valve seals because in 1965 the CL77 didn't have any. How does the oil get from the bottom end up through the clyinders and heads to the rockers. Somehow oil is getting into the left jug, fouling the plug and keepping the cylinder from firing properly or not much a all. Any help out therel..Thanks for any response or suggestions. will check compression first just to see if there is a difference. where can I get new head gasket and the 2 little o-rings?

48lesco
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Joined: Tue Mar 06, 2007 1:45 pm
Location: Olmsted Twp, Ohio

Post by 48lesco » Fri Oct 19, 2012 3:50 pm

Oil gets to the head through the two front outer cylinder studs. Beside the head gasket, there are two important parts in there between the top of the cylinder block and the head. They are the 11x16 "knock pins" and the o-rings that you mentioned.

OEM head gaskets are on ebay now for $25 and the o-rings are available at your Honda dealer. The knock pins are harder to find but a forum member may have a couple extra. The o-rings go around the knock pins and seat in the big holes in the head gasket.

Sounds like a lot of oil, and it would not usually leak into the combustion chamber from that point, it usually leaks out to the outside. I'd get in there and make sure there aren't any issues with valve guides, etc.
-48

OldStan
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Joined: Wed Jul 14, 2010 5:33 pm
Location: Galt, California

Post by OldStan » Fri Oct 19, 2012 9:23 pm

Make sure the oil isn't running off the fins on the head onto the exhaust pipe. A leaking cam cover on the side of the head can do that. Might be a separate problem from the cylinder not firing.
63 CA78

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