Lionclaw
Well Known Member
I have an O-320-H2AD engine on my 9A. I just finished a rebuild on my engine to replace a bad cam/lifters and to try to seal some pesky oil leaks. After doing a 15-minute run today to test my new single mag (51360-46 FTW!), I found oil splattered on the firewall. Upon close inspection it seemed to be coming from the first junction in the exhaust. There was also oil dripping from the end of the exhaust.
My first thought was that I had perhaps busted the oil ring on one of the pistons. I did a compression test and got 79/80 on that cylinder. Afterwards I also found quite a bit of oil had pooled in the air box.
It would seem to me that the oil in the airbox would preclude the possibility of this being a broken ring. Another symptom I've noticed is a clicking sound coming from the valve covers. I removed the bottom plugs and spun the prop by hand for about 30 seconds, then was met by a deluge of oil when I removed a few of the valve cover screws.
Anyone have any thoughts? Right now I'm leaning towards some kind of blockage in the oil drain back line, causing the rocker area to become pressurized with oil, and it being pushed through the valve guides. As a side thought, does anyone have any part numbers for valve stem seals that will work? I see Graham has some on his engine, but I'm having trouble locating some that are the right size...
My first thought was that I had perhaps busted the oil ring on one of the pistons. I did a compression test and got 79/80 on that cylinder. Afterwards I also found quite a bit of oil had pooled in the air box.
It would seem to me that the oil in the airbox would preclude the possibility of this being a broken ring. Another symptom I've noticed is a clicking sound coming from the valve covers. I removed the bottom plugs and spun the prop by hand for about 30 seconds, then was met by a deluge of oil when I removed a few of the valve cover screws.
Anyone have any thoughts? Right now I'm leaning towards some kind of blockage in the oil drain back line, causing the rocker area to become pressurized with oil, and it being pushed through the valve guides. As a side thought, does anyone have any part numbers for valve stem seals that will work? I see Graham has some on his engine, but I'm having trouble locating some that are the right size...