walkman
Well Known Member
I ended up pulling the cylinder. It seemed to be leaking past the rings. After I got it off I took a bunch of pictures. Here
The valves and seats aren't great but don't appear to be too horrible. The cylinder walls had hone marks still (900 hour engine) but what appears to be some light scuffing in one area. The rings don't look too bad, are intact, and move freely in their lands. They aren't coked up except the oil control ring is a little. They aren't very sharp any more, but its a 900 hour engine. No sign of spalling on the cam lobes.
However I found some things on the piston I didn't like. First, the wrist pin won't budge. Piston rotates just fine, but it ain't coming out. Need to figure out how to persuade it without putting side load on the bearing. The biggest issue with the piston is some heavy scoring around about 1/5 of the circumference. Its very rough to the fingers, you can feel the grooves. They are pretty deep. Possible signs of uneven heating on the piston skirt.
Last time I pulled a jug it was an O-320 (this is an XP-360) but I recall the exhaust valve having a convex face. This has a concave face. Am I mis-remembering?
Let me know what you think.
The valves and seats aren't great but don't appear to be too horrible. The cylinder walls had hone marks still (900 hour engine) but what appears to be some light scuffing in one area. The rings don't look too bad, are intact, and move freely in their lands. They aren't coked up except the oil control ring is a little. They aren't very sharp any more, but its a 900 hour engine. No sign of spalling on the cam lobes.
However I found some things on the piston I didn't like. First, the wrist pin won't budge. Piston rotates just fine, but it ain't coming out. Need to figure out how to persuade it without putting side load on the bearing. The biggest issue with the piston is some heavy scoring around about 1/5 of the circumference. Its very rough to the fingers, you can feel the grooves. They are pretty deep. Possible signs of uneven heating on the piston skirt.
Last time I pulled a jug it was an O-320 (this is an XP-360) but I recall the exhaust valve having a convex face. This has a concave face. Am I mis-remembering?
Let me know what you think.