John Courte
Well Known Member
A couple of years ago, I bought an O-360-F1A6, which, according to the seller, sat pickled from 2000 to 2008, when I bought it. No reason to disbelieve the pickling, there was clean oil running out of everything when he dropped it off. I pulled a plug and saw no corrosion in the cylinder barrel, but was advised to pull a jug and have a look at the camshaft lobes, etc.
That was 2008. I've had it sitting upside down on an engine stand (modified auto stand) full of oil since then, and it's now the time in the project to finish the the FI conversion process.
Yesterday, I pulled the #3 cylinder off. I did it as carefully as I could, supporting the con rod as I took it off so it wouldn't bash the case. After much effort and some dowel-hammering (backing up the piston so no side loads went on the bearing), I got the wrist pin out and got the piston off as well. They're the press-fit Superior type.
The amount of stuff in the cylinder was a little distressing. Not corrosion, but gray scale and brown crud. Nothing that stuck to my magnetic probe, anyway. My plan was always to replace all 4 cylinders with new or overhauled ones, since the last two compression checks in the logbook showed low 70's, then mid 60's. I suspect the plane it came from was not flown much later in life. I also searched the FAA's incident reports and found nothing for the N number of the aircraft the engine came from. In a couple of days, I'll cut open the oil filter and look for metal, but none was found as of the last logbook entry at 951 hours.
The good news is that I detected no corrosion on the cam lobes and they passed the 'fingernail test' according to sacskyranch. I didn't find any corrosion on any of the other internal surfaces I could access either, and no visible spalling of the cam followers (those little mirrors on telescoping rods are invaluable) As part of the FI conversion, I also removed the backwards facing sump, which gave me a good look inside the accessory case. I found no corrosion there as well.
By the way, upside down with the sump off is probably the easiest way to change a fuel pump I can think of. After scraping off the old gasket material with repeated application of gasket remover and elbow grease, I installed the high-pressure fuel pump.
Why am I doing this now, instead of right before i'm ready to hang the engine? I'm doing it because the way forward is planned largely on whether or not I found a rusty camshaft and other corroded internals. This is the nodal point of both budget and project planning. I can't plan interior and panel until I know what my powerplant is going to cost me, and I'd rather have a basic plane that flies instead of a fancy one that doesn't.
s far as my mechanical aptitude goes, I've torn down and reassembled V8's, a Harley Evo 1200, various 2-strokes, and a couple of outboards. I'm not very experienced with aircraft engines, but my research skills are decent, and I have the overhaul documentation and parts catalog. That said, I don't plan on tearing this engine down myself any further, but I think I can handle the FI conversion and cylinder replacement.
At this point, I'm working on removing the old gasket from the sump flange. I guess the question is, do I get new or overhauled cylinders? And is this a race against time to get this engine repickled before things start to corrode? I live about 3.5 miles from the Pacific Ocean, but the marine layer has been kind to us lately.
That was 2008. I've had it sitting upside down on an engine stand (modified auto stand) full of oil since then, and it's now the time in the project to finish the the FI conversion process.
Yesterday, I pulled the #3 cylinder off. I did it as carefully as I could, supporting the con rod as I took it off so it wouldn't bash the case. After much effort and some dowel-hammering (backing up the piston so no side loads went on the bearing), I got the wrist pin out and got the piston off as well. They're the press-fit Superior type.
The amount of stuff in the cylinder was a little distressing. Not corrosion, but gray scale and brown crud. Nothing that stuck to my magnetic probe, anyway. My plan was always to replace all 4 cylinders with new or overhauled ones, since the last two compression checks in the logbook showed low 70's, then mid 60's. I suspect the plane it came from was not flown much later in life. I also searched the FAA's incident reports and found nothing for the N number of the aircraft the engine came from. In a couple of days, I'll cut open the oil filter and look for metal, but none was found as of the last logbook entry at 951 hours.
The good news is that I detected no corrosion on the cam lobes and they passed the 'fingernail test' according to sacskyranch. I didn't find any corrosion on any of the other internal surfaces I could access either, and no visible spalling of the cam followers (those little mirrors on telescoping rods are invaluable) As part of the FI conversion, I also removed the backwards facing sump, which gave me a good look inside the accessory case. I found no corrosion there as well.
By the way, upside down with the sump off is probably the easiest way to change a fuel pump I can think of. After scraping off the old gasket material with repeated application of gasket remover and elbow grease, I installed the high-pressure fuel pump.
Why am I doing this now, instead of right before i'm ready to hang the engine? I'm doing it because the way forward is planned largely on whether or not I found a rusty camshaft and other corroded internals. This is the nodal point of both budget and project planning. I can't plan interior and panel until I know what my powerplant is going to cost me, and I'd rather have a basic plane that flies instead of a fancy one that doesn't.
s far as my mechanical aptitude goes, I've torn down and reassembled V8's, a Harley Evo 1200, various 2-strokes, and a couple of outboards. I'm not very experienced with aircraft engines, but my research skills are decent, and I have the overhaul documentation and parts catalog. That said, I don't plan on tearing this engine down myself any further, but I think I can handle the FI conversion and cylinder replacement.
At this point, I'm working on removing the old gasket from the sump flange. I guess the question is, do I get new or overhauled cylinders? And is this a race against time to get this engine repickled before things start to corrode? I live about 3.5 miles from the Pacific Ocean, but the marine layer has been kind to us lately.
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