C

cduck28z

I'm New Here
Hey guys, I'm looking at an airplane right now that has lived in the Chicago area it's whole life. Always hangered with exceptional build quality. O-360 compression is great (78,78,75,77), the motor is clean, and runs smooth. The owner/builder is of age and just hasn't flow it, like almost at all, in 25 years. It was rebuilt in 1999 after the original log books were lost and has less than 200hr on it currently.

What are come precaution or steps I can take to minimize my risk with this older rebuild? I know Lycoming motors have the potential for rust to pit the cam shaft, but a scope isn't going to be able to make it down there?

Thanks in advance for all the help from the community!
 
If you do a search you can find a lot of discussions on this very topic.
My recommendation is buy it with consideration that it will need to be rebuilt sooner than later, and possibly really soon. Change oil often and do your filter inspections. If it isn’t making metal, keep running it and watching.
There is only so much that can be discerned with an inspection.
 
Beyond just compression testing, I'd want a thorough evaluation by a really good airplane engine guy, including oil analysis and borescoping, although you can't really evaluate for corrosion on the camshaft with a borescope. Airframe also needs a thorough inspection. Unless you're an A&P, you will need professional guidance on an airplane that hasn't run in 25 years.
 
cduck28z said:
Hey guys, I'm looking at an airplane right now that has lived in the Chicago area it's whole life. Always hangered with exceptional build quality. O-360 compression is great (78,78,75,77), the motor is clean, and runs smooth. The owner/builder is of age and just hasn't flow it, like almost at all, in 25 years. It was rebuilt in 1999 after the original log books were lost and has less than 200hr on it currently.

What are come precaution or steps I can take to minimize my risk with this older rebuild? I know Lycoming motors have the potential for rust to pit the cam shaft, but a scope isn't going to be able to make it down there?

Thanks in advance for all the help from the community!
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You are right a scope isn't able to make it down there. BUT, it probably is able to make it UP there by removing the sump you can see the back three lobes on the cam. I know as I have done this on a 35 year old 0-360 engine that had only run 4.1 hours taxiing around before ""removal"" and ""storing"" by a furnace or dry shop. IT showed no signs of rust and now has 75 hours on it this summer as proof age isn't always the factor.
I did an engine swap in April for different reasons.
Another factor is a lot of engines reworked around that time got the not so great Channel chrome cylinders as mine did. I burns a quart in 7 hours. NO corrosion, just oil consumption for the life of the engine.
But you said the engine has 200 hours on it so that changes the question. Where was it stored, parked, hangered? That's the big one.
The airframe and that is another question, But you asked about the engine. And if it has a CS prop that needs looking at to.
My luck varies FIXIT
 
JonJay said:
Oil analysis work on trends. It won’t tell you much until a base line is established over several tests.
The labs actually will tell you this when you get your first report.
One of the many reasons I don’t value them. Lots of “false” positives, or is that negatives?
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I agree that the likely high false negative rate of one-time oil analysis might limit diagnostic accuracy, but the false positive rate is going to be much lower. I think a one-time analysis of oil can be useful in getting an idea of engine health, just as dissection of an oil filter can be useful. Especially true when done with other evaluations like checking the oil filter, borescoping, and compression testing. Not optimal by itself, I agree, but if he runs the engine for awhile and sends in an oil sample, and Blackstone writes back "holy ***!!!" then that might provide sufficient impetus to go further and actually look at the camshaft before writing a check for an engine with such a dubious history.
 
Pretty easy to pull a couple cylinders and actually look at the cam and lifters.

A days worth of effort tells a lot.

Accessory case is a bit harder in situ, but I’d be most concerned with cam/lifter condition.
 
Pull a cylinder during prebuy…if not, negotiate an overhaul in the price. You can overhaul a Lyc for about 15k if you do it yourself
 
First question to ask "When was the last time that the engine ran"?

Second question to ask "How comfortable am I with putting my butt (or that of a friend/relative/significant other in an airplane with this engine)"

If you don't like either answer, time to open up the engine for an inspection.........peace of mind........future confidence in the engine.

My $.02 this afternoon.
 
I just got a IO-540 that has 300 hours on it SMOH in 2019. Part of the deal was to pull all the cylinders, send them to LyCon for port and polish, light hone and new rings. The engine was stored in desert conditions and pickled, still one cylinder had very light corrosion. The rest of the engine looks great.
 
I had a angle valve IO-360 on my Mooney 201 and did oil analysis every 50 hours. I cut open every filter. Analysis showed good levels that would be expected of a good running engine.
I noticed a decline in power climbing, seemed to not be what it had been. I decided to pull # 3 cylinder and take a look around and found the front 2 lobes of the cam were worn down 1/8". Oil samples showed nothing.....I guess the particles were too big to show up ( I found camshaft shavings that looked like drill shavings from a drill press in the sump on disassembly).
 
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