Don't know where you are but we used to use http://www.zephyrengines.com/
Flew/purchased/sold many Navajos and sent every engine that needed overhaul to them.
Just had my engine done by LJ at ZephrEngines - great company
signature engines at lunken airport in ohio did mine.
My PA 28-180D has 2106 hours on its A4A engine and it's running fine, no excess oil use, and at annual compressions have been in the 70's. Well cared for plane. My mechanic says keep flying until you notice something not right with the engine. However, a friend's mechanic, after hearing about the time on my engine, said I shouldn't fly the plane past 2300 hours. He said I could have a sudden crankshaft failure without warning. Hadn't heard this before.
Would appreciate any comments. Martin
I've never heard of a sudden crankshaft failure just because the engine hits 2,300 hours. During an overhaul, if the old crankshaft is still within spec, it may be reused, or reground and fitted with matching bearings, so I suspect that the crank and many other parts can go beyond 2,300 hrs. On the other hand, there's a reason the engineers spec'd 2,000 hrs. as the TBO.
I've been through (2) engine cycles. If you go beyond TBO, keep close tabs on the engine. My last engine went to 2,200 hrs, and had given me well over a quarter million miles, so it didn't owe me anything. I didn't feel the need to push my luck just to say I got another 100 hrs out of it. I don't put myself or my passengers at risk, so it was time.
I went with a factory rebuilt zero time engine (O-320). At the time (12 yrs ago), Lycoming offered price breaks that put the zero time engine within $900 of a shop overhaul. The new engine has the roller cam and lifters, and since it's coming from the factory, all AD's are complied with. It's smoother and makes better power than my old flat tappet engine when it was new. I don't know if down time is important to you, but a fully assembled engine in a crate will install a lot quicker than the time required for a shop rebuild.
Jim "Griff" Griffin
PA28 - 161
Here's more useful information. If you're a flight school that flies every day your engine will go way past TBO without a problem because it's used a lot. (It can't legally go over TBO, though, so the point is moot). You can legally go over TBO but if you don't fly very often you're taking some risk. How much risk? We don't know how much risk but how much risk is too much in a single engine plane? Your engine isn't guaranteed to fail slowly. It may be a sudden failure. You need to determine how much risk is too much for you. But keep in mind that your passengers haven't been told about the risk of an over TBO engine. Just my thoughts.
Wright Brothers Master Pilot, FAA Commercial Pilot
Aviation Director, Piper Owner Society Forum Moderator and Pipers Author.
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Thanks Jim Griffin and Scott for your helpful comments. I have some thinking to do about an overhaul or zero time engine. We have a good local shop - Bolduc, for a shop overhaul. I'm expecting to pay upwards of $22,000.00 for a rebuild. Am I in the range ?
$22k sounds like a good price. But what does it include? Oil cooler? mags? alternator? new plugs and wiring? New baffling? Check into the details.
Again thanks Griff and Scott. Very helpful information. I'll reach out to the engine rebuilders you recommended Griff. It's a lot of money for me, and good to know more about what I'm getting. Will follow up. Martin