O-360 engine questions (2025)

An acquaintance of mine has asked for an opinion on what to do:

He's a low-time PP, interested in training for his IR, and a few years ago purchased a sweet looking 1966 Cherokee 180 with less than 3000 hours on the airframe and around 700 hours since engine overhaul. It had been based outside on the gulf coast as the former owner wasn't flying much. After buying it, then flying it uneventfully for a couple of years it began making metal and his A&P suggested sending it off for an overhaul at at no name shop in his proximity.

The shop tore the engine down and failed the crank and all four connecting rods. Rust was found inside the apparently hollow crank and on all four connection rods. The owner didn't have any more details on the parts other than they are trash and not to be reused. The owner is strapped for cash and unable to afford the latest quote from the engine shop to do the overhaul. He's stuck with a (to the best of everyones' knowledge) a corrosion free, nice airframe, OK instrumentation (good for learning instruments) without an engine. The final stroke of bad luck was the group hangar housing this plane was in recently sold, and he now has the plane tied down outside entering a Kentucky winter.

First question: has anybody ever heard of all four connecting rods not useable for a rebuild? Sounds a little unlikely to me.

Second question: Are used but serviceable O-360 engines available? The owner claims they're not - at least he hasn't been able to locate any.

Other than my suggestion that he advertise for an engine partner then sell half the plane, or possibly trade his engine-less Cherokee for something less valuable and capable, I'm clueless on ideas to help get him back into the air.....

Rick

First, get ALL the parts back. Even the non-serviceable ones.
Find another shop/rebuilder to evaluate the parts and overhaul.

Yes, used, serviceable O-360s are available. Try Plane Power and various salvage yards.

I would post in the Kentucky regional sub-forum for shop/mechanic recommendations.

Thanks Domenick - will take the liberty of cutting and pasting your response and email it to him.

Rick

Encourage your friend to join this forum and ask questions. We can all offer advice.

I went through a rebuild once - I wasn't financially prepared for it, and the plane sat for about 3 years until I had the cash to buy a new crankshaft ($5800), four new cylinders ($4,000), and various other parts, all totaling about $13,500. I worked alongside a "teaching mechanic" who liked to teach mechanically inclined pilots "how to".

I rebuilt the entire engine, mounted it, connected it all up and it ran beautifully right up to the day I sold the airplane. I learned a ton.

How much is the shop quoting for the parts? There's a tagged O-360 crank on Barnstormers right now for $3900.

While getting a second opinion sounds good, you won't necessarily get a better price somewhere else. Most no-name shops are going to be cheaper than big shops. Collecting a disassembled engine and taking elsewhere might be a bit challenging too, as it sounds like this is a "hands-off" (give the mech the keys) owner?

I would go see the parts and get them to show why the parts failed. If they are truly bad, they should be able to show why easily enough. If they're bad or even marginal, replace them. Even if the airplane is down for a year, it's worth the peace of mind. Engines can stop pretty quick with a broken crank or rod...

thejanitor said:

If it sat for years on the coast, ..... I would be very surprised not to find airframe corrosion also.

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This. I would have a VERY good look at the airframe BEFORE I made any decisions on the engine.

Seems odd to be seeing a hollow crank in an O-360-A4M (standard engine in a PA28-180). But yeah, if you let one of these engines sit a long time in warm salty moist air without doing the pickling process in Lycoming SL 180B, a lot can get rusty in there.

Cap'n Ron said:

Seems odd to be seeing a hollow crank in an O-360-A4M (standard engine in a PA28-180). But yeah, if you let one of these engines sit a long time in warm salty moist air without doing the pickling process in Lycoming SL 180B, a lot can get rusty in there.

Service Letter No. 180 B

Supersedes Service Letter No. L180 A Models Affected To all Owners and Operators of Textron Lycoming Aircraft Engines Engines in aircraft that are flown only occasionally may not achieve normal service life because of corrosion. This occurs when moisture from the air and products of combustion...

www.lycoming.com

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So, when water evaporates, the salt does not evaporate with it. It simply doesn't. I am trying to square that with the OWT of an aircraft near the ocean being exposed to higher levels of salt in the air, which doesn't happen.

Why do we let this OWT persist?

Okay, okay I apologize to the salt! So I (we) lazily and erroneously blamed the salt, when it was really the large body of water, which happened to be salty. If this aircraft sat near the coast, in a humid environment, like the coastal united states, I would expect to see corrosion issues like you reported. I would also expect to see similar corrosion on the leeward side of the great lakes. However, I would expect an aircraft kept or operated very close to the coast to get some sort of salt spray during windy stormy weather.

I do not live or operate in those environments, however I have worked on aircraft from the mid-west and the coast. Coastal aircraft are more likely to have corrosion, and corrosion related problems. I have only seen two engines "come from together to apart" one was a fresh overhaul, the other was in an aircraft from Alabama(ish) that had not flown for several years and was ground run every few months. Threw a rod out of the case after being back in service for 15 hours. Got the prop, spinner cowl and fuselage. Luckily it chose to leave in cruise.

If the OP can find yellow tagged parts, expect them to be 25% of new price, or go buy a mid time engine. I would expect a four cylinder Lycoming to need $11,000 in parts and services at overhaul if you go with new cylinders. Add another $6500 for a new crank. So, a mid time engine can be a good option if you don't have that kind of cash on hand and don't want to finance an engine.

In a hangar is great. Outside is an issue for me. Airplanes tend to leak around doors and windows. On the PA28 family that is over the steel fittings that hold the wings to the fuselage. I have pictures somewhere. I will try to dig them up and post them. They are from a Great Lakes airplane.

Every airplane is different. I just tend to look closer for corrosion on airplanes from those areas. Southwest airplanes get a

lot of dirt, sand, and dust. That has its own unique issues.

TANSTAAFL

All good points and recommendations, I'll pass them on.....

Thanks!

Rick

Cap'n Ron said:

Seems odd to be seeing a hollow crank in an O-360-A4M (standard engine in a PA28-180).

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My 1979 Warrior's original crank was hollow. Lycoming used what they had on hand for a number of O-320 and O-360 engines not destined for constant-speed props. My mechanic and I complied with the terminating procedures in the inspection AD.

Joe Ebert said:

I hangared my plane on the leeward side of Lake Ontario for 9 years. Within 3 miles of the lakeshore.
Never, ever was it ever mentioned that being so close to the lake was detrimental to our aircraft.

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I agree. I think the blanket statement is an OWT. Virtually EVERY GA plane in Western WA is stored within spitting distance of some sort of water body. Saltwater 200 nm long Puget Sound with all its myriad channels and inlets, 16 nm long Lake Washington, and 6 nm Lake Sammamish. Many, many massive rivers snake out of the Cascades into the sound. In virtually every scrape, gouge, and gash, a lake has formed.

Despite what Olympia Brewing has said, I don't think its the water. It may be the absolute humidity which is different from relative humidity. Hot and humid is worse than cool and humid at the very same relative humidity.

Pure evaporation doesn't have salt; indeed one way to purify water is to distill it. But salt must enter air moisture in other ways, because there is plenty of data corroborating increased metal corrosion near the ocean, especially in hot temperatures. Perhaps is it is salt dust becoming airborne through wind action over the ocean.

As for the engine, when my O-320 died a couple of years ago I replaced it with an O-360. I researched many options across several companies, from a local rebuild to swapping the engine. The least expensive was Continental's O-320 replacement overhaul which costs $21k after returning your core. This was about the same price as a local shop overhaul, and it had a better warranty. I opted for the Penn Yann swap to O-360 because their overhaul was one of the least expensive, and they have a solid reputation and the best warranty (3 years or TBO).

Joe Ebert said:

So, when water evaporates, the salt does not evaporate with it. It simply doesn't. I am trying to square that with the OWT of an aircraft near the ocean being exposed to higher levels of salt in the air, which doesn't happen.

Why do we let this OWT persist?

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We had a briefing from a National Weather Service meteorologist last year, who showed us RADAR images of salt in the air. It got there somehow.

I am not an expert on anything weather-related, but presumable NWS meteorologists are.

BTW, since this is a whole lot of men talking about this, if it is untrue, it would be an old husbands' tale. Just sayin'.

So, if we are now considering only salt in the air, virtually the entire country except the coasts and areas adjacent to salt lakes are exempt. As mentioned earlier, water evaporating from salt water does not carry salt, which is why rain is not salty. I think that leaves one mechanism--surf.

Luckily, Puget Sound has very little surf.

We do have wind, and plenty of it sometimes. Wind over water can pick up droplets, which will still be salty since they haven't evaporated. And if they do evaporate while airborne, the salt they contain would be released in the air. If they are small enough, that wind can carry them, similar to dust. That would travel much further than surf. That's just speculation, I am not a meteorlogist.

However, it's a well established observation that metal corrodes faster near the ocean, and the effect goes several miles inland. So there is some phenomena going on, whatever the details.