Help me understand engine overhaul options

[ultrarunner]

I'm looking to purchase my first plane, and I think I have found three that check all the boxes. However, all three of them have had low use over periods of their lives. This has been a consistent theme as I've been looking over the past three months. So I am trying to understand short-to-medium term options. O-320-E2G for now.

I've found factory replacements for $40k-75k which make even the cheap planes prohibitively expensive. Penn Yan quoted $37k for an overhaul.

One of the engines is at 1500 SMOH in 1981, and ran about 20 hours most years. It had new chrome cylinders in 2009, 180 hours ago, and compressions are all >75. How likely is it that these can be used, and if they can, is it possible to replace only a cam before the crank journals get scored? What other options are there?

 

[Jim K]

One of the engines is at 1500 SMOH in 1981, and ran about 20 hours most years. It had new chrome cylinders in 2009, 180 hours ago, and compressions are all >75. How likely is it that these can be used

Very

, is it possible to replace only a cam before the crank journals get scored? What other options are there?

The engine has to come completely apart to replace the cam. With all newish, good cylinders, I'd consider an IRAN- inspect and repair as necessary. They'll blow the engine apart, inspect & measure everything, replace anything that's out of spec, and put it back together with new bearings and bolts at a minimum. I had my io-540 done after an oil loss incident, and it was 10k with no other parts replaced, although that was 2 years ago now. A new cam & lifters will be a couple thousand. Figure 10k for R&R no matter which route you go.

The downside to an IRAN is it doesn't reset the SMOH clock, and adds little to no value to the engine/plane, so maybe not the best route unless you're going to keep it for a while.

If the plane was stored inside and flown every couple months, there's a chance the engine still has some life in it. They got a look at the cam when they put the cylinders on, so presumably it was good at that time. You won't really know until you get past a couple oil changes though.

Welcome to POA!

 

[Steamflyer]

While a high time engine may soldier on for some time, and there are many data points in the affirmative, one should always assume that any engine might need replacing at any time. Somewhat more likely when there have been years of very few hours of use, but there are never any guarantees.

My last data point with a mid-time engine and too little use (5-20 hours/year for a decade) was 95 hours before the engine ate the cam and lifters. Was R&R’d.

After almost 40 tears of flying, I’d put my money on a more often flown engine over a lower time rarely flown one any day. They rust out before they wear out.

 

[frfly172]

Airplane motors need to fly,fly the motor on condition,expecting that an overhaul could be needed sooner than later.

 

[Richard Frank]

My O540 was just overhauled last summer (50K and 6 months when it was all said and done). I bought it two years ago with about 1000 hours on it since overhaul in 96'. It made it 230 hours before one of the exhaust lifters and tappit disintegrated and fell inside the case. Luckily it all happened on the ground. I had it overhauled as opposed to IRAN because I'll most likely keep it for a good long while. That said, if you like the planes for other reasons, don't let the engine stop you. Fly it as you plan to but be ready to sink that money in it when it happens. Who knows. It may well go beyond TBO. Good luck!

 

[hindsight2020]

I'm looking to purchase my first plane, and I think I have found three that check all the boxes. However, all three of them have had low use over periods of their lives. This has been a consistent theme as I've been looking over the past three months. So I am trying to understand short-to-medium term options. O-320-E2G for now.

I've found factory replacements for $40k-75k which make even the cheap planes prohibitively expensive. Penn Yan quoted $37k for an overhaul.

One of the engines is at 1500 SMOH in 1981, and ran about 20 hours most years. It had new chrome cylinders in 2009, 180 hours ago, and compressions are all >75. How likely is it that these can be used, and if they can, is it possible to replace only a cam before the crank journals get scored? What other options are there?

My personal philosophy has been to stay away from low[frequency] use engines. Ditto for long sits. It's doable, but it's a pretty low % play imo. That said, after 3 airplanes, fate finally caught up to me in spite of my approach/philosophy to the engine question. Airplane #1 (O-200, yes, this man has in fact owned a conti )was too short a stint to count, but technically it didn't set me back any. Airplane #2 (O-320-Dxx) was still going at 2200smoh when I sold it, but I flew like 230 hours in one year, so that thing was basically being flown like a flight school aircraft, which probably helped the high longevity. I'm sure that airplane eventually would have needed one, but I know back then (2012), overhaul prices (yes, inflation adjusted even) were not this ridiculous. They still largely penciled in, even for low hull value. Cheapest flying per capita I've done to date, no question.

Fast forward to airplane #3 (IO-360-C1C), the one that partially came from together inflight. Thrubolts (#3 jug) failed in flight (sept 2023) and I was compelled to sell due to the lopsided economics of hull value and [2023/4] engine repair costs. In my case indexed against an overhaul, not because it was a given it needed one, but because vendors were largely hostile/non-responsive to IRAN. Name brand shops are still too busy for small fry post covid, so they upgauge in order to prioritize high margin customers. Don't @ me about it, I'm out of the certified game now/no dog in that fight anymore.

The quotes I got locally for the RR portion of the engine work were also closer to 40 hours of labor, plus 600 bucks in odd end supplies, so about 6K just for the unbolt/bolt jobs.

My point to you is that this is going to be a creeping reality for those who choose to dabble in the low end of the airplane price spectrum; the economics of inflation adjusted engine repair going forward largely do not pencil out for non-revenue down here, unless you're 200% sure it's going to be a forever airplane. I'm not being hyperbolic when I say I could turn around right now and buy an entire replacement airplane for less money than I would have been out putting the new engine on the old airframe and eventually selling at a loss anyways. Basically, you're buying engines anymore, the airframes are salvage. Imagine now putting 20K of avionics on a zero value airframe. Just something to think about. For me the answer was EJECTION HANDLE-PULL, but everybody will have their own calculus. Good luck to ya.

 

[Kesk]

As far as time 1500 SMOH is fine.

However a quick DRS search shows quite a number of O-320-E2G ADs since '81. Get the serial and run a check as that is likely going to be your limiting factor. Been a while since I've touched O-320s so I couldn't tell you how widespread the ADs are as far as serial numbers. You may simply need to overhaul it anyway. Check the last annual done and see what all was done and maybe check them yourself.

 

[Pinecone]

I had it overhauled as opposed to IRAN because I'll most likely keep it for a good long while.

That is sort of backwards. If you are going to keep the plane, IRAN is fine. Everything is done that needs to be done, but only those things. Overhaul if you are going to sell for value of the SMOH number.

 

[Pinecone]

The issue with overhauling is down time. Talk to the good shops about the lead time before they can even touch your engine. Lately there have been reports of 6 - 12 months for an overhaul.

In that case, consider a Factory Reman or New engine. If you are not down, you can order the engine, and when it comes in, be down a week for the swap, and back flying.

Downside is a LOT more money.

 

[MRC01]

I concur with the opinions that an engine with high hours yet regularly flown is probably in better condition than a low-time engine that sat around. These engines weren't intended to sit around unused and when that happens the tend to rust out. Note that the Lycoming O-320 and O-360 have the cam on top, which exposes it to corrosion after it sits long enough for the oil to drip off. Yet it's very difficult to get a look at the cam lobe & lifters without pulling a jug. And you don't want to pull a jug without a specific reason.
If the engine otherwise checks out good (oil filter, UOA, compressions, borescope, etc.), then fly it. Absent specific evidence that the cam & lifters are corroded or spalled, hypothetical concerns about the possible condition of the cam & lifters wouldn't stop me from flying an airplane with an engine that is in all other ways healthy.
Like many other things, you pay your money and you take your chances.

 

[TCABM]

Every engine is a crap shoot; the longer is sits and the less it runs, the odds turn to Russian roulette. My old advice used to be when you buy, have enough cash reserve for the deferred maintenance you will find during the first annual and enough to cover an overhaul.

Now my advice is just don’t buy a plane as your first plane if it isn’t flying 100/hrs per year since last OH, make sure the last OH was done in the last 12 years, and plan to have the same amount in cash reserves as you bought the plane for, because you’re likely going to burn thru it the first year as a new owner.

For our O-320 that we’re currently exchanging in engine on, price is just under $40K + about 40hrs to R&R. We got almost 2000hrs and exactly 12 years on our motor.

 

[masloki]

Just adding some color to the conversation. Where it sat matters as much as how long it sat. Covid parked 1000s of planes in Nevada and Arizona and they are all flying again.

Rumor has it 80s era motors have better metallurgy than 90s and later era as the economy went more global and quality suffered.

And yeah, if you’ve got the money, buy a runout and the parts, then start the bench overhaul as parts come in at the price you like. And when your flying motor eats a cam, that is the day to bolt your bench overhaul together to set the calendar date.

 

[Ed Haywood]

My long term ownership view: buy the best airframe value you can find. Assume the engine will last NTE 200 hours and budget accordingly. Fly it til it makes metal. Get it overhauled by a good shop, then enjoy two decades of reliable flying.

When you overhaul, budget to replace or overhaul all the other goodies: hoses, oil cooler, mount shocks, fuel pump, prop governor, baffles, etc. And install an engine monitor.