Evaluating an engine core -- O-540

[nichzimmerman]

I know there are some engine experts around here, so let me throw this out there for commentary.

There is an O-540A1D5 engine for sale that I can get delivered to my door for about $6000. It is being sold by a startup salvage company who took this engine out of a Commanche that had sat on a ramp on the coast of Florida for a couple years. Apparently the Commanche was in nice shape and had a brand new 3-blade prop on it but the county auctioned it off because the taxes weren't paid and the registration had expired. As such, there are no logbooks and no verbal records prior to the acquisition by the salvage company. I've made an extensive attempt to contact the previous owner but to no avail. I'm sure there is a mechanic at the local FBO that can do an inspection for me if desired.

Would you buy it as a core?

Thanks,
Nic

[whee]

I'm not an expert and shouldn't even reply but hey...this is the Internet.

I wouldn't buy it for two reasons. 1) If I'm reading the model number correctly it is a dual mag engine. Duals mags are obsolete and only going to get more difficult to maintain. If you are going with electronic ignition this is no factor. 2) Sitting in a highly corrosive environment means that engine is probly full of corrosion. Add the cost of a new cam and other corrosion damaged parts and your good deal isn't so good anymore.

Bob told me $8k is a average price for a good 540 core.

[nichzimmerman]

Thanks Whee, for my own education, what gives you the hint of a dual mag? The TCDS seems to indicate that Bendix -20/21 mags are used. But I know next to nothing about these things yet.

I hear you on the corrosion. I asked if they would guarantee the crank and case but got no response. That's why I would hire a local A&P to pull a jug and look inside before purchasing.

[Battson]

I like Whee's opening comment, I have less qualifications to comment than he does!

A fellow here is running an engine similar to that (regular mags though) off a twin Commanche in his Bearhawk. It was living by the sea and not doing much work before he bought it.
He paid more or less the same money you are looking at.

They stripped it down, cleaned it up, replaced the cam, and had the cylinders re-bored or something - maybe new cylinders - plus a whole lot of extra work. Still, his cost a whole lot less to get flying than mine. Mine is an R&B Aircraft -540 built on a re manufactured case.
Hard to say which will last longer, obviously I am hoping my bigger investment will pay off. His engine has been running fine for about 35hrs so far, but oil consumption is still high (0.5 L/hr ~= 0.45 qt/hr). Mine uses that amount of oil over about 6-10 hours for comparison.

[JimParker256]

I'm no expert, either, but I DO own a Dual Mag Lycoming IO-540...

According to the Lycoming O-540 operator's manual (http://www.squadron302.org/Lycoming_...ors_Manual.pdf, page 1-2), a "D" in the 4th or 5th position of the suffix would indicate it's a Dual Mag engine. This one appears to be in the 3rd position, so likely NOT a Dual Mag engine. The problem with the Dual Mag is that they use a single drive point, and there are no electronic ignitions that can be fitted to that, as far as I know. (My Rockwell Commander 114 uses the Dual Mag, and it's considered to be a "single point of failure" because if the drive itself fails, both mags fail along with it.) But this one does NOT appear to be a Dual Mag engine, so that's not the issue.

However, I personally would have very little interest in an engine that had sat outside on the Florida coast for a couple of years. Add to that the fact that it takes a while to go through the process of obtaining the rights to sell an aircraft for the taxes... That couple of years could translate to anything from 2 to 20 years... And you don't know how long it sat outside before the owner gave up and stopped paying the taxes... After in that salt air for more than a year without being operated, the odds are that the cam and crankshaft are corroded. I would only be interested in it if I could purchase it for the price of the case alone, so that anything you find usable is a bonus to you. If you DO elect to pursue it, follow through on your plan to have an A&P pull at least one (and better two) cylinders to examine the insides of that beast... This is pretty much a crap-shoot, and you could even wind up with an unusable case if there are any hidden cracks that cannot be repaired, etc.

Personally, I would run, not walk, away from this deal. Good luck!

[Battson]

Quote: According to the Lycoming O-540 operator's manual (http://www.squadron302.org/Lycoming_...ors_Manual.pdf, page 1-2), a "D" in the 4th or 5th position of the suffix would indicate it's a Dual Mag engine. This one appears to be in the 3rd position, so likely NOT a Dual Mag engine.

This ^ was also my memory, but I didn't have time to check. I recall that have an IO-540-A4D1 (or was it 5?) which means normal bendix mags.

[whee]

Glad you guys are around to correct me. I remembering that the "D" had to be in the second to last position. Sorry for the screw up.

[whee]

The "D" in the model number designates dual mag. You'll want to verify that to be sure though. I almost bought a O540 off a Maule that had dual mags. I asked Bob about it and he said he wouldn't touch it. I hadn't yet told him that the cam was spalling from infrequent use. It had good compression and was at 1800SMOH so I was hoping to just put a cam in it and get another few hundred hours out of it. After talking to Bob and him telling me $8K for a good core I decided to pass on the engine. The seller wanted $8K.

[patrickh99]

• O-540-A1A: 8.50 compression, basic engine.
• O-540-A1A5: Same as O-540-A1A except different counterweights.
• O-540-A1B5: Same as O-540-A1A5 except short prop governor studs andtwo impulse magnetos.
• O-540-A1D5: Same as O-540-A1B5 except retard breaker magnetos.

[patrickh99]

I would be nervous about an engine that has sat in the salt air for that long.

[marcusofcotton]

Retard breaker magnetos.

This copy and paste is from Lycoming:

O-540-A1A 250/235 2575/2400 100/100LL 8.50:1 Two sixth order counterweights -40
O-540-A1A5 250/235 2575/2400 100/100LL 8.50:1 Same as –A1A but (1) fifth and (1) sixth
order counterweights
-40
O-540-A1B5 250/235 2575/2400 100/100LL 8.50:1 Same as –A1A5 except for short prop.
governor studs and two impulse coupling
Magnetos
-40
O-540-A1C5 250/235 2575/2400 100/100LL 8.50:1 Same as –A1A5 except for two impulse
coupling Magnetos
-40
O-540-A1D 250/235 2575/2400 100/100LL 8.50:1 Same as –A1B5 except for two sixth order
counterweights with Retard Breaker
Magnetos
-40
O-540-A1D5 250/235 2575/2400 100/100LL 8.50:1 Same as –A1B5 except for Retard Breaker
Magnetos
-40

I'd run from the likely severe corrosion.

Edit: I see Patrick beat me to the details.

[marcusofcotton]

I'm no expert, either, but I DO own a Dual Mag Lycoming IO-540...

According to the Lycoming O-540 operator's manual (http://www.squadron302.org/Lycoming_...ors_Manual.pdf, page 1-2), a "D" in the 4th or 5th position of the suffix would indicate it's a Dual Mag engine. This one appears to be in the 3rd position, so likely NOT a Dual Mag engine. The problem with the Dual Mag is that they use a single drive point, and there are no electronic ignitions that can be fitted to that, as far as I know...

Jim,
Check out Electroair and Lightspeed ignitions.

[JimParker256]

I should have clarified that I was looking at certified systems for a certified airplane. There may be something for experimental aircraft, but the market for the dual-mag replacements is pretty small.

I spent a couple of hours with the Electroair guy at a Commander Owners Group meeting a year or so ago. They are working on one, but FAA approval is proving very difficult. Lightspeed says they aren't even working on it.

[nichzimmerman]

This just in...They are apparently willing to guarantee the crank and case. If this comes to fruition, and at the end of the day all I have is a serviceable crank and case, it seems like it was still worth the investment. I will still ask a mechanic to have a look. Thank you all for your input. Any additional thoughts?

[whee]

Make sure the crankshaft isn't one that was condemned by the Lycoming crank AD from several years back.

[alaskabearhawk]

I bought an IO-540 C4B5 out of an Aztec in St. Louis, no logs...long story. Anyway, I paid $8000 for the core with the guarantee the case and crank were good and nothing else. I had the engine sent to Aircraft Specialty Services in Tulsa and they did a complete teardown and Divco did the case. If either one failed I would get my money back 100% and it went through escrow too. There were many good pieces on the engine, but a lot including the cylinders and mags were junk. Bottom line: Get it in writing, have a QUALIFIED professional engine shop do the inspection work, put the money in escrow and don't hand over a dime until you have two good yellow-tagged items. If it's legit...it's legit.

[JimParker256]

Excellent advice!

[Battson]

This just in...They are apparently willing to guarantee the crank and case. If this comes to fruition, and at the end of the day all I have is a serviceable crank and case, it seems like it was still worth the investment. I will still ask a mechanic to have a look. Thank you all for your input. Any additional thoughts?

Sounds like you might have a deal, if you approach it carefully.

Personally, I would be putting new cylinders on it and replacing the cam anyway - esp. if you are splitting the case as a given. You can always recover at least some cost by selling junk parts at core value - such as mags.

[Gavin Chester]

The Bendix D3000 dual mag is actually a very good mag with few AD's , most of the Problems are from poor installation and poor assembly. Hartzel technologies rebuilds them and has all new parts for them. There are many single points of failure in a single engine airplane. One added bonus to the dual mag with impulse coupling is that it fires all plugs on start. If you do not want the dual mag it would be very easy to make an adapter for a single mag and then you can drill the flywheel for a pickup magnet and run a light speed type electronic mag . Or run two electronic.