Used IO-360 A1B6D. What to look for...

[jtop]

I've found a used A1B6D. It came out of a m20j mooney.

Approx 3600 TT, 1800 SMOH. Logs, no strikes.

What do I need to be looking at specifically before I decide to buy it? Do the logs have anything about the crank tolerances since last rebuild? Its been out of the plane for a few years. It was running when pulled, they just replaced it with a new engine. I'm not sure how well it was pickled.

(I know its a bendix single mag engine but I plan on implementing a crank trigger EI along with a single mag)

[hgerhardt]

I bought one of those very engines for my -6. Except mine is a later model A3B6D. (reclocked prop bushings is the only diff) And I also added dual Lightspeed ignition in place of the D3000 single mag.

In your case, you gotta ask yourself, why did they remove the engine if it only had 1800 hours? You'd be hard-pressed not to think there's something wrong with it. The logbook would generally not show what the crank clearances are. Only that all the clearances meet spec (what spec? who knows).

Heinrich Gerhardt
RV-6, 330 hours

[mikegraycmg]

Could be a good deal, if the price is right. You are taking a chance, though. The crankshaft is the single most expensive item. If that's good, there's still a fairly expensive overhaul that probably needs to be done. Check for ADs on the crank before you buy it. See if you can get a warranty that the crank is serviceable. Then, if you buy it, replace or rework the cylinders, redo the cam, case and lifters, and go for it. It's not likely to be more than a new engine, and, by the time you get it overhauled, you'll have a very nice engine. That's what I did with an A1G6D off a Beech Duchess.

BTW, there is likely to be be nothing in the records about the condition of the crank. If no warranty is available, with the risk you are taking and an impending overhaul, I would pay no more than about $3,500 - $4,000 for the engine, and that's if the crank serial number is not subject to an AD requiring replacement.

[jtop]

Got a copy of the logs. Trying to sort through them since they were scanned. It does say that the engine was torn down for a "sudden stopage inspection" awhile back. Crank was sent in for repair.

As far as I can tell the crank isnt affected by the AD.

It was supposedly pulled out of the airplane since it was within 200 hrs of TBO. Compressions are all in the low 70's in the last inspection.

If I buy this I'm planning on overhauling it anyways. Just wondering if the crank is any good.

[John Clark]

A couple of concerns. You mentioned that you didn't know if or how well the engine was preserved after removal. Rust could be a major issue. The statement about why it was removed is a little strange. If it was running well why was it removed 200 hours "early?" In normal service that is around two years. Hard to believe the owner wanted to spend 30K on a new engine two years sooner than needed. The crankshaft AD is probably not an issue, but I would be concerned about what "removed for repair" means. Bent flange? It would be nice to see some receipts along with the log books.

John Clark ATP, CFI
FAA FAAST Team Member
EAA Flight Advisor
RV8 N18U "Sunshine"
KSBA

[MrNomad]

I went thru same decision twice. On the first O-360, we measured the crank while it was inside the engine & it checked ok. Once it was outside, it was 22 thou out and had to be replaced.

On engine #2, after we opened it & shipped the parts for inspection, the crank had a crack at one of the journals (yellow tagged replacement cost $2500), the case had two cracks (DIVCO rebuilt for $700+ freight), all 4 cylinders were cracked (rebuilt jugs, new rings and serviceable pistons were purchased for $2300), but the cam, lifters & rods were capable of a rebuild. In total, engine #2 cost us approx $7500 and a lot of work. Fortunately, we paid almost nothing for the core which is exactly what it was worth.

Bottom line? Until you open it and send the parts to vendors like Aircraft Specialties and DIVCO, you have no idea what you purchased. Logs will give you some info, but they will not tell you how many times it was shock cooled, run too lean, and subjected to a myriad of other bad habits.

Would I spend $4k on a run out engine? No way.

[AK4x4]

I would be concerned. It is very common on part 91 private aircraft for the engine to wear out well before TBO. This is due in part to the aircraft flying a limited number of hours each year (typically 50 or less) resulting in early failure. For normal engine life the aircraft should be flown 30hrs or more per month or have the engine preserved if inactive for more than 30 days. Remember the TBO on most Lycomings is 2000hrs or 12 years which ever comes first. The IO-360-A series can have 1200, 1400, or 2000hr TBO's depending on dowl pin size and crank shaft p/n. read Lycoming service instruction SI1009AU including the notes. When an engine is removed it is important that Service Letter SL180B is followed to prevent damage during storage. If the engine was not properly "pickled" apon removal it probably has little value now. Best of luck with your project, Russ

[MrNomad]

Russell's comments helped me recall another "great deal" a friend came upon, a Piper with "running" engine for $15k that was sitting outside for more than a year. Yes, the engine ran, and in short order used 2 qts of oil every 2 hours.

Buying a used engine is a **** shoot alike buying a used car. If you know the previous owner, and if he/she was meticulous and knew how to care for the engine, your odds increase that you will get some reasonable service out of it. But anything other than optimal conditions carries great risk and the price should reflect that risk.

When my grandson or wife of 41 years is sitting next to me in the airplane, the last thing I care about is how much money I saved on an engine.

[Noah]

I have an A1B6 - same engine, except your engine has dual magnetos driven off one shaft. I overhauled my engine myself, similar situation to yours. I would pull a jug and inspect the camshaft. These camshafts tend to go early on these engines, due to lack of good lubrication, especially at startup, and cam lobe rust from lack of use.

Specifically, you want to inspect the two cam lobes which drive two lifters, since these see the most abuse. If the cam lobes are worn down more than the others, you have to ask yourself where that metal went. In my case, some of it got into the crank journals, requiring machining and re-nitriding of the crank which is a big deal, and weld repair of the case, which is no big deal. Not the end of the world, but more money in addition to a new camshaft and new lifters. The big question at this point is, is there enough material in the crank to machine it down? Ten thousandths undersize is the most you can go, so its important to determine whether the crank has been machined before or not. You are looking for numbers in the log like M003 (.003" undersize), M006 (.006" undersize), or M10 (.010 undersize). Obviously, if the crank in this engine is M10 (crankpin journals or mains) then you are scrapping the crank if there is any damage to the journals since there is insufficient material to machine it down any more. If the crank is at factory spec or M003, that would be good. My crank went from M003 to M010 when I had it machined because the scores were that deep from the camshaft.

Bottom line, I would try to negotiate for disassembly prior to purchase, or some guarantee that the seller will offer a refund if the case, crank, and camshaft are not able to be yellow-tagged after inspection.

Good luck.

[mannanj]

Originally Posted by Noah

I have an A1B6 - same engine, except your engine has dual magnetos driven off one shaft. I overhauled my engine myself, similar situation to yours. I would pull a jug and inspect the camshaft. These camshafts tend to go early on these engines, due to lack of good lubrication, especially at startup, and cam lobe rust from lack of use.

Specifically, you want to inspect the two cam lobes which drive two lifters, since these see the most abuse. If the cam lobes are worn down more than the others, you have to ask yourself where that metal went. In my case, some of it got into the crank journals, requiring machining and re-nitriding of the crank which is a big deal, and weld repair of the case, which is no big deal. Not the end of the world, but more money in addition to a new camshaft and new lifters. The big question at this point is, is there enough material in the crank to machine it down? Ten thousandths undersize is the most you can go, so its important to determine whether the crank has been machined before or not. You are looking for numbers in the log like M003 (.003" undersize), M006 (.006" undersize), or M10 (.010 undersize). Obviously, if the crank in this engine is M10 (crankpin journals or mains) then you are scrapping the crank if there is any damage to the journals since there is insufficient material to machine it down any more. If the crank is at factory spec or M003, that would be good. My crank went from M003 to M010 when I had it machined because the scores were that deep from the camshaft.

Bottom line, I would try to negotiate for disassembly prior to purchase, or some guarantee that the seller will offer a refund if the case, crank, and camshaft are not able to be yellow-tagged after inspection.

Good luck.

Ditto on most of the above, especially the last paragraph. You have a 99.9 percent chance that you'll have to replace the camshaft and lifters. That's almost guaranteed at 2000 hrs. That will cost about $1200 for parts. Cylinders are $2000 each if you'rs can't be O'hauled. I'm guessing that the Crank inspection after the sudden stoppage cleared most doubts if it was yellow tagged and re-installed in the engine. If the Crank is no good, count on $6000. The crankcase can cost up to $5000.

So---If you can get the engine for less than $5000 with a guarantee that the Crank, Case, and Accessory Case are good, and you can do the work yourself, you should have a good engine for well under new prices when finished.