D

David Johnson

Well Known Member
All,

I have the chance to get my hands on a Lycoming O-360-A4M from a Cessna 172 with about 4700 hours SMOH. I know both the engine and the aircraft well, and the I/A who maintains the ship is one of the best in the business, IMHO. Logs are complete and no prop strikes, damage, ADs, etc. Mags, carb, ring gear, are all included.

The asking price is $9000 as is (basically the core charge), and it's running fine with good compressions all around. Assuming that I will perform a complete, proper overhaul with new cylinders and send the rotating parts + case out for inspection and repair, I submit the following questions to all of you:

Question #1: Will this engine work with Van's firewall forward kit (it's a dynafocal mount)

Question #2: Is this a reasonable price in your experienced opinions?

The engine is clean, dry country with no corrosion visible. It literally just came off the rental line this week because "it was time", despite all parameters being normal.

Thanks in advance for your thoughts.

Dave
 
Bit high?

Sounds a bit high... my 1850 TT O-320-E2G core went for $3000 with no access., but with a carb.

The O-360s are more in demand, but I think this is like the -A4K in my Tiger with a solid crank, so a CS prop option will have to be an MT electric one...

Just my thoughts....

gil in Tucson
 
Why would you want to do a "complete and proper overhaul" on a perfectly good running engine that meets good compression and oil consumption parameters? If the engine has 2000 hrs since OH, it should run at least another 5-600 hrs. My engine had 2815 hrs when I overhauled it and all parts met serviceable limits. The only reason I rebuilt it then was to increase power. If it's running well, fly it. Don't introduce unknowns. There are more catastrophic failures after OH than on high time engines.
 
David Johnson said:
All,

I have the chance to get my hands on a Lycoming O-360-A4M from a Cessna 172 with about 4700 hours SMOH. I know both the engine and the aircraft well, and the I/A who maintains the ship is one of the best in the business, IMHO. Logs are complete and no prop strikes, damage, ADs, etc. Mags, carb, ring gear, are all included.

The asking price is $9000 as is (basically the core charge), and it's running fine with good compressions all around. Assuming that I will perform a complete, proper overhaul with new cylinders and send the rotating parts + case out for inspection and repair, I submit the following questions to all of you:

Question #1: Will this engine work with Van's firewall forward kit (it's a dynafocal mount)

Question #2: Is this a reasonable price in your experienced opinions?

The engine is clean, dry country with no corrosion visible. It literally just came off the rental line this week because "it was time", despite all parameters being normal.

Thanks in advance for your thoughts.

Dave
Click to expand...

I had the A4M in the Cozy and loved it. But as Gil points out, it has a solid crank. IMHO, the Lycoming solid crank is all but bullet proof as I've never heard of one failing. There is no front seal AD as there is no seal, and they have no counter weights. The A4M was also the engine of choice in many Cherokee 180's.

I paid $6500 with 1960 hours TTSN, but that was some years ago. The owner opted for a new engine at TBO and the FBO opted to buy it rather than send a perfectly good engine back to the factory. I got it because I knew the FBO. You don't run into deal like that very often.

I assume it has 4700 TT, and if it is coming off a rental line so it probably has hit the 2000 TBO. I think commercial operations require OH at TBO. The only thing I would wonder about it is how many times the engine has been overhauled. Crank shafts are recycled until they no longer meet service limits and then must be replaced. But cranks will go through 3 or 4 OH's for sure. When I had the engine overhauled, the crank was still in new limits, so they last quite some time.

Nine grand is a little steep, but if it is a good tight engine it might be worth it. They ask $6500 for total junk engines these days.
 
A4M

I purchased an A4M with 1988 hours since factory reman. I installed, and ran the engine without issue for an additional 90 hours. I tore it down, sent out case and steel parts for inspection/overhaul, and I'm ready to reassemble. I have spared no expense on this overhaul: balanced crank-rods-pistons, machined-line bored case, new piston & cylinders, cam-lifters. Given the cost of this overhaul, and the fact I paid $8000 for the engine I would not go this route again. I would purchase a brand new ECI engine kit and assemble.
Also if the engine comes out of a C-172 chances are it does not have the fuel pump plunger or the cam type idler gear to run it. This will add $500 dollars to the cost of installation.
LOGAN
RV-4
N21471

P.S. TO back up what Mel wrote: Upon teardown this engine looked good enough ( bearings and all ) to bolt back together and run. I wanted a new tolerence engine and thats what I'll end up with. As I said, looking back I think the ECI route would be the less exspensive, and the route I would take.
 
Last edited:
A4M

I have a 0-360 A4M. It had 2001 hours on it when I bought it. It was out of a goverment plane. I paid 5500 for it, carb mags included. I have installed it in my RV-6 and now have 2150 hours on it. I would like to get another 150 hours before overhaul. The compression are 76 across the board. It uses about 1 quart of oil every 8-10 hours. I only put 6 quarts of oil in at a oil change. I purchased a use fuel pump gear and installed it my self. Cost of $100 dollars. If I was starting over again I beleive I would do the same thing but the supply depot the handle the motors is out of business now. I think I really got a great bargin. I believe now I would go with one of the Lyco Clones. just my two cents.

Jim
 
If you pay more than about $6K for it, then when you do decide to overhaul it and if you do it right, you'll probably just be better of buying a new clone Consider:

$6K core
$4K New cyl's
$3K Case Work, machining, cam/crank inspections, re-bush rods, rockers, etc..
$3K worth of probably new accessories
$2K of hardware, seals, bearings, etc..

Now your'e up to almost a new clone price. Of course the above numbers can vary significantly up or down depending on things like the condition of the cam, crank, case, lifters/plungers, rockers, oil pump, etc...

In the end $9K is just too much IMHO. I just went through re-building another 360 for our RV7 project last fall, and if I would have paid more than $5K for my core (which luckily I didn't), I would have had more into it than a new clone/kit engine.

Just my 2 cents as usual!

Cheers,
Stein.
 
Mel said:
Why would you want to do a "complete and proper overhaul" on a perfectly good running engine that meets good compression and oil consumption parameters? If the engine has 2000 hrs since OH, it should run at least another 5-600 hrs. My engine had 2815 hrs when I overhauled it and all parts met serviceable limits. The only reason I rebuilt it then was to increase power. If it's running well, fly it. Don't introduce unknowns. There are more catastrophic failures after OH than on high time engines.
Click to expand...
Thanks Mel. I realize that there is no magic number for TBO and it all depends on condition. However, at 4700 SMOH without so much as a jug off the engine, I really wonder how far I would try to push it. 5000? 5700? I would start to think about what the plaintiff's attorney would say in his opening arguments: "The defendant's plane crashed after an engine failure. After all, with 6000 hours on an engine that the government requires airlines to overhaul at 2000 hours, one has to wonder about Mr. Johnson's judgement". :D

I definitely agree with you on the unknowns, however. The statistics definitely show that the highest incidence of failure occurs in the first few hundred hours.

Thanks Again!
Dave
 
I paid $6500 with 1960 hours TTSN, but that was some years ago. The owner opted for a new engine at TBO and the FBO opted to buy it rather than send a perfectly good engine back to the factory. I got it because I knew the FBO. You don't run into deal like that very often.
Click to expand...
Thanks David. The $9000 is the core deposit that the owner of the 172 paid to Mattituck when he ordered his new engine, which is where the price comes from. It may be possible for me to get his core charge back for him from Mattituck and negotiate with them for a lower price, but I don't know what the chances of success might be. Thoughts on that anyone?

Thanks for all of the thoughtful, helpful responses so far. I am very glad I asked this question here.

Dave
 
Given the cost of this overhaul, and the fact I paid $8000 for the engine I would not go this route again. I would purchase a brand new ECI engine kit and assemble.
Also if the engine comes out of a C-172 chances are it does not have the fuel pump plunger or the cam type idler gear to run it. This will add $500 dollars to the cost of installation.
Click to expand...
Thanks Logan. Good advice. It does not have the fuel pump idler gear on it. I would have to add that as part of the overhaul, so good catch.

Part of the lure of this engine is the chance to overhaul it myself with the help of an A&P to gain the knowledge of the process. I want to know this engine inside and out. Of course, I could go to Superior's build school with a new one. Based on the comments here, I doesn't seem wise to shell out 9 grand for the engine, however. Point taken, and thank you.

Dave
 
David Johnson said:
Thanks Mel. I realize that there is no magic number for TBO and it all depends on condition. However, at 4700 SMOH without so much as a jug off the engine, I really wonder how far I would try to push it. 5000? 5700? I would start to think about what the plaintiff's attorney would say in his opening arguments: "The defendant's plane crashed after an engine failure. After all, with 6000 hours on an engine that the government requires airlines to overhaul at 2000 hours, one has to wonder about Mr. Johnson's judgement". :D

I definitely agree with you on the unknowns, however. The statistics definitely show that the highest incidence of failure occurs in the first few hundred hours.

Thanks Again!
Dave
Click to expand...
Sorry Dave,
I miss-read. I thought the 4700 hrs. was total time, not SMOH.
 
Mel said:
Sorry Dave,
I miss-read. I thought the 4700 hrs. was total time, not SMOH.
Click to expand...
Not at all, Mel. Your input is always appreciated. I figured you prolly took the SMOH for TT. In fact the number is indeed the total time on the engine since new, as well. This one was built right, apparently!
 
You must log in or register to reply here.