We have a Lycoming O-360-A4M engine on overhaul that needs to have the crankshaft replaced. The shop has given us two quotations — one for a Lycoming crankshaft and one for a PMA crankshaft. The price difference is not negligible (10-15% of the overhaul cost). According to Lycoming SI 1009BB, using only genuine Lycoming parts in an overhaul gives a TBO extension of 200 hrs, making the TBO 2200 hrs. The aircraft is partly used in operations where the engine is TBO-limited so this matters somewhat.
Are there any technical reasons for not choosing the PMA crankshaft? In particular, is there a greater likelihood of problems with the crankshaft at the next overhaul? (The overhaul is done by a reputable shop, so I don’t think they are trying to sell us subgrade parts.)
Who is the PMA crank made by?
Peter wrote:
Who is the PMA crank made by?
Superior Air Parts
Airborne_Again wrote:
Are there any technical reasons for not choosing the PMA crankshaft?
In particular, is there a greater likelihood of problems with the crankshaft at the next overhaul?
I M H O, no & no.
Superior parts saved me from the last Lyco AD. They appear to have fewer problems than genuine Lyco parts.
Indeed, PMA’d parts may even be " Superior" to OEM ! 
Thanks for the comments so far!
Michael wrote:
Superior Air PartsNo, it is manufactured by Engine Components International (ECi), which is owned by Continental Motors Group since 2015. I’m trying to find out if they are manufacturing it under Continentals PMA or if they have their own.
Does anyone know the reputation of ECi?
Airborne_Again wrote:
I’m trying to find out if they are manufacturing it under Continentals PMA or if they have their own.
It is manufactured under Continental’s approval (p/n AEL36001-1).
Continental’s reputation is as good as Lycoming’s I guess and it shouldn’t matter if the actual manufacture is done by a subsidiary. Or should it…?
Superior and ECi were both long term independent companies, competing with each other and the OEMs, with their own FAA PMAs.
Superior is now Chinese owned. ECi was meanwhile purchased by Continental to limit competition for their own engine parts, while maintaining competition for Lycoming parts. Obviously an acquisition through which the Lycoming owner is better off.
I’d run the numbers to see what comes out least expensive over the period of interest and go in that direction. I’m not aware of any quality issues with ECi crankshafts and the origin of the PMA paperwork would not be a great concern to me.
Airborne_Again wrote:
No, it is manufactured by Engine Components International (ECi)
Go back and look at the link that I posted with Superior’s PMA listing , including the before-mentiond crank.
[ post edited to remove rude phrase ]
[ post re-edited to appear to be gentle & kind despite it being entirely wrong ]
Dear Airborne_Again may I suggest that you kindly take the time to read my post with the link to the PMA before making erroneous statements about my posts. .
Have a Nice Day !
