Crankshaft interchangeability

Jim McCartney · Post by **Jim McCartney** » Fri Mar 10, 2006 09:07

I am assembling parts for my engine, finally! Will an A65-8 crank work in a C85-12 engine? I hope to fly my Champ to Arlington after a nine year restoration. Thanx, Jim

Nathan K. Hammond · Post by **Nathan K. Hammond** » Fri Mar 10, 2006 13:34

I believe the A series and C75/85 cranks are all the same dimentionally. You can tell the different in an "A" and "C" by observing hollow journals on the "C" series I believe. Legally can you do it......hmmmm not sure. Check out this publication on interchangalbe parts.

http://www.bowersflybaby.com/tech/Conti ... alogue.doc

nkh

Ron Babos · Post by **Ron Babos** » Fri Mar 10, 2006 15:55

Same crank.
Ron

MikeB · Post by **MikeB** » Fri Mar 10, 2006 16:36

Nathan,
Thanks for posting the Continental manual site. That's really good information. I made a CD copy of it for future reference.

If I read the parts manual correctly, it appears that the cranks are the same for A series on up to C-90. Guess I always thought the 85 and 90's were different, but I've never had a 85 apart either. I have two tapered cranks in my shop that came out of A65's with a casting numbers of A5334 on both. One is solid through the journal (drilled internally) and the other is open through the journal with external oil tubes (through the journal openings).

Good information, anyway

.

Mike Berg

Nathan K. Hammond · Post by **Nathan K. Hammond** » Fri Mar 10, 2006 19:44

About the C90 crank, I read that too. Doesn't make sence though because a C90 and O200 crank are the same, 3 7/8 stroke, while the A65/75 and C75/85 are a shorter stroke. Maybe a misprint???

Anyway the root page is full of GREAT information. Harry Fenton worked for Slick (Mag's) for a long time and knows little engines, so what he say's I'll believe!
www.bowersflybaby.com/tech/fenton
Good stuff!

nkh

Ron Babos · Post by **Ron Babos** » Fri Mar 10, 2006 21:47

Nathan: You are correct, the c90 is not the same crank. For one thing , it came nitrided from the factory, and like you mentioned the stroke is longer.
Ron

MikeB · Post by **MikeB** » Fri Mar 10, 2006 22:37

Guess the beginning of Section Two does explain it and excepts the C-90's. I didn't look hard enough and now I see the stroke on a A65/75/85 is 3 5/8" and a C-90 is 3 7/8" It would be nice to have a C-90.....but...

.

National Aeronca Association Bulletin Board

Crankshaft interchangeability

Crankshaft interchangeability

parts interchange

cranks