National Aeronca Association Bulletin Board

I am probably going to need a crank for a c-85. After sitting for quite a spell, the taper part of the shaft is pretty rusty. I just talked to a guy who said that the A series cranks could be used in a c-85. Is this true? I have heard that the A series crank is different than the C series. I have also read something about the hole sizes in the journals being different. I have also heard that the solid journal can be used on either, but I'm not certain. So, can someone tell me what the scoop on these is?

Mike

Mike, I don't have the details, but the C-85 cranks have a smaller hole in the crank journal than the A series. I ran an A series crank in my C-85 for about 5 years by mistake. Ran the snot out of it too. Guess I will go to the Super 85 when I rebuild to get away from the crank availability problem and get more power. David J.

I've got two tapered nose A65 cranks sitting on my shelf. I think the part number on both of them is A-5334. I say "think" because I oiled and wrapped them a couple of years ago. One has 1" holes in the journal area and the other has 1 1/8" holes. The one with the 1 1/8" holes has tubes rather than drilled passages to the rod journals for whatever it's worth. It seems like both can be used in a A65 but only one of the two can be used in the C85s....or so I've been told. They're both standard size but probably need to be reground and I've been hanging on to them for spares to rebuild a A65 engine sometime down the road.

I've got a book someplace that tell what cranks fit where............

My understanding is that there's a shortage of 0200 cranks now as so many have turned up cracked. I need to pull my 0200 down and get it checked, I guess.

MikeB

Looking at my interchangability book, it reads:

A series, C75, C85

53196-A1 (taper) 3 5/8" stroke. These shafts are interchangable on all 4 cylinder engines except the C90.

530199-A1 (flange)-3 5/8" stroke. These shafts are interchangeable on all 4 cylinder eingines except the C-90

It also looks like there might be a difference in some of the C series crankcase assemblies but having never owned one I can't help you out there. Interesting though as the info above says for ALL 4 cylinder engines except the C90.

MikeB

Thanks MikeB.

Mike

Mike

You can get a new O200 crank--the Aircraft Specialities STC comes with a NEW O200 crank and pistons. The shortage now is C85 cam shafts--the problem is not the lobes but the journals that sit in the case--evidently they were not hardend properly.

Doug

Thanks Doug,
Maybe I heard wrong. Hopefully I won't have to worry about it.
Mike

I just saw a crank with the number, A35908 on it. Is this a A-65 or C75/85 crank? This crank is a flanged crank, not taper shaft.

Mike

Mike

According to my info that crank A35908 has a flanged front surface on the front thrust bearing and is used with crankcase assembly 530135-A1. Hope that helps. It is an old style C75/C85 crank.

Doug

Thanks Doug.
I was under the impression that any C75/85 crank could be used in any C75/85 case. Is that not true?

Mike