066 Cranks.

[L34]

Hi all at AS,
Will a second gen flat top 066 crank (poly wheel,large taper) fit in an early 066 (ally wheel,small taper )case?
Or are they different widths?and no seal to match the large taper/small seal pocket?
These are both small case saws but the ally case one has busted av mounts.
A quick look tells me the poly crank is overall wider,but could be wrong as I usually am.
@jacobj
Thanks in advance,Chris.

 

[L34]

The ally case crank has some rust on it,that's why I was going to use the other crank.
If there is no rust on the rod bearings and I clean the rest up should be ok to use???
Cheers,Chris.

 

[blsnelling]

No. Different flywheel side bearing.

 

[L34]

Ok,thanks for that Brad.

 

[Jacob J.]

All of the poly flywheel cranks are just slightly wider than the metal flywheel cranks. You can do the conversion if you want
to do some serious machine work but in the end, it's easier to just find the right crank.

 

[BuckthornBonnie]

Different seal area, same bearing... right?

 

[L34]

So the poly flat top is series 2? or 3 of the flat tops.
Cheers,Chris.
BTW thoughts on crank rust,looks only surface from sitting around with no cylinder fitted.
Haven't looked at bearing.

 

[BuckthornBonnie]

The one crank I tried with visible rust failed. It was a 290 and the needle bearing seemed fine.

 

[L34]

Some pics.
Hard to see rollers but no rust on roller cage.
Buck,was it the bearing that failed?
What about bead,shell blasting with the bearing protected?

 

[BuckthornBonnie]

Bearing failed, yep. Saved the p/c since my brother turned it off quickly.

I’ve used a ton of well-used crankshafts before and this was the first failure.

I probably wouldn’t use the one you posted, man.

 

[Jacob J.]

That one is pretty rusty. You might try soaking it for a couple days in a 50/50 mixture of Acetone and Diesel. Another member here turned me on to that trick for rusty chains
and it works pretty well. If the rod bearing is good and tight then it's probably serviceable.

 

[L34]

Thanks gents for the replies.

 

[L34]

Is the early 066 poly crank the same as a late 066/660 crank?
I may have a 660 crank here somewhere.
Cheers,Chris.

 

[blsnelling]

Is the early 066 poly crank the same as a late 066/660 crank?
I may have a 660 crank here somewhere.
Cheers,Chris.

Yes. A poly crank is a poly crank.

 

[L34]

Thank you Brad,and all the others that replied.