Did he check end-play (that is, has he had the flywheel off)? I have an
engine on the floor of my garage that ran fine until I pulled off the
flywheel and added shims to adjust end-play (okay, so compression was down
to 75# on one cylinder and it used about 1/4 quart oil per mile, but other
than that it ran fine). Turns out the crankshaft had done some interesting
stuff to the bearings (wore them out and possibly reshaped the front of
the case for me) and when I added shims it managed to bind up and wouldn't
turn. 

Can't think of any other reasons, though I'm sure there are many.

Joe

On Mon, 25 Mar 1996, Morris H. Arthur wrote:

> My friend has a '73 motor on which he's doing a quick rebuild. (new rings 
> only). After putting the heads back on, he has determined that the engine 
> will turn counter-clockwise, but not clockwise. What could be wrong?
> 
> +++ Morris Arthur < morris_arthur@unc.edu > +++
> +++ Environmental Sciences and Engineering  +++
> +++ University of North Carolina            +++
> 
> 

----------------------------------------------------------
Joseph F. Fournier II <jfourni@comp.uark.edu> 501.575.7353
<a href="http://comp.uark.edu/~jfourni/"> Joe Fournier</a>
----------------------------------------------------------