[Fot] Odd wear

[J.C. Hassall]

On 11/6/2010 1:52 PM, Mark Eginton wrote:
> I had a headbolt on a new motor that would not pull past 70 lbs but 
> chose to drive it for the summer. Turns out a repaired thread insert 
> from PO of the block cracked the block. So now its winter, I stripped 
> the block today and found some odd wear on the rod bearings I have 
> never seen before. These parts have about 300 easy country miles on them.
>
Mark, I had exactly the same problem with my first engine build; almost 
every tappet had the butterfly pattern.  I don't remember the tappet to 
bore clearance, but ISTR it was high but still w/i spec.  I called Ron 
Isky (I had an Isky 777 grind) and discussed it with him. I returned the 
cam to him and he added an RCH more slope (side to side) to the lobes.  
I also sent all the tappets to Rocker Arm Specialists who tested them 
for hardness and reground them.  The combination of the above worked 
fine.  I read somewhere (one of Kas' books?) to put a dab of white paint 
on each of the pushrods to check for rotation.  Great trick.

hth

jim

-- 
Jim Hassall
Blacksburg VA
'63 TR4 in autox preparation
99% finished, 90% to go