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
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