On Mon, 1 Sep 2014 15:37:22 -0600, "L Fisk" wrote:


"L Fisk" wrote in message
...
Need to weld a broken starter mount tab (outside hole)
on a SBC block. Hole is way beyond using a thread insert
Fairly experienced at arc welding cast with nickel rod
but also have a mig welder.

It looks like this pic
http://www.carcraft.com/techarticles...photo_01.html#

except mine is wallowed out larger till there is not much meat around the
end at all
think I'm best to weld it up solid and drill/tap a new hole
I know about preheating and peening the weld on cast
If there were any threads left I would thread a peice of carbon and weld
around that
I have the block out and stripped bare, so now it the time
might find a new block for around $500
but this one is good except that little problem
thanks for all the quick replies :-)
Last week I needed to repair a transom clamp on a Johnson outboard.
The original 5/8-11 threaded hole was stripped and there wasn't enough
material for even a Heli-Coil insert. So I tapped the hole 3/4-16 but
used a drill much larger, relatively, than the normal minor diameter
of the thread. I then made an insert on the lathe tapped 5/8-11 and
threaded 3/4-16 on the OD. The 3/4-16 thread was really only about 50%
because I made the minor diameter only .003" smaller than the hole I
drilled in the transom clamp. To do this I set the compound on the
lathe parallel with the Z axis. Then after single point threading
until I got to the minor diameter I wanted I used the compound to
advance the treading tool .002" per pass and widened the thread until
the pitch diameter was correct. So the insert ended up with shallow
threads with a really wide root. Finally the insert was installed with
Loctite so that any clearance between the insert and the part was
filled. I made the insert from stainless because it was for an
outboard motor. In your case I would use any easily machinable steel
you have laying around. Ledloy would be plenty strong enough. 303 SS
would be a good choice as well as 17-4 or 15-5 SS. Though the PH
stainless steels are not that easy to machine they do finish nicely. I
would not use mild steel because it tears so easily.
Eric