I just noticed this thread a bit late, but
I have to second what others said: Just helicoil it.
My block had one hole partly stripped for years, and
a few months ago I noticed more oil than usual
on my garage floor. I found that one of the front
oil pan bolts had simply fallen out of the its hole.
So I bit the bullet, took off the oil pan, and
bought a heli-coil kit.
It is easy to helicoil that block, especially because
it is aluminum. I have a cheapo small drill press,
so I could drill out the holes squarely. Here is
another trick: Take off the belt of the drill press,
put the tap in the chuck, and turn the drill press
spindle pulley by hand to tap the hole squarely.
Places like Pep Boys sell some rethreading kits pretty
cheaply, but not for fine threads. The best deal I
found for the correct thread size was from
McMaster-Carr.
If you already have the engine apart and the block
in your hand, you can do this job a lot more easily
and cleanly than I could, so you ought
to invest the $35 that the rethreading kit costs.
Sooner or later you will use it for something else,
since the 5/16-24 thread is used in a lot of places
on a Spit.
BTW, I just re-used the original wood blocks.
After I finished the job, the front of my engine
leaked no oil at all.
Doug Braun
'72 Spit
=== This list supported in part by The Vintage Triumph Register
=== http://www.vtr.org
|