> wrote in message
oups.com...
> long story short, a small (1/4" 5/16" diameter?) thermostat housing
> bolt broke. about 3/8" of it is sticking out of the aluminum engine
> block, with the cap missing. i want to heat it up, but only have access
> to a cheap propane torch. will this do any good?

Yes, it will. Aluminum expands at a higher rate than steel so even
just heating both parts will cause the bolt to be 'looser' in the
aluminum casting. Note that it is perfectly possible to -melt-
aluminum with a propane torch.

note also that it is quite easy to destroy aluminum threads in
this kind of operation.

> i was thinking that
> heating, then one of the craftsman socket-like removal tools.
>
> thoughts? there isnt any chance of damaging/warping anything with a
> measly propane torch, right?
>

There is a chance of warpage. What I would suggest is you go to an
electronics distributor or computer supplier and buy a can of "freeze spray"
this is sold specifically to find thermal intermittents on circuit boards,
the
can costs about 6 bucks.

Next, heat up the thermostat housing slowly, moving the flame around.
Aluminum conducts heat very well and will wick the heat away from the place
you
heat up, which is what you want. Let the entire manifold get hot, to
around 210 to 220 degrees. Use a thermometer, you can get laser
thermometers now that are pretty cheap. Once everything is nice and
hot, hit the stud with the freeze spray for about 15-30 seconds, try not
to get it on the manifold. Then, quickly before the stud can absorb heat
from the manifold again, use the vice grips to turn the bolt out.

If you can't get it out then the best bet is to use a grinder and flatten
the
top of the bolt, then use a center punch to make a good solid dimple
in the exact center of the bolt. Then use a well-sharpened drill bit to
drill down the center of the bolt, go very slowly, carefully, and absolutely
down the center. Use a large bit that it a slightly smaller diameter than
the
bolt. Then follow this with a heli-coil kit.

Ted