Jeff Wisnia wrote:
Jhock wrote:

Since this is a metal working group, I have a problem I need help
with. I decided to put a new muffler on my 8 hp B&S aluminum block
engine, the old muffler will absolutely not come out. I have taken
the engine down to the basement as it needed some repainting anyway
and have been soaking the muffler joint with PB Blaster, Tefoil, WD 40
and then tried some heat with the welding torch, enough to get the
muffler stub red hot but didn't want to do any damage to the aluminum
engine part. I have put a pipe wrench on the muffler and pulled,
hammered, etc and it will not budge. Have cut off the main part of
the muffler so there is about 1 1/4 inch stub remaining. May have to
carefully grind slots into it in about 4 places where it threads into
the engine after cutting it off flush, before I go to this extent does
anyone have any experience with this type of metal seizing. Sorry for
the long post.

Jack



Just a WAG, but since aluminum has a much larger coefficient of
expansion than steel, maybe you'd be better off heating the block around
the muffeler stub and trying to chill the steel parts with a shot of CO2
or something like that?

HTH,

Jeff


My technique:

Crank the engine and let it heat up. Then shut it off. Apply a birthday
cake candle to the junction of the muffler and block. Grab the muffler
or stub with pliers or a pipe wrench and spin it out. Works every time.