Yeah Jack, I too tried to use the stock alloy part to replace the plug and
without at least a coating of epoxy I don't think it is workable. I just
tapped the hole and went home early.
In cutting heads apart (for your same reasons) I have found lots of pieces of
wire and other junk. You may also find that kind of thing in the valley for
the cam followers.
----- Original Message -----
From: Jack W. Drews
To: FOT@autox.team.net ; triumphs@autox.team.net
Sent: Friday, August 05, 2005 4:15 PM
Subject: head plug
In the top of the TR3-4 head is an aluminum plug which partly
dissolves when the head it put into a caustic tank. To replace it, I
have been tapping out the hole and replacing with a pipe thread plug,
which is foolproof, but the tapping sis not pleasant. Recently Moss
made available an aluminum plg with the proper threads to match the
hole. I just used one and it leaks, so thank goodness formy test
stand, where I found this problem. I'm going to tap it out and use a
pipe plug again, but I wondered if anybody else has had experience with
this.
By the way, I recently had a Spitfire head sawed up to determine wall
thicknesses of ports. When I got the pieces back, I was astonished to
see the amount of crud in the water passages, all but blocking water
to several of the critical areas. this supports the notion that
having the castings cleaned in a caustic tank is a really good idea,
despite the inconveniences it causes in plugging up the passages that
were previously plugged with aluminum.
uncle jack
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