Jack:
I've had the aluminum plug dissolve also when I gave it to my machine shop
to do a valve job. I ordered a replacement plug from Roadster Factory I
believe, and got a round bar of aluminum that was a series of threaded
plugs. This was designed so you could thread it into the head and then
break it off. I installed this and found that it leaked slightly. I then
coated it with a coat of some type of epoxy and have had no leaks. I did
this about 10 years ok and have had no problems on this street car.
Dave
----- Original Message -----
From: "Jack W. Drews" <vinttr4@geneseo.net>
To: <FOT@autox.team.net>; <triumphs@autox.team.net>
Sent: Friday, August 05, 2005 6:15 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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