Flathead V8 Welch Plugs

Tony Smith · #1 28-12-08, 15:53

Until a Moderator takes Bob's "Hint, hint" and links This thread to this current one, may I suggest using threaded Allen Plugs? 3/4"UNC ought to do the job fine (Or should that be Coarse?).

Also, I don't think these can be regarded as "Frost plugs" as once the sump pan is secured in place, these plugs would have nowhere to go IF the coolant in the waterjackets did freeze over.

sth65pac · #2 28-12-08, 22:27

Tony,

Questions/clarification

:

Are you saying you need to tap a thread into the hole and then fit a threaded plug? I presume you would have to use some red silicone sealant to provide a gas/watertight seal.

How long is the 3/4 UNC allen plug? 1/4"? Is it a standard length.

I have this task ahead of me in the next few weeks. My engine is 'resting' on the garage floor now.....

Ian

Keith Webb · #3 28-12-08, 23:13

...for all the suggestions and help. I measured 18mm but I think 3/4" would make sense. There is only a small lip in which to nest them which is why the originals are dished rather than cupped. It's interesting just the sump gasket managed to seal this in the past - but there was a lot of gunk built up in there.

Tony, have you tried the allen plugs? I would have thought they were too deep to fit.

Bob Moseley (RIP) · #4 28-12-08, 23:40

Thanks for your comment Tony. I cannot believe the lack of knowledge of such a basic engine componant, although I must admit I haven't heard of or seen an Allen Plug. Welch plugs are readily available but if possible try to obtain the brass ones as most originals were steel. They are simple to fit, merely place them in the hole in the block with the concave surface to the outside and then expand the plug using a hammer and a drift. A touch of gasket cement around the edge of the hole wouldn't go ammis either. In the meantime read my thread on these or get that thread linked.

Bob

Keith Webb · #5 29-12-08, 03:08

OK... I found Automotive Surplus in Mitcham was open and they keep a range of welch in stock. Interestingly they said they had sold some to somebody else recently who had the same situation - two were missing when the sump was removed.

3/4" is the correct size, thanks Tony.

So the sump is now back on... the next job is to attack the water pumps with a press. Has anyone had experience in pressing water pumps apart? I'm thinking a bit of heat on the pulley and impeller might not go astray.

Keith Webb · #6 29-12-08, 11:43

So far managed to break the casting on one pump.

Might wait for someone more expert to have a go at it.

Here's a shot of the new welch plug.

John Stokes · #7 29-12-08, 13:41

Quote:

Originally Posted by Keith Webb

So far managed to break the casting on one pump.

Might wait for someone more expert to have a go at it.

Here's a shot of the new welch plug.

Hi Keith your welch plug looks like it is up side down ? Thanks for the parts i have nearly finished the transfer case ,shift tower and linkages hope it rains tomorrow so i can stay in the shed catch up soon. John Stokes