Another quickie question, i have just found a leak from my welch plug on the back of the engine head.

Thing that pisses me off is that the machine shop put these plugs in when the engine had work done to it so its THEIR fault it happened....i need to blame some one

The water drips when off but as it warms up shoots about a pin hole of steaming water on my firewall, i tried to just seal it with a bit of gasket sealer but just shot thru that.....Maybe i should try with hard setting gasket sealer or what would be a good application for such a dilema? Maybe something like a hard metal like setting epoxy stuff i.e. that quick steel stuff, ive used that and its worked a treat...
I really cant be stuffed taking off the head and fitting a new plug as its going into pro carb on friday for its final tune so it kinda needs to stay on....

Dave

If the welch plug has a pinhole, it is most likely a rust hole in the original welch plug. If this is true, then it obviously wasn't replaced when the head was off last time.
Why any reputable tradesman, or machine shop doesnt replace it with a brass one while the head is off, is beyond me, but this one & the one behind the flywheel should always be replaced with brass,... or stainless if you can get it.

Now for the bad news, although i'm sure that you already know. The only real way to perform a proper repair here is to remove the cylinder head. You could cut a 4" hole in the firewall to access it, but i don't think that you would seriously consider this option.

So a couple of tips here for others.
1. ALWAYS replace the original welch plug whenever the head is off & is to be refitted. No exceptions,... ever.
2. For the few paltry cents extra, always replace it with a brass or stainless one.

As writen above, this would apply to the one behind the flywheel too. If the trans is out for a clutch replacement, then pop the flywheel off & save yourself a whole lot of grief later on.