MTFCA Forum

I pulled the exhaust and intake manifolds off as part of a check and clean up on my T. The front waterjacket plug looks good. It looks like there has been some trouble keeping the center plug in place. The rear one has me a bit concerned as it looks like it has been leaking through a small pinhole. How bad are these plugs to replace? I really don't want to make things worse & seeing how the center one has been welded up has me a little concerned about what I might be getting myself into.

Looks like normal rusted out core plugs. Not sure there has been any welding done??? Order some from one of the parts vendors. Drive a punch into them, pry them out. Use a sharp edged tool to clean out the counterbore in the block. Clean everything well- small rotary wire brush works well.
Coat the bore with #2 Permatex. Place the core plug in with the concave side out in the counterbore in the block. A 9/16 socket is just about the correct diameter to use to seat the new core plug in the block. Once its in place, expand the core plug by hitting the center with a flat round rod or punch. The square end of a ½ extension works ok if you don't have anything else to use.

All 3 off those need to be replaced. I don't think the center one appears to have been welded. I think that's just a but bubble of rust on its face. What is the light brown thing hanging down below it? A stalactite of rust? And please, don't use the buffalo nickle method. Use a proper freeze plug/core plug.

Dan McEachern wrote: ↑

Fri Dec 29, 2023 4:20 pm

Place the core plug in with the concave side out in the counterbore in the block.

Maybe convex side out???

Thank you for the quick responses. I called Lang's and got a set of plugs added to the order I placed this afternoon. I'm not sure what is showing up in the picture, but there isn't anything hanging down from the center one. I think it might be some light coming through the gap between the center cylinders.

Boaski wrote: ↑

Fri Dec 29, 2023 4:55 pm

...there isn't anything hanging down from the center one. I think it might be some light coming through the gap between the center cylinders.

Ha! Makes perfect sense! Thanks.

The brass plugs will last longer than the steel ones and not rust. The convex side is the one which the raised center faces outward.
Norm

I’m in the buffalo (really bison) nickel camp. Do it right with the #2 permatex and it’ll add class and never leak. I have a Folger coffee can full of ‘em. Use 1 stamp to send me 2 and I’ll mail you 3 buffalo nickels

If you like nostalgia or are really cheap, you could use a nickel.

I actually have one car with a nickel for a core plug. Perfect size. I guess it would be OK in a pinch. My nickel doesn’t leak so it stays in.

I got the old plugs out. I'm glad I ended up taking some stuff apart or I wouldn't have realized how bad they were due to the aftermarket exhaust manifold blocking my view. Thanks for the offer for the buffalo nickels. I think I'm going to stick with the brass ones as the middle and rear plug holes have some pitting & I hope the brass will deform into a shape that will seal better when I install them.

I delivered the generator to Brent Mize this week. I had a great time talking with him & learned quite a bit while I was there.

Transmission bands are next and then it's time to tie into refinishing the spokes. Plenty to do this winter.

Boaski wrote: ↑

Sat Dec 30, 2023 1:46 pm

...the middle and rear plug holes have some pitting & I hope the brass will deform into a shape that will seal better when I install them.

Take Dan's advice, above, to apply some Permatex #2 sealant when installing the new plugs.