What size block core plugs and how to seal them?

[cjshaker]

What size core plugs do you engine builders use, and how do you seal them when you install them? I'm talking about the block water jacket plugs. I'm assuming I can find them in McMaster Carr or something similar and need to get them ordered. I know this was discussed in Mr. Foxwells engine build thread, but apparently he didn't want to be helpful to anyone and had all his threads deleted.

[blykins]

Doug, are you referring to the drive-in freeze plugs?

[cjshaker]

Yes, the ones that go into the side of the block.

[Barry_R]

We use 1-49/64 brass plugs with TA-31 silicone (you can use any of your favorite sealers - they all work - I know some guys even use epoxy)

[C6AE]

I use the 49/64 brass plugs and loctite...

[cjshaker]

Thanks for the replies. In case anyone is interested, the Dorman part # is 565-036. My local Napa couldn't get them, so I ordered them through Summit, in a package of 10. I always have a couple tubes of TA-31 around since that's what I use on most gaskets.

[CaptCobrajet]

I don't use any type of silicone there.  It just lubricates it good for exit!  Clean well and green Loctite. (sleeve retainer)

[cammerfe]

I know where to borrow a proper-size tap, so I thread them, use brass plugs and put them in with epoxy. (Extra support by doing so.)

KS

[blykins]

I use silicone.  I've been using Dow Corning 732 for a few years now for pretty much everything.  Little bit around the outside edge, drive her in, and I'm done.  I can't recall ever having a freeze plug come out, but I've had a few blocks where the holes were a hair oversized for some reason and I've had to use metric plugs. 

[GJCAT427]

I`ve used good ole Permatex aviation sealer (the brown stuff) for years. Never had one pop out yet. I got my core plug from Pioneer and got the ones for FEs by correct size.

[Joe-JDC]

X-2 on the Permatex sealer.  Joe-JDC

[cammerfe]

By all means, use the brass plugs. I had a steel one rust through once on a 460, behind the engine mount. Bitch to fix it!

KS

[C6AE]

Put a magnet to those " brass" plugs.
More than once I have been sent brass plated plugs...

[66FAIRLANE]

Put a magnet to those " brass" plugs.
More than once I have been sent brass plated plugs...

Thats good advice right there!

[427Fastback]

Personally I would never use silicone on them for the stated reasons.I would use permatex or gasket cinch on them.That being said I have never had one come out regardless of what was used when they were installed.