Best practices on installing core/freeze plugs?

[ronstory]

During my rebuild, I had replaced all 6 core plugs (from MMI) on my rebuild for the block, head and manifold. I now have 2 of the 3 small (7/8" plugs) weeping a bit, one in the head and one in the manifold. I cleaned and inspected the seat, make sure the plug was snug in pocket before flattening.

I used Permatex #1 (hardening sealer) in the pocket and then drove in plug with a socket to support the out rim while driving in. Then I flattened the center with a smaller socket and hammer. Then I waited a day for the #1 to harden and repainted.

Looking at the A4 360 deg pics on the MM site, I notice they look to have single dimple in the core plug on the manifold.

So any hints on what works best on the smaller plugs? I'm 3 for 3 on the large plugs but only 1 for 3 on the small.

[Dave Neptune]

Ron, I don't really know all about freeze plugs. Driving one in with a socket is a very good practice. I was taught to "set" smaller ones with one or two centered strikes and used a rounded punch. With the larger ones I use a ball-peen hammer and use the peening end again with a couple of strikes. I was cautioned to not over-do the striking as it could damage the seat that the disc seals. Never had a problem with one if the hole was in good shape and usually let the "shop" doing the dipping and inspecting install them for me.

Dave Neptune

[romantic comedy]

Back in the 70s we used to epoxy in the plugs on the auto to marine conversions.

[ronstory]

Thanks Dave & RC! I'll just go for a few whacks in the center versus the fully flatten. Ken at MMI mentioned putting a fillet of JB Weld on the outside of the seam of disc for extra protection.

I got my parts and my new MMI manifold. The last manifold had a leak through the stud due to PO drilling through lower stud threads to put in a helicoil. Of course it didn't develop the leak until after I had the motor installed and ran thru 2 sea trials. Now it's "inconveniently located". (sigh)