The Stovebolt Site Forums The Shop Area Engine Shop freeze plug, front of 216

Tried filling the radiator of my non-runner 216 for the first time today and noticed my feet getting wet. Turns out the front freeze plug was missing. Pulled radiator and fan and found the plug on top of the gunk in the radiator support - it is the steel disk kind, mostly flat with slight convexity in center.

Previous threads are helpful, but still a couple Questions:
1. is a blown freeze plug a symptom of anything particular to check, or should I just replace and see what happens? Would you guess it blew running or froze while parked in winter?
2. Is it important to find the same type plug? Napa and the vendors only seem to have the cup type or dome-shaped. Brass or steel? Use the old one?
3. any good tricks for cleaning the rust in the hole and setting the plug? Previous threads say put in freezer before installing, use a socket to hammer it in and seal with permatex 2.

It will be the domed type and when installing you tap on the front of the dome so that it spreads out and seals. There will be a ledge inside the hole in the block that it will stop against. I like to use some sealer too. In my case, after the one on the front of the motor failed, the one in the rear did the same thing. They were old and rusting around the edge.

Thanks, is it this one?

http://www.napaonline.com/Catalog/CatalogItemDetail.aspx?R=SEP3811026_0204451081

The description seems right although I don't know the size off hand. The photo looks a bit odd because it doesn't have sides to it. I think the photo is either generic or there is a shadow from the flash that looks like it has a side to it. Anyways, calling it a disc is how I would describe it.

That core plug from Napa looks too thick. I guess it is cheap enough to purchase and find out. Otherwise the usual online vendors sell the plug as part of the plug "kit". Never bothered to look for it individually.

I have used plugs as thick as the one shown above, and I have used thinner plugs. Depends on the location on the block, and it depends on the source of the plug. These are not the right sizes but it shows the variety of designs that are vailable. I have seen many designs of plugs used on 216/235/261 engines.

Clean the hole in the block with a wire brush (on a drill or dremel tool). Some people use no sealant, and some people suggest using sealant. I have installed the plugs with and without sealant. I prefer using sealant.

From Chevs of the 40s - soft plug set - block casting plugs, expansion plugs, etc

Well I got the NAPa domed steel disc type. It was a good fit, but there is no lip to hold it in. Tapped on the dome, but have no idea if it will hold - doesnt inspire much confidence...

I guess tapping was a poor description. You have to hit the centre of it so that it spreads the side and forces it out in the bore. One technique is to place a hammer against the plug and hit the hammer with another one.

Thanks. Will try one big whack with a big hammer on a smaller one. Seems like the trick is to hit it hard enough to "dimple" the center and spread the plug, but not so hard to distort it and cause a leak. About how much of a dimple works well - dime size by 1/8"? bigger, smaller?

NAPA only sells bags of 10, so if it fail, at least I have spares, but would rather avoid that!

In a perfect world you would have a tool that had the exact contour that would result in a perfect curve. Since that is not the case, I would think that spreading out the force as much as possible would be a good thing.