Bad Frost plug hole

[altair]

I made my own plugs with some scrap lead and stainless steel bolt, washers and rubber O ring. They squeeze up tight and don't leak.

[cwsimpson]

I think your best bet is to get a Good Seal Installer Tool (the kind with the long ball swivel handle to accept different sizes of drivers) to drive the Domed 1 1/2 Inch Brass Core Plug absolutely FLAT! That is the trick, any "Dimpling" in or out, will ruin the job.

You have to keep in mind that the "Seal" is dependent on the Very THIN Iron edge between the outside surface of the Block and the Shelf/Ridge that is damaged, so the broken Ridge is not as big a deal as it may seem.

Of course thoroughly CLEAN the surfaces and use good Permatex #2 Sealant.


The "Other" problem case is on the Full Flow Blocks, when you find what I have on replacing the CUP type Core Plugs, where portions of the Ridge from the Old configuration still remain because they did not fully cut them out which keeps you from getting a good amount of the sides of the Cup sealed on the Block and a flush install.

Thanks for the info! I''ll certainly look into it. Some guys say "just hit with a punch." Of course, part of time they might be talking about a different plug style! Kinda gotta be careful with some of this. Best to keep it as close to original as possible, but sometimes life gets in the way and things just don't go quite right.

[cwsimpson]

Clean off the rust, get a size that expands beyond the round area, and deep enough to pass just into the hollow area, it will easily cover up the rough area, and even balloon out behind and past it. Tighten it up it will seal-take our word for it, used my first (and only, thankfully) on my 63 Hawk in 1968-over 100,000 miles of abuse after installing -never leaked. They've been around for 50 plus years because they work. Secret is to get the size that just barely fits the round part going in.

Thanks for the additional thoughts and instructions. Everybody here has given me a lot of ideas to try. Hopefully, once I get the bum hole fixed the others will go in a little easier, or at least be a better fit.

[doofus]

CW there are copper bolt in plugs, you hold the center large bolt,part of plug, and tighten smaller nut to spread into place. works in early and late blocks. only problem is need thin "Tappet Wrench" to hold body as you tighten. Luck Doofus

[Rerun]

I have used the brass Dorman expansion plugs successfully when part of the lip is missing. As long as there is enough of a lip to hold the plug square during tightening, it should be OK.



Otherwise, I would grind out the remainder of the lip and go to a cup type of plug. I would advise against using the rubber expansion plugs, especially without first grinding the rest of the lip away.

[BILT4ME]

If you are using the brass cup or zinc plated style core plugs (freeze plugs), they are domed (convex) on one side, and cupped (concave) on the other. The DOMED side goes to the inside of the engine, so you can see the cup side and the part number from the outside.

Clean the inside edge of the HOLE with Scotch Brite or LIGHTLY with a mild emery cloth (200 or higher) to clean the surface. Wipe the surface of the hole with a lint-free rag (old T-Shirt) soaked in brake cleaner.

If the plug is too LOOSE, you must tap it on the DOMED side to expand the outside edges of the plug. Just use the hammer with the core plug setting flange-down on a hard smooth surface such as concrete or steel, so the dome is up. Strike the dome in the CENTER once or twice enough to push the dome down slightly. Repeat this step until the plug appears to be oversized for the hole.

If it is too LARGE, then you use a smaller punch to insert it and drive it into the block (no smaller than 3/4" diameter) or you may poke a hole through the core plug during the installation process.

At NO time should someone dimple the edges of the HOLE in the block or the edges of the flange of the core plug.

Prior to inserting the plug, brush on some Permatex #2 or Indian Head gasket shellac compound on BOTH the inside of the hole and the outside flange of the core plug. DO NOT USE SILICONE SEALER. Then use a seal driver of a deep well socket that just fits inside the cupped (concave) side of the plug. Lightly tap in the core plug EVENLY and deep enough just so the TIP of the cup flange is FLUSH with the OUTSIDE of the block.

If anyone has any additions or corrections to my methodology above, please advise.

[StudeRich]

Mark, have you read the proper procedure in Post #14?

It is way simpler than your method, no need to ever distort the original shape, just put it in the hole and FLATTEN it, it's that simple.

Also I think this got typed backwards, the Dome goes Outside:

QUOTE: "If you are using the brass cup or zinc plated style core plugs (freeze plugs), they are domed (convex) on one side, and cupped (concave) on the other. The DOMED side goes to the inside of the engine, so you can see the cup side and the part number from the outside."

[BILT4ME]

Was this changed in orientation of any of the engines? My 59 259 V8 block and my 63 259 V8 block all have the dome to the inside. As I see it in the manual (unless my pictures are truly distorted) the dome goes to the inside. From a physics standpoint, the dome must go to the inside, as the plug is designed to withstand pressure and to keep the plug in place. Since it is not welded on, the pressure on the back of the dome pushes the flange out, making the plug tighter in the hole. If it was reversed, the pressure would be on the inside of the dome and make the plug fit looser and it would blow out.

Technically, you shouldn't need a sealer....If it's clean enough and done properly and PO didn't screw it up for you......

My installation description is the same as yours except that I didn't use the "proper tool" made for doing it. The following video shows what you describe. Please note that the dome is to the INSIDE of the engine. You don't flatten the core plug. It needs to remain domed if it is designed that way.

https://www.youtube.com/watch?v=ux52GfzYJTI

Are we talking about the same thing here? 'Cause I do this with my wife all the time........ It never ends well.



If need be, I'll delete my posts and copy verbatim from the manual so there is no doubt. I wouldn't want to have any mis-information here. (Seriously, I'm not trying to be a d***.)

I tried to delete the picture of the bright brass plug. It is installed correctly, but is a serious optical illusion.

Mark, have you read the proper procedure in Post #14?

It is way simpler than your method, no need to ever distort the original shape, just put it in the hole and FLATTEN it, it's that simple.

Also I think this got typed backwards, the Dome goes Outside:

QUOTE: "If you are using the brass cup or zinc plated style core plugs (freeze plugs), they are domed (convex) on one side, and cupped (concave) on the other. The DOMED side goes to the inside of the engine, so you can see the cup side and the part number from the outside."

[TWChamp]

Make sure which style core plug you are referring to when you mention the "dome". The cup style as show just above has the dome in and the side of the cup does the sealing.

The disc style has the cup facing out and when you strike the center of the dome it spreads the diameter enough to lock it in place

[gordr]

The two styles of core plugs are disc-style, and cup-style, and the latter can be found in both shallow and deep versions. The disc style can only be used in a stepped hole that is made for it. The step in the hole supports it when the disc is hammered flat, which makes its diameter expand, and seal the edge of the cup to the large diameter of the stepped hole.

The cup style seals like a cork in a bottle, and is simply drive in flush with the outer face of the block. I use sealant on both types, but I expect new plugs in a new block didn't need it. I use a socket that fits into the cup to drive them in, not having the special tool. Start them square, and it's easy enough.

The rubber expanding plugs have enough range to them to work in either plain or stepped holes, and damaged holes, usually.

[StudeRich]

Make sure which style core plug you are referring to when you mention the "dome". The cup style as show just above has the dome in and the side of the cup does the sealing.

The disc style has the cup facing out and when you strike the center of the dome it spreads the diameter enough to lock it in place

The ONLY Installation instructions that any of these posts are referring to in this string are what cwsimpson asked for: a 1955 Block with Disc Type Core Plugs as used on All Stude. V8's up to mid 1962 at the Full Flow Block change. Except in Post #21 which is apparently about the Cup Type used on Late '62 to '64 Blocks and not applicable to this string.

[doofus]

But still interesting to see how others install the core plugs,both disc and shallow cup. i also put sealer around edge as some holes can weep antifreeze months/years later, BTDT. i'm with the folks who drive the shallow cup in with a socket.i have a solid brass chunk that works on the disk type, all this with engine out on stand. in car r&r i use copper bolt in plug and sealer. one badly rusted hole got brass plug (flat disc) and JB weld as sealer.10 years and no leaks! Decades ago had flat disc fall out at 78mph on interstate! coasted into truck stop and allowed engine to cool somewhat. wrapped plastic bag around stubby flat tip screwdriver and shoved into hole.left cap loose and continued on, replaced with bolt in copper plug that afternoon. Happy Motoring , Doofus

[BILT4ME]

Rich:

Thanks for clarifying the difference in change.

I did not realize there was a change over point from a true disc type to the cup style on the V8's. My mistake.

In the case here, where the lip inside the block has broken off, can a cup style core plug be used IN PLACE of the disc style? I don;t see why not, since most of the other makes of autos have holes with no lip, but they all use cup style.

When I recently replaced the core plugs in my 1963 block, many of the holes still had a partial lip around the hole on the inside. I was tempted to remove the lip, but chose not to because there had already been cup style in it and I was concerned that if I started breaking them out, I may break out a chunk of the block wall.

Is there a wall thickness change in the block from the early blocks to the later full-flow blocks?

The ONLY Installation instructions that any of these posts are referring to in this string are what cwsimpson asked for: a 1955 Block with Disc Type Core Plugs as used on All Stude. V8's up to mid 1962 at the Full Flow Block change. Except in Post #21 which is apparently about the Cup Type used on Late '62 to '64 Blocks and not applicable to this string.

[StudeNorm]

Seems like a lot of discussion for a fairly simple subject, at least as far as installing cup style core plugs... Mind you, I have never even tried to use the disc style.

Over the past couple of years I have replaced at least 6 core plugs between my '63 Lark and '63 Avanti. The worst one was the center right side on the Lark. I use NAPA 1.5" and/or 38mm plugs (they both work fine). I also use Permatex Red to provide a lube and then a sealant at the joint. And I use fine sand paper and steel wool to remove any "varnish" or old sealant from the bore holes once the old plug is out.

I have always found that I could drive the old plug into the water jacket and then remove it with pliers once it is loose. Just use a brass punch so there is no possibility of scoring the machined surface. A coat hanger and flowing water will clean and flush the crud that settles in the water jacket. It does get messy, though.

I always try to start the plug using the socket method as stated above. I have gotten one kinked and ended up having to use the rounded end of a long extension bar to straighten it out but even it still worked fine afterwards. Once they are part way in I seat them using an oak wood block and whatever I can get in to the space to provide a solid blow to my piece of oak. I drive the wood block until it, and by extension the plug, is flush to the engine block. I find that oak works best because it essentially self-levels the plug into the hole without having the plug lip gouge the wood. Do not use a softwood block!

I have not tried to remove any block material 'lip' that sticks up higher than the machined surface on the inside of the block. It seems the machine work is deep enough not to allow interference with the plug so long as I don't over drive the plug into the hole.

I have never had a problem with these plugs even after having a couple of over-heat incidents. Make sure you have a good 15psi rad cap installed.

[cwsimpson]

The two styles of core plugs are disc-style, and cup-style, and the latter can be found in both shallow and deep versions. The disc style can only be used in a stepped hole that is made for it. The step in the hole supports it when the disc is hammered flat, which makes its diameter expand, and seal the edge of the cup to the large diameter of the stepped hole.

The cup style seals like a cork in a bottle, and is simply drive in flush with the outer face of the block. I use sealant on both types, but I expect new plugs in a new block didn't need it. I use a socket that fits into the cup to drive them in, not having the special tool. Start them square, and it's easy enough.

The rubber expanding plugs have enough range to them to work in either plain or stepped holes, and damaged holes, usually.

gordr-
Thanks for the input.
Indeed this is the type Rich has described (disk). I was out trying to install one this pm with bad results. Seems quite difficult to hit squarely when the engine is in the car. There may be a way to find everything that fits underneath just right for a good thump, but right now, I see a lot of frustration. Tough part comes when you try to flatten the plug and there just isn't a way to hit square. I tried a seal set- just can't get the right angles. While I like to run the original setup, if possible, I've gotta stop and give this some thought here. Thanks everyone for the input. And, yes, it does seem to be a lot of talk for something that is sometimes considered run of mill. Originally, I took out the first plug because of antifreeze leak on the passenger side of the engine. Looked like it was weeping out of the plug but while I was working on that plug, all of sudden it had antifreeze on the outside- must have come from underneath the exhaust. Got that sinking feeling. (All of the antifreeze has been removed, yet there is still some oozing out from somewhere in the engine.) Since all of the antifreeze was out, just figured I'd remove the remaining two plugs and flush 'er out. While part of that has been done, this is on hold until I figure out which frost plugs to use. Right now I'm leaning toward the rubber expansion. If it doesn't stop the antifreeze leak, the work will have to go deeper- probably a head gasket on that side and hopefully not a cracked block. But if we're doing one side....might as well be bold and do both since I've got a new set of heads I can drop in. Just getting pretty hung up on the frost plug details right now. That's a little challenging but the bigger picture is that antifreeze is still running out on the outside of the suspected plug,even with a new one fitting loosely in the hole.... Again thanks everyone for the input. Apologies for any frustration coming through.