soft plug leaking

[Michael Oritt]

Dale--

They are not freeze plugs--the holes are used during casting. I wouldn't be concerned about the plug's not being able to pop--the radiator cap will take care of letting out excess pressure.

And yes, as Steve G showed it is the Dorman two-piece plug (Not Belcamp) that I was thinking of. I, and many racers, use them in preference to the convex ones and when properly installed in JB Weld or similar they do not blow out.

 

[blueskies]

Wouldn't the BN7 engine have cup type plugs rather than the type you have to dimple?

Danny

The new ones that I installed in the BN4 are the dish type that you have to dimple. One uses a ball peen hammer, or a combination of a punch and hammer, to hit the plug in the center to expand it. That also creates a dimple.

As extra insurance against leakage, I added a little JB Weld to the edges of the plugs. I am more concerned about leakage than about freezing the block. If the block froze, even if the frost pushed a few plugs out, the block likely would also crack. Better freeze protection involves having an adequate anti-freeze mix in the system. If the plugs ever need to come out, it would not be difficult to clean off the epoxy.

For anyone not familiar with JB Weld, it is wonderful stuff, with its use limited only by one's imagination. I once had an oil leak at the rear of a newly installed Chevy big block manifold. Feeling lazy, I just cleaned off the oil and applied J.B. Weld. Years later, it's still holding. Another time, overzealous tightening of a temp sending unit cracked an intake manifold. As a temporary measure until I could find a replacement, I ground out the crack, added JB Weld, and sprayed a little paint on the area. It looks perfect, and the correct replacement manifold is still gathering dust. J.B. Weld also works for things such as filling in nicks in boat props and boat legs. A little paint over top, and it looks as good as new. (One would think that I owned shares in the company; I do not.)

 

[Jim 58 BN6]

JB Weld is great stuff, and I also like PC7.

I have yet to take the engine out of my Healey, so the core plugs I'm familiar with are not the kind you dimple, but are cups, with short sides. They saved my brother's Ford 390. He had anti-freeze, but we were teenagers, and didn't realize the mixture was only good to about 0F. It got a lot colder than that, which is unusual for this area. Two left-side plugs on the block popped. We thawed it out, replaced the plugs (in MISERABLE weather, laying underneath the car with no garage). Fortunately there was no further damage. We then invested in a cheap Prestone hydrometer that I still have. So, yes, I agree having proper anti-freeze is the only solution (pun intended!).

I've seen the domed plugs on the rear of V8s, blocking the rear camshaft bore. I never remember replacing the plugs on a TR, FIAT or ALFA, but now, I find myself not remembering fairly often...

 

[CaptRandy]

I know the use you are using does not contact gas but I did contact JB Weld about their product use with ethanol gas and they said they had not incurred any problems but I still wonder how it reacts with the E-10 gas. Fiberglas resin is compromised with E-10, the glass is fine but the resin in joints and surfaces becomes porous.

 

[Patrick67BJ8]

Dale--

They are not freeze plugs--the holes are used during casting. I wouldn't be concerned about the plug's not being able to pop--the radiator cap will take care of letting out excess pressure.

And yes, as Steve G showed it is the Dorman two-piece plug (Not Belcamp) that I was thinking of. I, and many racers, use them in preference to the convex ones and when properly installed in JB Weld or similar they do not blow out.

I've always called them freeze plugs but was told by an old timer mechanic that were casting plugs too, but if you don't call the freeze plugs most people won't know what you're talking about.

 

[Keoke]

Patrick said :
I've always called them freeze plugs but was told by an old timer mechanic that were casting plugs too, but if you don't call the freeze plugs most people won't know what you're talking about.

 

[CaptRandy]

From the 50s and 60s they were freeze plugs.

 

[Dandare]

The new ones that I installed in the BN4 are the dish type that you have to dimple. One uses a ball peen hammer, or a combination of a punch and hammer, to hit the plug in the center to expand it. That also creates a dimple.

As extra insurance against leakage, I added a little JB Weld to the edges of the plugs. I am more concerned about leakage than about freezing the block. If the block froze, even if the frost pushed a few plugs out, the block likely would also crack. Better freeze protection involves having an adequate anti-freeze mix in the system. If the plugs ever need to come out, it would not be difficult to clean off the epoxy.

For anyone not familiar with JB Weld, it is wonderful stuff, with its use limited only by one's imagination. I once had an oil leak at the rear of a newly installed Chevy big block manifold. Feeling lazy, I just cleaned off the oil and applied J.B. Weld. Years later, it's still holding. Another time, overzealous tightening of a temp sending unit cracked an intake manifold. As a temporary measure until I could find a replacement, I ground out the crack, added JB Weld, and sprayed a little paint on the area. It looks perfect, and the correct replacement manifold is still gathering dust. J.B. Weld also works for things such as filling in nicks in boat props and boat legs. A little paint over top, and it looks as good as new. (One would think that I owned shares in the company; I do not.)

Sorry blueskies, in my post I mistakenly put BN7..I meant of course BJ7 which is the OPs car I think. The point I was trying to make is that aren't the 2.6L heads and blocks the ones with the dished plugs and the 2.9L the cup type?

Danny

 

[blueskies]

Sorry blueskies, in my post I mistakenly put BN7..I meant of course BJ7 which is the OPs car I think. The point I was trying to make is that aren't the 2.6L heads and blocks the ones with the dished plugs and the 2.9L the cup type?

Danny

You are correct, Danny. I just checked a BJ7, and it has the cup type plugs. I have not had to install that type on a Healey, but likely would be tempted to use a little sealant or epoxy compound as insurance on them as well if I had to replace them.

 

[Michael Oritt]

Another problem with the dimpled kind is that in order to install them correctly you really need to use a drift and, as BlueSkies says, take a good whack at them to put in a dimple. That is easy to do when the engine is out of the car but quite difficult with it in situ. I have twice had disc plugs blow out of the Elva's MGA engine during an event and replaced them with Dorman units. They never gave me any trouble and I now install them in all engines in preference to the cupped plugs. Some people put bar straps over them which they bolt to the engine.

 

[oxford]

Welch plug?

 

[MisterB]

https://holdenpaedia.oldholden.com/Welch_Plug
Who knew?

 

[Jim 58 BN6]

Now that you guys mentioned "Welch" plugs, I believe that's what they were always called in the Triumph repair manuals.

 

[RestoreThemAll]

With the issues fixed the engine started after cranking about 6 times, and ran smooth! That's the first time that car has run in decades! I'll post a different thread on that. After calming down from the excitement I pulled the head and installed a new casting form plug aka freeze plug. Stock plug with JB weld. The hole was pitted. Cleaned up with fine emery cloth and brake cleaner.

Thanks everyone for the help and great discussion.

 

[busybrit]

This as another problem I've seen.

Clean off the green paint with brake cleaner on a rag, rough up the metal and like "blueskies" suggests cover the plug with epoxy sealer.

Permatex make two, one for water and one which is called steel. The steel has tiny fiberglass partials in it so I was informed, as well as a black die to differentiate it from the water seal product which is white.

The company told me they will both work. I've poked a hole through a rotted freeze plug and filled it with this product and as yet over 10k miles it's still holding. So your tiny weeping wouldn't be an issue.

Johnb

 

[DTDuck]

Dale--

They are not freeze plugs--the holes are used during casting. I wouldn't be concerned about the plug's not being able to pop--the radiator cap will take care of letting out excess pressure.

And yes, as Steve G showed it is the Dorman two-piece plug (Not Belcamp) that I was thinking of. I, and many racers, use them in preference to the convex ones and when properly installed in JB Weld or similar they do not blow out.

These are indeed freeze plugs and yes they are the result of the casting process, however the reason that all manufacurers use them is for freeze protection. When water/coolant freezes it expands and is very powerful. if it is inside your block unless it has somewhere to go it will destroy your engine, crush the cylinders and most likely crack your block and head. Removing the Radiator cap will not help on this as the water/coolant inquestion is not in the Radiator, it is inside the engine. I have seen it where all the freeze plugs were popped and a big icicle sticking 6" out of each one. PITA, but it beats a destroyed engine.

Regarding the Bars Leak and Alumaseal idea, don't do it. Those are stop-gap emergency repair products. Use them in your 20-year old beater to get a few more months out of it, but I would never, ever put anything like that in a fresh restoration.

Cheers,
Dan M.

 

[blueskies]

DTDuck, Agreed that the plugs may pop out if the engine does not have coolant in it and the water freezes solid. But the block can crack anyway, even with "freeze" plugs in place. How many thousands of boat owners with inboard motors (who did not get around to winterizing the boat) and owners of vehicles that had water added "temporarily" find that out the hard way each year when the temperature drops??

 

[RestoreThemAll]

Dan,
I agree with the temporary fixes used only for the older daily drivers, and not my newly rebuilt engine.

I did remove the head. Added a new "freeze plug" and reinstalled with a new head gasket. I scuffed and cleaned the plug hole hospital clean, and put a small amount of JB Weld. I have it almost ready to add water and start it so we'll see if it's fixed.

I'm not concerned with the engine freezing. I will drive this car often but it'll be stored in a semi heated garage and will have fresh antifreeze in the engine. Who on this forum wouldn't have fresh antifreeze in their car?

Dale

 

[Bob_Spidell]

... Who on this forum wouldn't have fresh antifreeze in their car? Dale

The racers. I believe it's verboten on tracks because if it's spilled it's very slippery (might be fun in a drifting contest I suppose).

 

[Jim 58 BN6]

The racers. I believe it's verboten on tracks because if it's spilled it's very slippery (might be fun in a drifting contest I suppose).

I can vouch for its slipperiness, not in racing, but due to falling flat on my a** after stepping into some that I had spilled...