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MG TD TF 1500 - Inserting New Core Plugs

My 1952 TDC MkII core plugs are weeping, so I have a bag of new plugs being shipped to me from Tom Lange.

Do you use any adhesive or lubricant when you insert your new core plugs? I have heard of fellows using a little silicone to make them slide in easily, with no adhesive. I have also heard that John Twist beds them in with a thin coating of JB Weld.

Adhesive or lubricant??

What say you?

Erick
EB Blackwelder

No lubricant.... Clean the seats perfectly clean.. the coat the opening with some JB Weld and then drive the plugs properly into place. If you haven't set the core plugs before, I'd recommend you do some research so you don't mess them up.
MG LaVerne

Can JB Weld be easily removed? I would be worried about it being too good. We used to apply gasket sealant (whatever that yellow stuff was). Easy to scrape out later.
Christopher Couper

I wouldn't use JB weld as it would make repairs problematic in the future. JMHO. Talk with Tom and get his advice since they are his design and I'm sure he has done change outs for customers on a fairly regular basis. The bores need to be as clean as you can get them. Either with a crocus cloth or ? I don't remember what we used on them when we installed ours
W. A. Chasser Jr

The JB can easily be removed later with a scraper or a power wire wheel. Gasket sealant used to be the standard, but I think due to the age of the castings and the toll that has been taken, the machining surfaces just aren't up to the task any longer. After several failures at least two done by very competent installers I've gone to the JB on the cores including the important one behind the cam and have not had any issues since. Just my two cents.
MG LaVerne

I always use "Araldite" which is an epoxy glue similar to JB Weld but without the metal powder content. The plugs thus fitted have always been easily removed if necessary. Assuming the replacement plugs are brass it will be a very long time before they will need removal!

Have you fitted a dished core plug before? Apply sealant, push it in and then start "panel-beating" it flatter. A big diameter, flat-ended punch will help. Keep flattening it until it is tight in the hole and then flatten some more. Stop hammering BEFORE the plug is completely flat. The aim is to have the plug finish up with a slight, even dish, Not a big dent in the middle.

Bob Schapel
R L Schapel

I would say it depends. Those of us lucky enough to have original core plugs, or an engine with only a rebuild or two, or where the hole cleans up well, can get away with some non-setting gasket seal like Hylomar. Then what else matters is how precise the core plug sizing is.
D mckellar

I used Permatex Copper gasket compound when I set mine, easy to wipe excess off after the plugs are set and they don't leak. Just make sure you use a small rotary wire brush to clean the seating area very good. It only takes enough sealant on the tip of your finger to color the seats in the block. I use an aluminum drift about 1 inch in diameter with slightly rounded edges against the plug, a socket of the appropriate size has been used many times. Don't push the center of the plug past the seat in the block, stop short. That's how I do it and never had one leak, even with the old steel plugs. PJ
Paul161

Perfectly clean seats, new brass core (Welch) plugs, Stag sealant & a good whack with the ball pein of a large engineer's hammer worked for me. Cheers
Peter TD 5801
P Hehir

I aiways use silicone gasket sealant and it seems to work very well.
Dave H
Dave Hill

I second LaVerne all the way. George
George Butz

Do not use silicone!
The professional engine builders use Loctite, # 540 or stud & bearing mount. Check with Loctite.
Remember they are metric, not inch.
Yes the center one under the exhaust manifold may need to be replaced with a rubber expansion plug, even if the OEM type was installed correctly,It may blow out for no reason.
Len Fanelli

Thanks gentlemen for sharing your experience with setting core plugs.

I'm replacing the plugs in my TDC because some are weeping coolant. I obtained genuine brass plugs from Tom Lange.

John Hambleton will be helping me remove the old plugs, and install all except the rear engine plugs. I will be taking the car to my pal, Big Dave, to use his engine hoist to lift the engine far enough out of the car to reach the rear engine plug.

While the engine is out of the car, I will replace the water pump, which has some loose bearings.

1953 MG TDC11267
2008 BMW 328i Last of the inline 6 cylinder engines.
EB Blackwelder

Peter,
I have been using the same method as you for well over 50 years and never had a failure.
We used "Stag: on the ships side bolts for overboard discharge valves and they had to be water tight otherwise there would have been a disaster of "Titanic"
proportions. Clean up is with methylated spirits.
John...Sydney
John Walton

I've used Loctite 586 which is a thread sealer with good results.

I sprayed the cleaned seats with zinc paint to minimize rusting.

On the picture you can see the flattened dishes of the plugs

Willem van der Veer

This is a before picture....

Willem van der Veer

and the cleaned and zinc painted seats

Willem van der Veer

This thread was discussed between 06/03/2016 and 08/03/2016

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