Rear freeze plug lets go!

After finally getting the 72 B on the road after three year restoration I am blissfully driving to work when a cloud of water and steam appears in the rear view mirror. I pulled off the road with out the car heating, I had chosen the route carefully since I knew the car might be planning some outrage. It was my machinest who commited the out rage he did not replace any of the freeze plugs when they cleaned the block. I reviewed the form but it looks like a massive ordeal to do the right job. Can this plug be replaced with out pulling the engine. Had no luck with the rubber plug wont fit be hind the rear plate, could not find any copper seals locally. Any ideas would be welcome.

bummer... but I think it can be fixed with the engine in the car. It involves a new plug that is pushed into position with a large bolt through the hole in the backing plate .
The bolt is held in position with some large washers .Someone on this board has made one and I have seen the photos . Hopefully they will chime in .

good luck.

A thread on this subject was running just a few weeks ago. See the procedure here.
http://mgaguru.com/mgtech/cooling/cool_105b.htm

Clifton

First I have to ask, what kind of machine shop would rebuild an engine without replacing the freeze plugs!? Did he bother to even clean out the oil passages? Sounds like a shop that's used to re-building modern engines that don't require the special attention like our our old B engines do. Of course it's always the rear plug that goes! You may be resigned to pulling the engine (at least far enough out of the car that you can access the offending plug). I'm in the process of rebuilding my engine right now and I'm going to install a set of the expandable copper freeze plugs that you can find out there on evilBay from time to time for about $25 per set. You may be able to find them from other venues as well. I think the key to a good seal is a clean bore to install them in. The copper plugs expand with the tightning of a wrench and don't require any hammering to drive them home. Good luck!

Shawn Escue

Mike,

If you need moral support and guidance, I can walk you through a pretty easy fix.

Jimmy

we have all been here and have learned that good and cheap are two different words and not the same....

Never heard of them, Shawn. How do they work?

Yes, I did it. 1-5/8 plug, bolt, nut, washer, locktite.

Peter, the plugs have a nut on the outer face that, when tightened, causes the plug to expand and tighten in the hole. Kinda like a drywall anchor. Very simple concept really. I haven't rebuilt my engine yet so I haven't had a chance to try them out. I've heard lots of good things about them however. I think they're popular with some of the racers out there. I can't remember but I think that there was a discussion about them sometime back on this site. It may have even been my own post! Guess I'll do a search and see what I find.

Shawn

I missed this thread earlier. It was me that this happened to also, but during my first 5 minutes of break-in run. Anyway, I used the Betson bolt as illustrated, and it has held tight. I wish I could say the same for the rear side and middle plugs that my machinist did replace--incorrectly. See my latest thread, Core plugs revisited.

Mike

comart45 Wrote:

I just bought 2 of the 1 5/8 inch copper plugs from NAPA. The NAPA part number is BK 6004028, about $4.00 each.

Mike

Forgot to mention, the copper plugs cannot be used for the rear core plug, they are too deep, wide, thick, whatever to fit between the block and the rear plate. You need to use the stock type for the Betson bolt fix. Here is a picture of the side one.

(mbarjbar) Mike is a pro at this. His professionally rebuilt motor blew all but one. And no, it was not compression that blew them out, it was the high end shop that did not install them properly. I feel bad for him he spent big bucks on that rebuild. Ask him who does the best freeze plugs in California and the other states.

Thanks, Dan, it good to be expert (reluctantly) at something.... BTW, I have much less steam coming out of my ears over this situation. The car is running great and I am happy.

Mike