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MG TD TF 1500 - Engine Teardown

Taking a break from the chassis and suspension work so I dove into the engine. '54 TF XPAG and out of the car so easy access. Got the head, oil pump and sump off yesterday. Today was the crank, pistons and camshaft. Success on all though #3 piston was frozen and took some work to get out. Bearings and crank don't look to bad. The big hurt is that the freeze plug at #3 was clearly blown out so I'm nervous about block damage. Need to get to the machine shop for evaluation of everything.




RS Scardamalia

It's a common misconception that a "freeze" plug will pop out when a block freezes. The hole is actually part of the casting process, and a block can crack with all the Welsh plugs (their proper name) in place.

I would get the block magnafluxed, and am pretty confident all will check out OK. See mgtrepair.net for the good Welsh plugs, and other engine parts.

Tom Lange
MGT Repair
t lange

Engine and pan look pretty clean. Any idea of milage?

It is a good idea to have the block professionally washed. You may be amazed at some of the stuff they get out of the water and oil galleries. They can then review the block. It will also give you a clean metal to repaint.

Toms brass welch plugs are the way to go.
Bruce Cunha

With the sump off I would recommend re-locating the jiggle pin 1/2" further back and plugging the original hole.
Regards
Declan
Declan Burns

"The hole is actually part of the casting process, and a block can crack with all the Welsh plugs (their proper name) in place." They're actually called Welch plugs. The Welch plug was originally designed in the 1900s at the Welch Motor Car Company in the United States. Cheers
Peter TD 5801
P Hehir

Damn - fat fingers again. Welch it is.

Tom Lange
MGT Repair
t lange

Thanks for the suggestions. Expecting to take everything to a local machine shop experienced with MG's. Will have the block tanked and magnafluxed along with the crank. Cylinder head will need redone also. I don't see any signs of previous milling and suspect the engine has never been apart.

Resources aren't unlimited and I'm basically looking to get the car back to being a driver - nothing special. But... are there modest improvements that can be made now since everything is broken down?
RS Scardamalia

For information, the term used for these plugs in British English is "Core plugs" "A Core," in casting terminology, is the part which is used to create cavities in the cast. Attached is an example.

John

J Scragg

The core plugs are in place as a way to remove the sand that formed the "core" or void in the block after the casting process. The "block is often cast solid and that area is made to be broken out with a hammer and cleaned before machining. That void generally is used for coolant.
J Stone

DECLAN.
I thought that I knew all the bits and pieces of a XPAG but what or where is the JIGGLE-PIN on that engine?
Sandy
Sanders

I’ll see if I can beat Declan to that one. There is a hole in the bottom rear of the sump casting that allows some of the underbody anti corrosion fluid that is forced past the oil retention scroll to escape. The jiggle pin is inserted to help keep the hole clear from a build up of muck. By moving the hole further back it makes it easier to align a catch tank that reduces the distressful evidence of the inherent incontinence of the XPAG.

BTW I am currently fabricating such a tank and was wondering whether to leave the jiggle pin out as there will be considerably less chance of the hole getting clogged up with the tank in place.

Chris
C I Twidle

That was my thought too Chris. Just the big split rivet. I have heard that it is possible to install the original cork or the newer Nitrile sump gaskets, using great care, especially in locating the 'ears' at the rear so that there is no leak. Is this possible? Cheers
Peter TD 5801
P Hehir

It’s the weep past the scroll that comes out there. My sump appears to be leak free with just the original cork seal.
Chris
C I Twidle

I really appreciate these threads. There are so many t-series experts. Like many people, I used to think the core plugs were anti-freeze plugs. I also appreciate the humor. I had always wondered the purpose of the small amount of fluid that came out of the rear of the sump. Now I know it is anti corrosion fluid.

Thanks to all
Jim
JV Smith

This thread was discussed between 04/10/2020 and 06/10/2020

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