MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - 3-Main engine oil leaks

I recently had my 1964 MGB, 3-Main engine rebuilt after overheating and a subsequent seizure. The engine is now experiencing a significant oil leak from the rear of the engine. The oil stream appears between the rear engine plate and the oil pan. The spot on the ground is about 3 to 4 inches in diameter after an overnight park. The engine before rebuild did not drip a drop of oil. I know oil leaks are common on this engine, but I think that this is excessive. Am I correct? Does anyone know trick or two that may reduce the leak, preferable without having to remove the engine?
Frank Grimaldi

frank

no it is proberbly the cork seal between the sump and block that was not fit correctly or is damaged.
only way is engine out and replace the cork seal

ste
Ste Brown

The position of the rear bearing cap and the cork seal is critical. I rebuilt my 3-main engine myself, followed instructions on the Octarine website

http://www.octarine-services.co.uk/1.%20fitting%20the%20crankshaft.htm

and am very satisfied with the result.

Tore
Tore

That link did not work. Hope this does:

http://www.octarine-services.co.uk/

You find the pictures under "A picture guide to building an Octarine engine".

Tore
Tore

Tore,

Thank you for your response. I checked that site and could not find photos of the cork seal. Additionally, if I read the description correctly, the photos are for a 5-main engine (18V 847 type from 1976), whereas mine is the 3-main engine (18G, 18GA 1962 - 1964)

If I am mistaken, please advise.

Frank
Frank Grimaldi

Franck,

One practical way to prevent/cure this rear oil leak one 3 main units is described on "mga guru". Barney Gaylord describes porcisely how to instal a rubber seal even on the 3 main back plate as mentionned onto the link below.
"http://mgaguru.com/mgtech/engine/cs202a.htm"
Regards
Renou

Frank,

No, there is not a picture of the cork seal, but on several of the pictures you can see the groove in the bearing cap where the seal goes. If the bearing cap is not correctly aligned there may be a gap between the block and the backplate where a leak can develop, or the other way - the cork is not under sufficient pressure to seal properly.

My engine is an 18G, but this part of the engine is identical to the 5-main. I also used lots of blue Hylomar on the cork seal.

As you say the oil stream is between the engine plate and the oil pan, I don�t think an oil seal on the crankshaft will solve the problem.

Tore
Tore

This thread was discussed between 23/04/2008 and 25/04/2008

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now