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MG MGB Technical - Trying to determin which engine I have

Hello,

I bought a 1950cc engine last year in the UK, which I had shipped to Canada. I'm trying to match up a 5 speed transmission to it, but I am not sure which engine I have. (3 bearing, 5 bearing, 18V) The head is not on, but the rest of the engine is together. Is there anyway to tell what engine this is, without taking it apart? (there is also no serial number on it)

Thanks,

Jason
Jason

Three bearing engines and early 5 bearing engines have a squared off backplate and a small, thick flywheel whereas later 5 bearing ones have a more rounded backplate and a larger thin flywheel.

18V engines have small cutouts at the top of each cylinder. They also have a small plate bolted onto the lower left side of the block for a mechanical fuel pump.

18 G - GK engines have a long nose water pump, 18 V ones have a short water pump.

18 G/GA engines (3 bearing) have Head casting numbers 12H206, 18 GB (5 bearing) to 18GK engines have 12H1326, early 18V engines have 12H2709, late 18V have 12H4376.

All engines share the same bellhousing pickup points - the only major difference is the flywheel (which is interchangeable together with the backplate on all engines) and the diameter of the spigot bush - small in the early engines but some way through the 3 bearing production went to a larger (.825inch) diameter.

Chris at Octarine Services

If you're using a five-main engine and intend to use a 5-speed transmission, I had excellent results using a Rivergate kit to couple an 18GB engine to a Datsun 280Z transmission for my Magnette saloon. Check out their website at:
http://www.rivergate5speed.com/rivergate.html

This is a really well-designed, beautifully built kit and it goes together as easily as reassembling stock components.

My 2¢ worth...
Allen Bachelder

This thread was discussed between 01/10/2003 and 02/10/2003

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