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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 Midget and Sprite Technical - Engine Bearings

I'm stripping my Marina based 1380 and building a list of the bits I need. I want to replace the big end and main shells.

The reference on the current ones are :-

Mains - S1229SA
Big Ends - S2123SA

I cant find anywhere to easily x-ref the various a series engines. Are they interchangeable with the Mini variants ?

For example this page
http://www.aptfast.com/APT_Parts/Aseries_Parts/a_Bearings.htm
suggests that I can simply go by the journal sizes and all should be OK. The marina should be the non-A+ variants...but can anyone confirm ?#

( I could wander into my local factor...but I suspect asking for marina bearings will lose me credibility ;-) )
Dean Smith ('73 RWA)

Dean. If you have a Marina based 1380, you will be using the Mini / midget size bearings anyway as you have to reduce the B/E size in order to 'stroke' the engine.

Make sure you use 'competition' spec or heavey duty bearings.

Mark.
Mark T. Boldry

Mark - I'm using Marina Block and the Marina Crank with a 73.5 mm bore.

My understanding was that I could choose to have the =1.75" marina big end journals offset ground to the 1.625" midget size to give a longer stroke and a 1430(ish) capacity. But this was choice rather than "have to" ?
Dean Smith ('73 RWA)

This thread was discussed between 15/09/2008 and 16/09/2008

MG Midget and Sprite Technical index

This thread is from the archive. The Live MG Midget and Sprite Technical BBS is active now.