Welcome to our resource for MG Car Information.



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 - crankshaft pulleys

I'm looking at getting a 2 belt pulley so I can fit a Judson supercharger, does anyone know if a sprite midget one fits, are there any 3 belt pulleys for aircon as well or could this overload it, and any sources?
Thanks so much, Patrick
ph healey

T A.C. systems that I have seen have the compressor driven off the water pump pulley. Not a good idea for supercharging. Ray '67 MGB Moss SC

Driving an A/C compressor off the water pump pulley is a bad idea. Sufficient tension to keep the compressor turning will tear up the H2O pump. ' Been there, ' done that. I'm fixing it now.

The crankshaft pulley is also the harmonic balancer, and anything that alters its mass is also, potentially a bad idea. No doubt Steve S. from Virginia will weigh in on this, explaining the harmonic balancer function much better than I can. Based on what he has written in the past, I would be cautious about doing this.

Allen Bachelder

modern belt drives (flat belts)won't work with the existing pulleys. You would need at best 2 V type belts and high tension. There is a large load also on the front main bearing. Some manufacurers use a heavier duty bearing shell for the top side of the front main bearing.
Barry Parkinson

Thanks guys
Still seems that at least a double pulley on the crank is how they supercharge, and do away with the harmonic balancer. So much for superchargers not taxing the crank.
Anyone know the diameter of the standard pulley and its shaft, I dont have a car yet!
Is the pulley exclusive to a B? Does a sprite or mini fit< or other autins etc?
Thanks again
ph healey

There are at least two ways to go. The original Judson setup used the stamped crankshaft pulley (MGA, early MGB type)and a second aluminum 2 groove pulley was installed over the end of the existing pully and a new, longer bolt used to secure the pulley sandwich. It is also possible to use the later style harmonic balancer setup with a custom deging pulley. Both types are available from George Folchi, who is the recognized Judson rebuild expert stateside (use a search engine to find his contact information).

Steve Brandt

This thread was discussed between 15/03/2007 and 24/03/2007

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.