MGB Register Forum

Bit of an odd request, but does anyone have a drawing, sketch/dimensions of the cam chain cover? I have a spare and planning to reverse engineer it, so I can machine a new one , but if anyone has a drawing, it will save me a good bit of time, thanks.

I've had a reply back from BMH, they do not have a drawing for this part. I've drawn what I can, it's accurate but in metric not imperial, but I've no idea what/where the datum is, guess it doesn't matter too much, it's just a bit messy. First job is to 3d print a space model, then get it CNC'd.

Just curious - if you have a spare one why do you need to make one?

Ian F

Hi Ian,
Good question, the one on the car at the moment is in very good condition but it is also fitted with a bracket that holds a 'crankshaft position sensor', it all works fine, but the OEM cover was never intended to be structural. I've got a second one , but it was only ever a spare, it's cleaned up, but was a but rusty. So the plan is to make a new one from a aluminium billet, it will be more rigid, for the sensor and obviously won't leak oil! I also was thinking of mounting a cam sensor on it too, at the moment the fuel injection is SPI, but with the cam phase, I can move to MPI. Just need to figure out how to get the cam phase....

Thanks for that info. Clearly an MGB far removed from my own!!

Ian F

Are you using a Megasquirt to control the ignition and fuel injection, a specialist ECU or an ECU from a donor vehicle ?

I got as far as installing a Megajolt on a Pinto engine I had in a kit car a few years ago and would be interested in doing something for both spark and fuel on the MGB if it were affordable.

Hi,

"Megasquirt" is a mere calculator!

I'm using a special ECU specifically designed for the B Series engine, it has seperate 3D maps for cylinder 1&4 and 2&3, due to the simeased inlets , seperate timing/maps for crank, idle and retarding during braking as well as shutting off the injection to save fuel.

The two main points are the engine is completely 'still' at idle, absolutely no vibration and the mpg is getting to 34-36, it should get better as the system 'learns', there are no 'knock' sensors, but the ECU monitors the rate of chage of acceleration (double differential) and can calculate (infer) drag, bhp and rolling resistance...a sort of a true rolling road.

To answer your question, it is not cheep, I doubt the money spent will be recovered, but it is the engineering challenge for me..