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MG MGB Technical - Distributor position

Thanks to Jeff Schlemmer, I replaced my worn 25D with a rebuilt, recurved one with pertronix ignition. My 80 LE runs much better, but I have one question for the experts out there. In order to position the distributor consistent with the recommended advance, the vaccum hose is pushed right up against the oil pipe above the distributor. I just barely get it into range (about 12 degrees BTDC) and cannot rotate counterclockwise any further.

Someone has been inside the engine along the way (before I owned it) and I don't know the extent of work. My question is, would this indicate that the camshaft is not in proper alignment with the crankshaft? I should check it anyway, but thought I would ask the gurus here first.
Rick Penland

Rick. It most probably indicates that the distributor drive gear, which mates with the camshaft, is off very slightly and needs to be turned one tooth to the right (clockwise).

To do this requires removing the distributor, remove the distributor clamp, remove the single screw holding the distributor housing into the block,remove the distributor housing, use a 7/16" bolt (from memory) to remove the distributor drive, rotate the distributor drive one tooth to the right, reinstall the distributor drive, reinstall the distributor housing, reinstall the distributor clamp, then install and time the distributor.

Sounds more complex than it is to actually do.
But, the screw holding the distributor housing into the block can often be difficult to remove. Big screwdriver, preferably a blade in a socket, does the job.

Les Bengtson

Thanks, Les. I thought the distibutor drive had less teeth and would make more of a difference than that, but sure you know what you're talking about. It should be easy enough to do. I remember that screw you're talking about and it can be "boogered up" easily if you're impatient or don't have the right tools. Sometimes, a cold chisel with a small impact area, but not too small or too sharp a point will drive it out when applied correctly (from above and on the left while looking at the screw). I have an impact driver and liquid wrench so will try that if it's necessary. The distrubutor is working fine, but for fine tuning, would like a little more range than butting up to the oil pipe allows me.

I should check the alignment of the cam to the crankshaft at some point, but taking the easy way out for the time being.
Rick Penland

I'm glad to hear the distributor is working out for you. Make sure to report back any additional info you may have on Les's fix!
Jeff Schlemmer

I am pleased to hear that a rebuilt/recurved distributor is helpful - could you give advice on where one can be purchased with confidence in quality and accuracy of advance curve - can my old one be rebuilt and recurved properly..thanks
Jeff Delk

Jeff. John Twist, of University Motors Ltd., has been offering quality distributor rebuilds for many years now. As you note from the original post, our own Jeff Schlemmer is now offering such services also. Either of them should be able to assist you.

Les Bengtson

[now understand, Jeff is a friend of mine]

He can advertise, and get away wid it-------

But if I ad-- Amsoil, [synthetic oil] hoooeeeeey, do I get burned-----------

Even to tell the success stories.

Safety Faaaassssst
DCM McCullough

Dwight, I knew I was treading on thin ice with this! Its not really advertising if I display my email address is it?
My goal isn't to make money, or I'd have to charge a lot more. I'm just trying to be of assistance to those who suffer from some of the same problems we all do (eventually) with these cars.

By the way, thanks for the public kudos Rick!
Jeff Schlemmer

This thread was discussed between 21/06/2006 and 26/06/2006

MG MGB Technical index

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