MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

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 - Distributor insatllation

I rebuilt my distributor and need to reinstall. Is there a way to tell when #1 is at top dead center on the copression stroke without pulling the valve cover again? Hoe can I distinguish between TDC comression and exhaust? Thanks.
Dan Hiltz

Dan - Remove the #1 plug, but our thumb over the hole and turn the engine over until your thumb is pushed off the hole. At that point, #1 piston is coming up on TDC on the compression stroke. Cheers - Dave
David DuBois

Forgive me if you know this but it is possible to reassemble the distributor 180 degrees out. When doing as Dave advises, and when the piston is at the top of the cylinder, note where the rotor is pointing and that is No.1 plug, then count 1 3 4 2 anti-clockwise from there for the other plugs.

Note also that whilst it is only possible to fully engage the distributor drive dog to the drive gear in one position only, it is possible to partially engage it 180 degrees out again. Fully engaged the flange on the distributor body will be flush to the mounting plate, when the mounting plate is bolted down to the block. Partially engaged there will be a significant gap between the flange and the plate. This may allow the engine to turn the distributor when turning it my hand, but when you fire it up it will almost certainly slip.
Paul Hunt 2

If you only partially engage the dog, the distributor mounting plate won't bottom out against the block. When the dizzy is in right the vaccum advance unit will be pointing up at about 11:00 oclock.
Bruce Markle

OK, I'm at TDC on number 1 (meaning that the timing mark on the pulley is aligned with the topmost indicator on the block). The rotor is pointing at roughtly 1 o'clock and can't move, but the distributor body can rotate freely.

I have the port on the vacuum advance pointing straight up and it's at roughtly the 11 o'clock position.

Does the number 1 lead go on the cap closest to the 1 o'clock posiiton?

Thanks.

Dan
Dan Hiltz


Does the number 1 lead go on the cap closest to the 1 o'clock posiiton?

Yes
Steve Buchina

And remember that even thought hte crankshaft turns clockwise, the firing sequence is 1-3-4-2 with the distributor rotor turning counterclockwise!

Barry
BJ Quartermaine

This thread was discussed between 15/05/2007 and 21/05/2007

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now