V8 Timing

Note how No.1 plug lead (red) is on the cap between the coil lead and the vacuum capsule. Note also how the lead for No.3 (yellow) is between the leads for Nos. 5 and 7 where they go through the comb on the rocker cover, i.e. they are not in numerical order 1, 3, 5 and 7 as one might expect. This is because 5 and 7 are adjacent in the firing order and if the leads run close together when 5 fires it can generate a small spark in 7, which can be enough to initiate combustion in 7 significantly before it is due i.e. way too far advanced. This image also shows how the leads for the even-numbered cylinders leave the cap at right-angles, whereas those for the odd-numbered cylinders are straight.

However I discovered my leads have been one position clockwise for a long time, which isn't as noticeable as it would be on the 4-cylinder. In this position with the engine turned to TDC on No.1 cylinder as shown by the crank pulley markings the tip of the rotor is directly over the bar between the vacuum capsule and the points plate, whereas it should be closer to the notch in the body (arrowed).

When withdrawn the screw of the drive gears has turned the rotor slightly anti-clockwise (the 'book' says 30 degrees, but mine only moves 25 degrees), and should be directly over the notch. Note that the V8 distributor turns clockwise with the engine running, not anti-clockwise as on the 4-cylinder engine.

This puts leads 1 and 8 either side of the front cap clip, instead of leads 4 and 8. Originally these MGOC silicone leads had all straight connectors at the cap end, which due to the tilt of the cap pressed the leads going to the even-numbered cylinders up against the bonnet which I wasn't happy with. I'd had no problems, but I took four right-angle connectors off an old set and the straight ends of the MGOC leads are a neat push-fit into those. Incidentally these leads have now done nearly 100k and 20 years!