The 'E' Type Forum

The plastic HT lead trunking had become hard and shortened, coupled with this the 'factory fit' section was showing a clamp fitted to the front of the head to support the HT leads on their way to the distributor cap.

Having purchased the above items I soon realised that the existing leads would now be too short to route through the new trunking and clamp. I rang the distributor doctor to supply me with his best HT lead and in the end also ordered on his advice NGK plug caps with cap boots (for both ends) and to top it off some numbered bands to make it easier to identify both ends are correctly positioned - for when pushing the HT's through the trunking it can be easy to make a mistake in cutting to incorrect length/wrong positions etc. Also on his advice to solder the HT ends to the copper discs.

One of those nice jobs to do on a lazy Saturday, not too taxing, but nice to get right (after printing off various reference on how to route the HT within the V of the head). I also found a poor connection from the CB side of the coil and therefore fitted a new end and after a few hours careful work stood back in admiration and ready to get the car on the ramp and do a final check on the timing with a strobe and finally set the carbs with knowing the electrical side was all in good shape.

What should have been a late afternoon run was swiftly halted - car would not start! (usually starts readily) anyway to cut a long story short (that saw it getting dark before I figured out how to ensure she would fire up)! it turns out that whoever set this up previously ran the numbers on the cylinder head counting the 'coil end' of the cylinder head as no 1 and not as it should be no 6. After swapping all the leads around on the distributor cap - some now too long, some now too short messing up all my careful cutting she fired up!

If you are still awake dear reader! would I be correct in thinking the distributor drive gear could be incorrectly positioned on the crankshaft - but don't see how due to the key way position? (although I think not because with the distributor in the correct position (to the manual i.e. vacuum end toward rear of engine) the rotor arm is pointing toward no 1 also as shown in the manual) so how come the firing order is in reverse?

To get the engine started the HT leads are now fitted to the distributor cap positions as follows: 1 and is now 6, 5 is now 2, 3 is now 4 and 6 is now 1 - how can this be? it feels as though it must be some kind of incorrect assembly of gears in the engine itself?

Richard

No1 cylinder is the one next to the bulkhead and no6 is closest to the radiator. So if your numbering was initially the opposite way round then to get the leads correct no6 would have to go to no1, no5 to no2 and so on. So what you've done is correct and the distributor will also be correct.

Alan

Hi Richard....you have it running so you now have them in the right order.....not what you want to here but i think your trying to blame the PO for cutting your leads too short....we have all done it.....just keep enjoying it...we have a great hobby and great cars to play with

This seems to cause perennial problems . It is a shame that Jaguar numbered the cylinders from the back, but it actually makes no difference at all which way you number them - the firing order is just the same. If the leads you now have are too long at the front and too short at the back, just swap them all over ( 1 for 6, 5 for 2 etc) and treat your engine as numbered from the front. This may not please the purists but it is in fact far less likely to result in confusion

Thanks gents for your replies but would as a matter of interest like to get my head around why its back to front? I don't for one minute think that cars left the factory with some firing 1 to 6 and others 6 to 1 something is odd...

Hi Richard...the engine will always fire in a rotating sequence of 1 5 3 6 2 4 it can never fire in reverse as you suggest above....it always fires on the compression stroke so when 1 is fireing the next to come up to fire is 5
If 6 was fireing the next to come up is 2 ....in reverse you would be trying to fire 3

Hi,
I had read an explanation for the 1 near the gearbox and the 6 near the radiator.
Jaguar employed engineers from the RAF and they put the number 1 like on a plane, concidering the gearbox as the propeller.
I don't know if it's a legend but it could be an explanation.
Mich