Oh no, another coil thread. More ohms???

[warefuller]

Point gap effect on coil heating

I understand that the Moyer electronic ignition has the dwell fixed at 55 degrees so the following won't apply. But with a points-and-condenser system, if you decrease the point gap, the dwell is longer, which will cause current to flow through the coil for a longer time (the dwell time), which results in a higher average power in the coil.

An aside: many old distributors have worn lobes which require a smaller point gap to give the same dwell. This is OK, since DWELL IS WHAT MATTERS, not the absolute value of the point gap.

Btw, a 55 degree dwell is larger than is common with most engines, but a shorter dwell is necessary with more cylinders and higher RPM. The Moyer electronic system, I understand, works well for many, many people.

[hanleyclifford]

I understand that the Moyer electronic ignition has the dwell fixed at 55 degrees so the following won't apply. But with a points-and-condenser system, if you decrease the point gap, the dwell is longer, which will cause current to flow through the coil for a longer time (the dwell time), which results in a higher average power in the coil.

An aside: many old distributors have worn lobes which require a smaller point gap to give the same dwell. This is OK, since DWELL IS WHAT MATTERS, not the absolute value of the point gap.

Btw, a 55 degree dwell is larger than is common with most engines, but a shorter dwell is necessary with more cylinders and higher RPM. The Moyer electronic system, I understand, works well for many, many people.

Hear, hear - I installed the Moyer EI a few years ago and I haven't had to take the distributer cap off since, nor have I changed the cap and rotor for as many years.

[sastanley]

Hanley, I installed EI in 2009. I also had not needed to remove the cap until this past weekend. The advance weights were frozen after 6 seasons. The engine ran for 3 hours and stumbled like the old coil killing days. Freed up the weights and it ran for 9+ hours the next day!

Just one more possibility for everyone to look at. I have a post floating around about this in the electrical section just as a reminder to all of us EI people! I think if you remove the cap & rotor, you should be able to grip the distributor shaft by hand and rotate it a few degrees against the weights to confirm they are free..mine were not!

[hanleyclifford]

Hanley, I installed EI in 2009. I also had not needed to remove the cap until this past weekend. The advance weights were frozen after 6 seasons. The engine ran for 3 hours and stumbled like the old coil killing days. Freed up the weights and it ran for 9+ hours the next day!

Just one more possibility for everyone to look at. I have a post floating around about this in the electrical section just as a reminder to all of us EI people! I think if you remove the cap & rotor, you should be able to grip the distributor shaft by hand and rotate it a few degrees against the weights to confirm they are free..mine were not!

Actually, I lied. Last year when I took the engine apart for inspection I took the distributor apart and oiled the weights.

[krazzz]

I think if you remove the cap & rotor, you should be able to grip the distributor shaft by hand and rotate it a few degrees against the weights to confirm they are free..mine were not!

Great advice and something worth looking into.