Hi all -

I was looking to check my 1978's spark gap and on the FSM it has 2 different plug gap values (one for Canada and one for America). Does one provide better performance than the other? I'm in Texas.

The spark plug spec'ed for Canada is a resistor plug, BR____ . So with resistor wires and resistor plugs they might have decided that the smaller gap is necessary to avoid misses. Weird that they doubled up on resistance, but that's what they show. Maybe Canada had sensitive electronics at the time.

If you're running non-resistor plugs I'd run the larger gap. Generally, larger gap is better for performance/economy. A more complete burn.

Edit - I see in your other thread that you're running resistor plugs, but it also looks like NGK resistor plug wires n the backgorund. You could switch to non-resistor plugs. Or wait unitl the next tune-up, to save the money.

Edited Saturday at 10:51 PM3 days by Zed Head

Gotcha, so for the moment, go with the canadian spec gap since I have a resistor plug or the USA spec anyway? Yep, they are ngk wires.

I'd just go with the Canada spec if your ignition system is factory stock. Assume that the Nissan engineers had a reason.

On the other hand though, you're also running projector tip plugs. Many people do, but I don't think that anyone has actually shown a difference. The "P" plug was used in the 80-83 280ZX engines.

7 hours ago, Zed Head said:

I'd just go with the Canada spec if your ignition system is factory stock. Assume that the Nissan engineers had a reason.

On the other hand though, you're also running projector tip plugs. Many people do, but I don't think that anyone has actually shown a difference. The "P" plug was used in the 80-83 280ZX engines.

I believe I originally gapped these to the USA spec. Would dropping them down to the Canadian spec have me lose power but gain a smoother idle? Basically just curious what differences I should notice.

EDIT: I forgot to bring up that the PO installed a "Jacobs Electronics" spark box in the car. Should I still go with the canadian gap with my resistor plugs?

Edited Sunday at 03:29 PM2 days by chaseincats