When I converted my yblock to a Duraspark system I went with the plug gap that was used for that system. Mines set at .045. Hasn't missed a beat.

Dan      Kingman Az.      86409

Ted, that's really good information regarding plug gap with boosted applications. I'll keep that in mind when I re-tune my blower motor.

Rono

  Ron Lane,  Meridian, ID

i've got the same set up. i set mine at .040. runs fine. although my not very old blaster coil just went bad.

As a general rule, the 0.035” spark plug gap works with most ignition systems and carburetion.  Dyno testing in those circumstances finds no horsepower gains in increasing the spark plug gaps and can be counter productive when gaps are too large resulting in misfires in the higher rpm ranges.  With fuel injection and leaner mixtures, then a wider spark plug gap can be of benefit with a ‘hotter’ ignition.  As the compression ratio goes up or in ‘boosted’ applications where cylinder pressures are higher, then reducing the spark plug gap to numbers as low as 0.015”-0.020” can be necessary depending upon the ignition system.  Randy Gummelt’s blown Y dragster ran 0.020” spark plug gaps with 15 lbs. of boost in conjunction with a 7AL MSD ignition box.

Lorena, Texas (South of Waco)

Think Ted did some testing on this ? anyway standard plug gap is fine , I have similar and run at .038  no problem.



"Came too close to dying to stop living now!"

.035" will definitely work.  .040" will probably work with that hardware.  


Lawrenceville, GA

Checking and re-gapping the plugs in my 56 Customline with Blaster coil and Pertronix II Ignition. The plugs I've been running are Champion RF-11Y and it seems like I gapped them last at about .035" but I think they should be at least .040". I can't find any notes on this. Any opinions?

Thanks,

Rono

  Ron Lane,  Meridian, ID