Autolite "X" plugs Letting the cat out of the bag.

Ok from what I understand
If you run this plug don't idle for too long or you risk fouling out or wetting the plug with fuel
When your motor is cold this plug isn't that good but when at racing temp this plug is amazing
 

"J'-remy

Member
Ok from what I understand
If you run this plug don't idle for too long or you risk fouling out or wetting the plug with fuel
When your motor is cold this plug isn't that good but when at racing temp this plug is amazing
correct i believe the builders open up the pilot jet to get more fuel at midrange but it creates an overly rich idle
 

"J'-remy

Member
I bought some AR3932x plugs to try out and see how they do. Just want to try some testing out. I will use them in my predator but will use the 3910 plugs in the other one.
 

OVALTECH1

Site Supporter
The AR3935 would be the better plug in a plate ap. for sure. We run the NGK fine wire iridium in our plates. Excellent non foul properties.
 

"J'-remy

Member
looking on the internet and cross referencing for the past 30 min
1. can't find a Autolite 3922 22x nothing cross-referencing says go fish doesn't exist
33 and the 10 net the same heat range ngk 9 and champion 59 in one instance between two plugs one was listed medium hot and the other medium cold with the 33 being hotter but barely
there is a 3932x but it is colder than the 3910x
Numbers don't mean diddly
 
Here in the Midwest early spring and into the fall I change from the 3910x to the NGK R5672A-8. The R5672A-9 is comparable to the 3910x so running the 8 is the next step to a hotter plug….

Others may not believe it or to them it may not matter…… but it does…..
 
from what I was told the trick with the 3910x is that it stuck down into the hole and upped the compression compared to a conventional plug.
Yep. In predators I took washer off and the cht lead off aswell and put plug as far down in motor as I could. Never hit piston.
 
Top