Which Plugs?

[trink408]

I'm looking for some suggestion on what plugs to use when I start tuning my motor with Nitrous. I plan on running about 3oohp worth of spray on my motor, and I'm not sure what heat range I need to be safe.

I'm looking for something in the autolite line of plugs, someone suggested AR 3933, but I'm not sure if that is a good heat range.

Some details about my combo:

408 Windsor
11:5:1
Flat Top Pistons
Victor JR heads
34 degrees total timing--plan on pulling out around 16 degrees for 300hp shot.
C-16 gas for the nitrous fuel system.


Any Thoughts????

[Chuck]

Here is what nitrous guy D Bandt sent me, about the same motor except I have a little more compression.

"Go two ranges colder and start with a gap of 0.035". If you're running the gasket type plug an NGK -9 or Autolite AR3933 would work well for you. You can probably even get away with a -8 or 3934....but i'd start cold and then go hotter."

Hope this helps!

[BBATCO1]

Those ngk-9s are the ticket

[trink408]

BBACTO1

What model of the NGK-9's do you use?

Projected tip, or non-projected tip?

[BBATCO1]

Projected on motor non on spray...

[trink408]

Projected on motor non on spray...

Just curious as to why that would be???? I'm trying to learn as much about this stuff as possible.

Thank You

[swilldup]

on a spray motor the projected tip acts as a big torch sticking out....i would use the r5671a-10....i guess you could prob use a -9...but 300 is a pretty good shot..

[BBATCO1]

on a spray motor the projected tip acts as a big torch sticking out....i would use the r5671a-10....i guess you could prob use a -9...but 300 is a pretty good shot..


Thats the stuff.......

[trink408]

Thanks a lot guys, I'm trying to play this game as safe as possible :thud:

I'm going to buy some ngk-9s and -10s.


What gap do you recommend as a starting point?

[BBATCO1]

32 to 35

[dave bandt]

I like the Autolite series better myself....but they are a little more expensive. Either will work, though.