hi i need some help please. i have a 572 with 440-1 heads 14.98 c.r. i am wondering what is a good plug heat range to use ? i have ngk -10s now suggested by the guy that did my heads . just wondering what others are using ? thanks

I would look at these
http://www.championsparkplugs.com/results_cross.asp?pid=C53CX&x=0&y=0
Indy says Champion
A 57 may be cold enough
http://www.championsparkplugs.com/results_cross.asp?pid=C57CX&x=58&y=16

Phone indy!

thank you Dodgem

which fuel, race gas, E85 or ?

i am running c14. with .92 jets

An NGK -10 is pretty cold.
No hotter than a -9, IMO.
So, keep an eye on them when running and adjust accordingly.
If you run the -10, tune the idle and pit driving to avoid loading them up too much.

Cross reference:

Quote:

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Other possible spark plugs:
NGK: R5671A-10
Autolite: AR3932
Champion: C57CX

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I run the Champion C59CX in mine,was told by Indy the 59 would be better than the 57 in my engine on alcohol. Next time I order I think I will get a set of each 57 & 59 to try.
I have not run the Autolite's yet but the cross over from the C59CX is AR3933.

thanks i will try the -9 ngk .

do you need to run a hotter plug with alcohol ?

Indy says the C59CX plug was the best for both alcohol and gas. I also had thought that with alcohol a colder plug would be best and I think I may just try it and see this year.I will only be out a couple of $$$ to put a set in and make a pass to see which is best. I have been having to order the plugs from Indy,but was told @ Advance they could order the plugs for me. Unlike most I don't have a problem with Indy but Advance is only a couple of miles up the road and no min. or shipping charges.

c59cx is a -9 in ngk thats what i going to try . i think the -10 ngk never get enough heat in them to get clean. thanks