Another "what plugs" question

What spark plugs should I use in my 547 when running NA?
P51 Heads
98 octane pump gas (in Australia)
39cc dish for around 10.2:1 compression

Thanks

ngk

Yeah.......Thanks.

How 'bout a part no. ?

Beast wrote:Yeah.......Thanks.

How 'bout a part no. ?

i run A460 heads so i'm not sure about a part# for p-51's. type "plugs" in that search box and you'll see lots of info,not be'n a smart ass,just sayen.

Yeah, I did that. Couldn't actually find what I was looking for. Lots on A heads and DOVEs. Nothing on the P51s.

Looked harder and found a bit of info.....

Re: Recommend a spark plug
richter69 on Wed Jan 26, 2011 10:41 am

.been using a AR3911 here
------------------------------------------------
This is using methanol but right?


Re: Recommend a spark plug
c.evans on Wed Jan 26, 2011 11:56 am

.Autolite #AR 3934 is used in just about all the racing engines around here.

Charlie Evans

------------------------------------------------
Still have a question about it but.... Those "racing engines" would have more comp than I'm running, and probably race gas too. I'm on regular pump gas, is the AR 3934 still going to be the right plug?

I was running AR3923 according to Lem on my SCJ motor, it was 13.0:1 compression. Pm him and see what he would recomend for ya.

the 3934's will be a little cold on a 10.5:1 street engine.

Beast wrote:What spark plugs should I use in my 547 when running NA?
P51 Heads
98 octane pump gas (in Australia)
39cc dish for around 10.2:1 compression

Thanks

At your 10.2/1 compression ... Autolite #3924
The 3911's will work fine, it is just a bit cold and will need to be replaced more often from low speed fouling.

Found this in another forum and thought it might be helpful.

http://www.autolite.com/sites/default/a/uploads/en/understandingheatrange.pdf

Thanks for the info guys.