Which plugs?

[crateracer16]

I have a 418 with alum dome piston. Brodix 10x heads alum heads. .588 roller cam(both exh and int) Msd ign with 6al box. Running gas. Which spark plug would work good? Thanks.

[perfconn]

NGK R5671a-8

[sj valley dave]

totally agree with Perfconn...we run NGK 5671-8 or 5671-9 depending upon...Much less money than Autolites and seem to live longer!

[perfconn]

1/2 the price of Autolit or Champion racing plugs and twice as good.

[crateracer16]

Ok. Hard to find but luckily summit had them. How about a gap suggestion? Thanks for the help!!!!

[DANNY]

Hey Dave, how would that apply to what i run cus I im not likin them AR133's lol

[perfconn]

Gap them on. 040 if you use MSD ignition.

[Dirtrunner35]

Napa can get them

[joedoozer]

Yeah I have been running AR133 and 134's. Got a new carb and thought about trying the NGK 5673-8's. Should I stick with the Autolites or give the NGK's a try?

[perfconn]

Your choice. Spend more money for the Autolites or save money and get just as good performance for less money.

[crateracer16]

Ok. Thanks!!!!

[Racer Roy]

To continue this topic... I have been using NGK B7S's for years in my 462's with no problems at all.
Now I am switching to Bowtie heads (14011034) and I notice they are a tapered seat plug. What is the NGK number for this application?

Thanks guys

RR

[sj valley dave]

You can get NGK's at NAPA or O'Reilly's etc..almost anywhere..Danny, the crossover number for an AR-133 is a NGK-R5673-8...One of the problems with NGK is that bike shops know what a NGK B8-EV plug is...but our good old NAPA/Autozone/O'Reilley needs the order code.. NGK-5671A-8 is order code 4554...Danny, the order code you need for NGK-5673-8 is 3249..

[DANNY]

Terry, I run DUI setup good ole HEI... What should the gap be on both the 133's and the NGK? I been gapping my stuff at .045 forever?
Thanks Dave! Lol im gonna walk across the street on lunch to o'reillys today and just hold onto the spare set of 133's I have save em in case I get in a pinch lol

[perfconn]

.045 is good on the HEI but you can go up to. 060

[DANNY]

Oh wow ok maybe ill open it a lil more say 50-55

[perfconn]

Bigger the gap the harder it is on coils.If. 045 works then keep on keeping on.

[merc123]

I was searching around for spark plugs. Last year I used AR 134's in my motor, they lasted two races until they began to misfire. Changed them out to Denso plugs and ran rest of the season with no problems. I switched back to the 134's this season just to see if I got a bad batch. I ran the practice session (5 laps) last week with no issues. Went to hot lap this past weekend and it misfired at 5800 RPM. Changed the plugs for heat race and had 0 issues out of the 134's.

I'm getting ready to switch over to the NGK's and throwing out the 134's. I spoke with Vic Hill about them at the track and he said they used to be a really good plug but he has started having lots of trouble out of them.