Which plug

[bullerman]

What plug do you run in your clone? Down in Louisiana and it is getting hot. Thanks

 

[CarlsonMotorsports]

Autolite 3910X.

-----
Thanks and God bless,
Brian Carlson
Carlson Racing Engines
Vector Cutz
www.CarlsonMotorsports.com
Carlson Motorsports on Facebook
31 years of service to the karting industry
Linden, IN
765-339-4407
bcarlson@CarlsonMotorsports.com

 

[meracer9]

3910x

 

[racing promotor]

Whichever one my builder has in it, unless he tells me to change it.

 

[bullerman]

Need to order a couple in case I ever get to race. Thanks

 

[Renegade]

A few years ago I dynoed every 3/4" reach plug I could find. Some were good, some okay and some were pure junk. The AR3910X was better than the second best plug by 2 tenths. The second best plug was a Autolite 63.

 

[DynoDon]

Good to hear from ya Bennie

 

[1fasttiller]

Only bad thing about the 3910X is the cold heat range, it is a VERY cold plug and not ideal for restricted clones at all. We use a standard NGK extended tip in our restricted clone motors, they last twice as long and cost half of a 3910X

 

[alvin l nunley]

I pretty much have to believe what Carlson says, and having never raced a Briggs with that plug, or any Briggs for that matter, it sure makes me wonder.
First off, doesn't that extended tip
raise the compression of the engine? Isn't that illegal?
Second off, being down in the combustion chamber, doesn't that plug run awfully hot?
I can see that plug being a benefit to the engine when used for the purpose it was built, but in a racing situation, I can't help but wonder; "would a purpose built racing plug be better"?
In two cycle racing, with the Yamaha, if any part of the plug threads extended into the combustion chamber, it was illegal.
The innovator in me screams; "I want to go racing"!!

 

[OVALTECH1]

-7 NGK in the plate motor -8 NGK in the unrestricted.

 

[OVALTECH1]

if I have to use an Autolite I’d sooner shoot my own foot off but it’s the AR3935

 

[1fasttiller]

-7 NGK in the plate motor -8 NGK in the unrestricted.

Yes sir, we're using the -7 NGK's and love them.

 

[Bumpy]

In a gasoline Clone, I think you'll be happier with an extended nose plug vs the super cold 3910X.

 

[racinnut15xm]

A few years ago I dynoed every 3/4" reach plug I could find. Some were good, some okay and some were pure junk. The AR3910X was better than the second best plug by 2 tenths. The second best plug was a Autolite 63.

Open or restricted? What was the 2 worst?

 

[Renegade]

Open. I don't remember the worst. It was an aviation plug The surface gap marine plugs were not good. Even Tried splitfire and E3 nothing special. The 3910X was the plug for power but it does foul easy.

 

[BLACK DEATH]

I use an ngk bp7s something like that. No issues at all.

 

[Lewis27]

Yes sir, we're using the -7 NGK's and love them.

Do you use the stock gap or do you regap them?

 

[1fasttiller]

I usually use stock out of the box, which is around .035-.040 if I recall.

 

[OVALTECH1]

I leave em be as well they are the short strap plugs so unless they are crushed run em.

 

[Bmsracin32]

This the NGK 7 plug you use for plate motors ? Thanks