Spark plug recomendation

Hey guys,

I have a 533, 13:1 compression bbf with mechanical injected alcohol and no power adders. It's used in drag racing. My engine builder put NGK vpower 9's in it and if I understand correctly, that is a "cold" plug. I would like to switch over to Autolite racing plugs. Can someone give me a part number to start with please?

Thanks
Alan

HorsinAround wrote:Hey guys,

I have a 533, 13:1 compression bbf with mechanical injected alcohol and no power adders. It's used in drag racing. My engine builder put NGK vpower 9's in it and if I understand correctly, that is a "cold" plug. I would like to switch over to Autolite racing plugs. Can someone give me a part number to start with please?

Thanks
Alan

Has the engine got domed pistons or flat-tops ...?
What heads ...?

rmcomprandy wrote:

HorsinAround wrote:Hey guys,

I have a 533, 13:1 compression bbf with mechanical injected alcohol and no power adders. It's used in drag racing. My engine builder put NGK vpower 9's in it and if I understand correctly, that is a "cold" plug. I would like to switch over to Autolite racing plugs. Can someone give me a part number to start with please?

Thanks
Alan

Has the engine got domed pistons or flat-tops ...?
What heads ...?

Sorry for the lack of details. Flat top Diamonds, AFR 315's.

HorsinAround wrote:

rmcomprandy wrote:

HorsinAround wrote:Hey guys,

I have a 533, 13:1 compression bbf with mechanical injected alcohol and no power adders. It's used in drag racing. My engine builder put NGK vpower 9's in it and if I understand correctly, that is a "cold" plug. I would like to switch over to Autolite racing plugs. Can someone give me a part number to start with please?

Thanks
Alan

Has the engine got domed pistons or flat-tops ...?
What heads ...?

Sorry for the lack of details. Flat top Diamonds, AFR 315's.

Probably Autolite 3911 ... or AR3911.

rmcomprandy wrote:

HorsinAround wrote:

rmcomprandy wrote:

HorsinAround wrote:Hey guys,

I have a 533, 13:1 compression bbf with mechanical injected alcohol and no power adders. It's used in drag racing. My engine builder put NGK vpower 9's in it and if I understand correctly, that is a "cold" plug. I would like to switch over to Autolite racing plugs. Can someone give me a part number to start with please?

Thanks
Alan

Has the engine got domed pistons or flat-tops ...?
What heads ...?

Sorry for the lack of details. Flat top Diamonds, AFR 315's.

Probably Autolite 3911 ... or AR3911.

Thanks Randy

AR 3911 is what i ran before i added the gas primer system to the rons injection. 11’s foul rather quickly on gas so i switched to 24’s or 26’s. If all you do is start it on gas 11’s will be fine but if you run it for any length if time to build heat or flush/lube the cylinders after a day at the track they will foul.

stanger68 wrote:AR 3911 is what i ran before i added the gas primer system to the rons injection. 11’s foul rather quickly on gas so i switched to 24’s or 26’s. If all you do is start it on gas 11’s will be fine but if you run it for any length if time to build heat or flush/lube the cylinders after a day at the track they will foul.

Yea, I use the gas primer system to start it, then pull the lean out/fuel shutoff and run the primer for a minute or so. THen at the end of the day I turn it on and shut the alky off. Looking at the Autolite cross reference chart, I don't see a 3926. I do see the AR3924 though.

Try both. I may be doing something else wrong. There has definitely been a learning curve on running the primer plus system. Its a work in progress. I run mine on gas in staging lanes sometimes too. i think the 26’s may only come in standard autolite.

stanger68 wrote:Try both. I may be doing something else wrong. There has definitely been a learning curve on running the primer plus system. Its a work in progress.  I run mine on gas in staging lanes sometimes too. i think the 26’s may only come in standard autolite.

I have a set of 3911's on order and will get a set of 24's coming as well. I also found a full set of v power -8's in my tool box that I don't remember buying ( ) So I will have an assortment to experiment with.

What ignition are you running with your Rons FI setup? I upgraded to a 7al-3 over the winter and recently had an 8 offered to me. Not sure if the 8 is worth the money considering the extra's that I'll have to get with it.

HorsinAround wrote:

stanger68 wrote:Try both. I may be doing something else wrong. There has definitely been a learning curve on running the primer plus system. Its a work in progress.  I run mine on gas in staging lanes sometimes too. i think the 26’s may only come in standard autolite.

I have a set of 3911's on order and will get a set of 24's coming as well. I also found a full set of v power -8's in my tool box that I don't remember buying ( ) So I will have an assortment to experiment with.

What ignition are you running with your Rons FI setup? I upgraded to a 7al-3 over the winter and recently had an 8 offered to me. Not sure if the 8 is worth the money considering the extra's that I'll have to get with it.

The plugs you mention are all different heat ranges ... all on the cold side but, some are colder.

7al2 , hvc2 coil, crank trigger with grid controller.