Spark Plug gap

[NY_GN]

I've seen the other threads, but I put in new Autolite 23 plugs gapped at .32. Got some knock at 22# boost. All numbers on scanmaster look good TPS, IAC, fuel rises 1:1 with boost........

Should I attempt .28 gap with these plugs? Any expierence with these?

Gotta change my sig block, but I have a Precision 5858 on the car now; if that changes your opinion on the cause.

 

[Boost231]

Reduce boost would be my first step

 

[NY_GN]

Reduce boost would be my first step

That's a turn of a knob, step 2?

I'm just gonna re-gap the plugs and see what happens. I'm hoping to hear from people that used these plugs, but I guess the different set-ups will yield different results.

 

[Boost231]

What ignition system?

 

[rodruckus]

What type of fuel are you running? I run same plug and gap @22psi with 91/alky and sometimes C16. Never any knock on scanmaster even through my shifts.

 

[BuickMike]

Report back how that works out for you. I'm gapped at .032 with R42TS plugs and get knock in 3rd sometimes at WOT with pump gas / alky. I was more prevalent on hot days, but honestly seemed intermittent. AFR is rock solid so it is not a fueling issue. Then one day I pulled the timing back to 17 and it started breaking up at WOT on hot days. It was recommended that I tightened up the gap and try again. I still have not tried, but probably will Sunday night if I get a chance.

 

[NY_GN]

What type of fuel are you running? I run same plug and gap @22psi with 91/alky and sometimes C16. Never any knock on scanmaster even through my shifts.

93 pump gas.

 

[NY_GN]

Report back how that works out for you. I'm gapped at .032 with R42TS plugs and get knock in 3rd sometimes at WOT with pump gas / alky. I was more prevalent on hot days, but honestly seemed intermittent. AFR is rock solid so it is not a fueling issue. Then one day I pulled the timing back to 17 and it started breaking up at WOT on hot days. It was recommended that I tightened up the gap and try again. I still have not tried, but probably will Sunday night if I get a chance.

I'm gonna re-gap then report back, unless the Yankees lose, then I'm gonna drink the pain away and do it Sunday.

 

[rodruckus]

No way, not enough octane for that much boost. You need to crank it down to maybe 15ish and work up from there. You're going to grenade your engine if you don't. Look into getting an alky kit. You need better fuel to run boost like that.

 

[NY_GN]

Report back how that works out for you. I'm gapped at .032 with R42TS plugs and get knock in 3rd sometimes at WOT with pump gas / alky. I was more prevalent on hot days, but honestly seemed intermittent. AFR is rock solid so it is not a fueling issue. Then one day I pulled the timing back to 17 and it started breaking up at WOT on hot days. It was recommended that I tightened up the gap and try again. I still have not tried, but probably will Sunday night if I get a chance.

No way, not enough octane for that much boost. You need to crank it down to maybe 15ish and work up from there. You're going to grenade your engine if you don't. Look into getting an alky kit too. You need better fuel to run boost like that.

I got an alky kit, been running it for 4 years now.

Is that not showing in my profile? I had no issues running this much boost with the old plugs. I'll go back to them, but the idle is better with these autolites. O2s are better too, I'll make'em work just want a shortcut if possible.

 

[rodruckus]

[93 pump gas.[/QUOTE]

I'm confused, are you running alky, too? Unplug the wires on your coil pack and check for corrosion. I had to sand some off from the tip of one last year. How old's your coil pack? Have you considered testing it to see if it's faltering?

 

[NY_GN]

[93 pump gas.

I'm confused, are you running alky, too?[/QUOTE]
Yes!

 

[dynoman]

Is it the original alky pump ?? After 4 years you should check alky pump pressure . Razor makes a tester for his kits and it works great . Sam

 

[bison]

If you suspect an ignition problem close the gap down to about .020"


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[NY_GN]

Is it the original alky pump ?? After 4 years you should check alky pump pressure . Razor makes a tester for his kits and it works great . Sam

2nd pump.

 

[NY_GN]

If you suspect an ignition problem close the gap down to about .020"


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Really, not questioning logic, but that's extreme. Is that normal with this brand?

 

[bison]

The coil doesn't know what brand plugs you have. So it's irrelevant to a situation where the ignition strength is in question. Closing the gap to help the ignition is common. Top drag racers run even smaller gaps on some applications. They understand the importance of a spark and don't want l run a larger gap and risk a mis fire. There's no power in large gaps. There may be some gain in low rpm low cylinder pressure idle quality but we're not concerned with that if you are trying to pinpoint a possible weak ignition.


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[NY_GN]

The coil doesn't know what brand plugs you have. So it's irrelevant to a situation where the ignition strength is in question. Closing the gap to help the ignition is common. Top drag racers run even smaller gaps on some applications. They understand the importance of a spark and don't want l run a larger gap and risk a mis fire. There's no power in large gaps. There may be some gain in low rpm low cylinder pressure idle quality but we're not concerned with that if you are trying to pinpoint a possible weak ignition.


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Point taken.

 

[GNRick]

Bison if the smaller gap fixes the problem would you leave it alone or start shopping for a new module/coil?

 

[bison]

Bison if the smaller gap fixes the problem would you leave it alone or start shopping for a new module/coil?

First id verify primary voltage at the module and be sure my wires were up to the task. Then I'd view the spark at the coil and through the wires.


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