Spark plugs- ground strap”tech”?

[jake197000]

correct heat range is probably the most important thing.some two strokes use surface gap plugs but thats because the piston comes up so high theres no room.

[Caprimaniac]

Haha The best thing I have done is grind the strap away from the center electrode to the gap you want.

Yo... what difference from bending the strap to get correct gap?

[plovett]

I met a guy at Norwalk that sold spark plugs to the drag racers which he had modified. He would radius the edges of the ground strap and I think he may have even polished it. Seemed like he had a good following. See any value in that?

I think the value would be reducing hot spots and reducing the chances of pre-ignition.

I tried rounding off my electrodes once because I was worried about that. I don't have any quantifiable data, but the engine ran worse. It seemed like it had a slight miss at certain rpms and loads, and I felt like it made less power. I put in new unmodified plugs and have never looked back.

JMO,

paulie

[Dave Koehler]

I just want to watch someone drilling multiple .020 holes on a non flat piece of metal.
Would a slot be more beneficial?

Wondering:
Which makes for more ground breaking discussions? Spark plugs or oil?

[NewbVetteGuy]

I met a guy at Norwalk that sold spark plugs to the drag racers which he had modified. He would radius the edges of the ground strap and I think he may have even polished it. Seemed like he had a good following. See any value in that?

I think the value would be reducing hot spots and reducing the chances of pre-ignition.

I tried rounding off my electrodes once because I was worried about that. I don't have any quantifiable data, but the engine ran worse. It seemed like it had a slight miss at certain rpms and loads, and I felt like it made less power. I put in new unmodified plugs and have never looked back.

JMO,

paulie

IMHO, the downsides of a rounded electrode is that it requires more voltage to jump the same gap. I’d rather use any excess voltage capacity for a larger gap.


My guess is that your spark gap was already on the edge for your ignition system voltage at that RPM, cylinder pressure, temp, and AFR before rounding the electrodes and rounding them bumped the voltage requirement beyond what your ignition system could handle at those pressures/ rpm points.


I’ve been following a lot of people playing with some VERY high energy plasma systems the past few weeks and it’s interesting seeing them struggle with the exact opposite problems of traditional ignition systems. (Wearing our plugs SUPER fast even with Tungsten center electrodes and such high voltages and spark gaps that sparks jump in places where they’re not supposed to; looking at domed center electrodes and strapless plug designs to increase longevity as spark gap limitations are not a problem in that space....)


Adam

[af2]

Haha The best thing I have done is grind the strap away from the center electrode to the gap you want.

Yo... what difference from bending the strap to get correct gap?

The strap would be to the side of the center electrode not over it.

[chasracer]

I have always wondered why people pay so much attention to the spark plugs to start with - that's at a minimum the second gap that the electrical energy has to jump. The gap between the rotor and cap (conventional ignition) seems to me a place where some minor gains could be made. If you take a spare cap and do some cutting on it and then watch what the multiple spark boxes do plus watch what happens when you lead the rotor to cap tip timing, there's quite a bit going on. I am now setting up to have the leading edge of the rotor tip lined up with the leading edge of the cap. I believe this allows the rotor tip to put electrical energy across the cap tip for micro seconds longer and it certainly doesn't hurt anything. With the multiple spark boxes, the lower rpm range is much cleaner and I can stage the car more consistently. On the plugs I subscribe to the theory that electrical energy really prefers sharp edges and grind both center and ground electrodes to a nice point.

[peejay]

I just want to watch someone drilling multiple .020 holes on a non flat piece of metal.
Would a slot be more beneficial?

Wondering:
Which makes for more ground breaking discussions? Spark plugs or oil?

That depends. Are we talking about crappy plugs and crappy oil, or are we talking about Rapidfire V-tipped spark plugs, and Slick 50?

[Geoff2]

While the rotor gap is in the play, the spark plug tip is where the action is....

When Bosch released their plugs with 4 grd straps, & being ever the experimenter, I decided to try them in my 455 Pontiac. Trusty old NGK BP5S plugs removed, Bs installed. Immediately got surging at about 35-40 mph cruising. WTF? Refitted NGKs, no surging. I cut off the 2 opposite grd straps on the Bosch plugs, refitted, & could not feel any surging. Because I could not feel any surging, I was not convinced that was not some misfiring going on. So I refitted the NGKs. Surging is misfiring. No idea why the Bosch plugs did it, same heat range as NGK.

[Dave Koehler]

While the rotor gap is in the play, the spark plug tip is where the action is....

When Bosch released their plugs with 4 grd straps, & being ever the experimenter, I decided to try them in my 455 Pontiac. Trusty old NGK BP5S plugs removed, Bs installed. Immediately got surging at about 35-40 mph cruising. WTF? Refitted NGKs, no surging. I cut off the 2 opposite grd straps on the Bosch plugs, refitted, & could not feel any surging. Because I could not feel any surging, I was not convinced that was not some misfiring going on. So I refitted the NGKs. Surging is misfiring. No idea why the Bosch plugs did it, same heat range as NGK.

Were they made for something with more spark energy than you had perhaps?

[Circlotron]

I’ve been following a lot of people playing with some VERY high energy plasma systems the past few weeks and it’s interesting seeing them struggle with the exact opposite problems of traditional ignition systems. (Wearing our plugs SUPER fast even with Tungsten center electrodes and such high voltages and spark gaps that sparks jump in places where they’re not supposed to; looking at domed center electrodes and strapless plug designs to increase longevity as spark gap limitations are not a problem in that space....)

On some forum? If so, could you provide a link?

[chevyfreak]

While the rotor gap is in the play, the spark plug tip is where the action is....

When Bosch released their plugs with 4 grd straps, & being ever the experimenter, I decided to try them in my 455 Pontiac. Trusty old NGK BP5S plugs removed, Bs installed. Immediately got surging at about 35-40 mph cruising. WTF? Refitted NGKs, no surging. I cut off the 2 opposite grd straps on the Bosch plugs, refitted, & could not feel any surging. Because I could not feel any surging, I was not convinced that was not some misfiring going on. So I refitted the NGKs. Surging is misfiring. No idea why the Bosch plugs did it, same heat range as NGK.

I had the same thing, only it was with a chevy 153.
Old worn plugs ran better, someone told me my comp ratio were to low and another said the spark is not flaring out away from the plug and not giving a proper burn. Either way i never pursued a proper reason what happened. Just went back to what i know worked.
Even tried a tbi mod to it way back then(like 20yrs back). And canned the whole thing a couple hours later. I just like carbs.
I leave the "new tech" to the later model cars.
Im old school anyway, as is all my cars.hehe.

Chevyfreak.

[Geoff2]

Dave K.
I was using GM HEI with the MSD 7.5 amp module. I see many people dismiss any new type of spark plug as a 'gimmick'. Maybe. Maybe not.
When the projected nose core plugs arrived in the 60s, I'll bet many called them a gimmick. Now their use is just about universal with NA production cars.

[Jeff Lee]

I have always wondered why people pay so much attention to the spark plugs to start with - that's at a minimum the second gap that the electrical energy has to jump. The gap between the rotor and cap (conventional ignition) seems to me a place where some minor gains could be made. If you take a spare cap and do some cutting on it and then watch what the multiple spark boxes do plus watch what happens when you lead the rotor to cap tip timing, there's quite a bit going on. I am now setting up to have the leading edge of the rotor tip lined up with the leading edge of the cap. I believe this allows the rotor tip to put electrical energy across the cap tip for micro seconds longer and it certainly doesn't hurt anything. With the multiple spark boxes, the lower rpm range is much cleaner and I can stage the car more consistently. On the plugs I subscribe to the theory that electrical energy really prefers sharp edges and grind both center and ground electrodes to a nice point.

I set the vertical clearance of the distributer shaft to around .005”. I then cut a cap and measure the vertical distance from the tip of the rotor to the contact point of the cap. I then build up the tip of the rotor with silver solder and file that down to the clearance I want, around .020”. You’ll find the starting clearance is really wide. Maybe .075” or more? I also narrow the width of the rotor tip.

[Caprimaniac]

Haha The best thing I have done is grind the strap away from the center electrode to the gap you want.

Yo... what difference from bending the strap to get correct gap?

The strap would be to the side of the center electrode not over it.

Sorry, misread what you said ... "away"... Seen any difference on a 4- stroke? Maybe more Foul- proof there too, in case you run a Rich cylinder or two?

Have read and watched on the "plasma" ignition, but never seen any of the high- end Builders use anything but the old trustworthy. I'll sit on the fence using the trad NGK's until someone shows up With proof of something: simpler to use, more reliable & better output Hp- wise.