Spark Plugs

[Schurkey]

I learned that when I was adapting GM 4 pin HEI modules and two pin coils to my 82 Yamaha XJ1100. It took me a bit to wrap my head around it.

How did that work out for you?

I've got some parts (wire harness, two waste-spark HEI coils, two modules) to adapt a pair of 4-pin HEI modules to an '83 Honda CB1100F. Never completed the project. There was extensive discussion on a Honda CB forum on how to make that work. Takes some real trickery to get the engine to start due to the module being set up to expect minimum 4 cylinders firing (four module triggers) in 720 degrees of crank rotation (and more-commonly 8 cylinders/720) versus two module triggers in 720 degrees--the module shut-down from lack of activity.

And then there's the shape of the Honda pickup coil reluctor tooth vs. GM HEI pickup coil reluctor teeth. Doesn't provide the module with the waveform it's expecting.

Maybe PM me to not derail this thread even more...please.

 

[0xDEADBEEF]

Holdener tested them

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[L31MaxExpress]

Holdener tested them

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I put the used cheap AC Delco copper plugs back in my 383 while I had it torn apart. Without worrying at all about it.

I had previously pulled the E3s out to put a colder plug in.

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[0xDEADBEEF]

I put the used cheap AC Delco copper plugs back in my 383 while I had it torn apart. Without worrying at all about it.

I had previously pulled the E3s out to put a colder plug in.

You must be registered for see images attach

I'm an NGK guy just because I can figure out the heat range easily.

 

[Erik the Awful]

Any time a plug manufacturer advertises their multi-prong spark plug as more fuel efficient or more powerful, I permanently put that brand on my "scam" list. I was afraid I might have to put NGK on that list, but fortunately it looks like they only advertise their "Laser Platinum" plugs as being longer-lasting.

RX-7s did use a special multi-prong plug, but it was because they ate the electrode, and with four electrodes they lasted significantly longer. Then some doofus decided to advertise them to regular piston guys, saying they were a special "power" plug. Ugh.

 

[L31MaxExpress]

One thing from Holdeners testing not exactly straight across to these trucks unless LS swapped. Coil per cylinder ignition has much more spark voltage and energy than a single coil with a distributor. I have personally witness gains of 10-20 hp converting LT1s and L31s to 24x CNP setups.

 

[0xDEADBEEF]

Unless you are racing in a spec class, there just isn't that much to be gained from plugs. Here's the indexing vid.

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[Erik the Awful]

I first heard about indexing thirty years ago when I was a vo-tech student. I'm wondering if the old single coil distributor ignitions systems had something to gain, but the newer high-power distributorless ignitions overpower the limitation that made indexing "important"?

Or was it always just wishful thinking?

Maybe somebody went to an engine builder and tried to pry his secrets out of him, so he invented this to throw them off.

 

[454cid]

RX-7s did use a special multi-prong plug, but it was because they ate the electrode, and with four electrodes they lasted significantly longer. Then some doofus decided to advertise them to regular piston guys, saying they were a special "power" plug. Ugh.

My Volvos 850 came with a weird multi-prong plug. I replaced them with a normal NGK, but I may go back to the wierdo style since they are OEM.