I just saw this video claiming that “side gapping” the spark plugs makes the spark much better and thus the engine run better. I’ve been around cars a long time and not heard of this. Is this real or nonsense?
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Works best when combined with an intake vortex generator ...

At first blush I thought “side gapping” was a new kind of Kama Sutra position to get more spark…..

Also works great to shorten spark plug life by forcing all electrode errosion to a much smaller portion of the electrode.

On the plus side, now that the compression stroke has a much better chance to blow out the spark, you'll get about the same amount of erosion over the lifetime of the spark plug.

I would have to suspect after 130 years of spark plug development there is a reason they don't come like that from the factory.

You go down this road so fast ….

Indexing makes more sense to me

Many Alfa engines require 4 side electrode spark plugs like these:

https://teka-alfaparts.nl/teka-alfaparts-we...lugs-605045630/

These have typically been perfectly hemispherical chambers with the plug in the top center

The 964 motor uses plugs like this from the factory:

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It comes pre-gapped.

I tried those once on my 914.
They performed worse, then Capn yelled at me.

That would be enough for me

That's a badge of honor. One of my favorite moments here is when he jumped in my s*** about something.

Long time ago, JC Whitney sold something they called Fire Injector plugs. Similar idea but the outer ground was almost a full circle with the electrode in the center.

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Thats to cool Garland. Look at the list of car's, so many not around any more. But we still have the Singer! AND now you can Charge you Order. Thanks, Mark

Side gap and surface discharge have been around forever...

First surface discharge I hit was way back in the 70s.

Mazda rotary required exotic plugs and about 3 times the energy to fire.

The plugs with 3 or 4 electrodes just give multiple paths for the spark.

Each time it fires it only fires to a single electrode, not multiple sparks to each electrode as the packaging often depicts.

Having 4 electrodes mean as the gap increases on one it becomes easier to make the jump to another electrode and the "gap" increases very slowly over the course of the plugs life.

Those 964 plugs will slowly "square off" the center electrode as it moves to each side ground strap over the course of its life.

Iridium plugs changed all of this...

The multiple electrodes are for extended life and nothing else. Iridium life span for a single electrode made the multi-electrode plug a thing of the past.

BMW was big on multiple electrodes and current thinking has everyone using NGK iridiums.

Do to the clearance inside a rotary the surface discharge is still the way to go (and multiple electrodes if original). I haven't been active in the rotary world so long that I do not know if iridium is available in a rotary plug.

I would not modify an iridium plug but I have cut down the ground electrode to allow better flame propagation from the spark kernel on copper stuff.
By the time I'm modifying the ground strap I'm already "indexed" with the opening facing the largest section of the combustion chamber and "cheated" towards the exhaust valve.

Side gapping a plug is never, never about longevity.
At this level of preparation, the plugs will be consumables automatically replaced at much lower intervals than something I'm using in a road car (which needs to live 50K IMO).

Side gapping and modifying plugs will not do jack diddly shit to a stock or mildly modified ICE engine.

My recommendation is a Iridium single strap resistor plug.
NGK often has "iridium" and "laser Iridium"...
No lasers are used during the making but the ground strap of the "laser" is significantly cut back and pointed to unmask the spark kernel as much is possible.

This "mod" adds 50% to the cost of the plug and is un-needed IMO.
I'm a "non-laser" guy...

home made splitfires! lol

Used to just snip the ground strap back with a pair of dikes so it only overlapped about 1/2 the center electrode....worked OK to help with fouling on engines that should have been rebuilt 50K miles ago.

Some aircraft use "side discharge" plugs. I ran Bosch DTC's in T4's, 911's and Bugs before. Never really noticed any difference.

Dunno why W7DTC is stuck in my head, here's a link for example:

https://www.zoro.com/bosch-w7dtcspark-plug-...ByABEgJRwfD_BwE