side gapping spark plugs

[LETZRIDE]

apparently a racing secret since the 60's...first I have heard of it.

Let's here a discussion.

Here is some background info for anyone else like me who hasn't heard about this before:

Just like indexing a spark plug (concept wise) you chop the top portion of the plug off so that you get a bigger spark that is exposed directly to the mixture.

http://performanceunlimited.com/docu...degapping.html

Discuss!! :drool:

[2.8 Bird]

Re: side gapping spark plugs

I know if you have force induction that's not a good idea to do. NA perhaps, but then again you still have to balance this with proper fuel mixture. Or else, detonation.

[LETZRIDE]

Re: side gapping spark plugs

I actually read a few things that said it is great for FI as it reduces the chance of having blow out?

[Pewter02Camaro]

Re: side gapping spark plugs

I would imagine that it would change the way the flame kernel acts within the combustion chamber. Keep in mind that when engineers design cylinder heads they are most likely working under the assumption of a standard un-modified plug. So it may actually cause degradation to the efficiency of how the A/F burns.

Just thoughts off the top of my head.

[LETZRIDE]

Re: side gapping spark plugs

I would imagine that it would change the way the flame kernel acts within the combustion chamber. Keep in mind that when engineers design cylinder heads they are most likely working under the assumption of a standard un-modified plug. So it may actually cause degradation to the efficiency of how the A/F burns.

Just thoughts off the top of my head.

Explain? or keep thinking out loud lol

the stronger the spark generally the more power you can make no? That's why guys love Individual coil packs > our coil packs > rotor/cap

Isn't that also the philosphophy for why guys buy MSD ignition setups and bigger wires etc?

[Pewter02Camaro]

Re: side gapping spark plugs

Explain? or keep thinking out loud lol

the stronger the spark generally the more power you can make no? That's why guys love Individual coil packs > our coil packs > rotor/cap

Isn't that also the philosphophy for why guys buy MSD ignition setups and bigger wires etc?

Having different coils or wires wouldn't change the kernel, only make the spark stronger. I'm trying to find some pictures/theory on the spark plug shape thing I'm tossing around. I could be completely off track with this though. LOL

[Pewter02Camaro]

Re: side gapping spark plugs

Check this out.

http://www.tvu.com/PCycleByCycleweb.html

I think this may help you understand what I'm getting at.

Look for a picture labeled #13.

[2.8 Bird]

Re: side gapping spark plugs

That's hotter spark but you want to be in the cold range with FI. This is indeed a popular mode with hot rodders but they were running with lead base fuel and very high octane. Not a good idea if you run with regular fuel. Also I heard someone mention that this type side gapping is used mainly for drag racing and not for everyday normal driving. Those people who race with this often replaced them after each race.

Here's a good site of how side gapping is done.

http://www.instructables.com/id/Save.../?comments=all

[LETZRIDE]

Re: side gapping spark plugs

Interesting points...is this not still used while racing though? where guys arent using lead anymore?

Check this out.

http://www.tvu.com/PCycleByCycleweb.html

I think this may help you understand what I'm getting at.

Look for a picture labeled #13.

I'm having a tough time understanding whats going on here? I might need to read the whole article when I have some time.

[WarShrike]

Re: side gapping spark plugs

Guess you haven't seen MotoGP or F1 plugs. This is some neat stuff, called a surface gap or surface discharge spark plug. Such close tolerances between the piston and combustion chamber + valves leaves little to no room for the electrode to stick out.

In order: F1, GP Bike, Ford Focus

[3.4grapeofwrath]

Re: side gapping spark plugs

I have a set of autolite plugs that I modified awhile back. I used them in my turbo 3500 engine and did notice a difference in performance but pulled the plugs in favor of a set of ngk non-projected plugs. My theory was the less of the spark plug tang hanging out the less chance it would have to heat up and cause detonation.