Save Gas And Incerase Horsepower By Side Gapping Spark Plugs

Side gapping spark plugs has been use in racing for years to increase horsepower by unshrouding the spark thus allowing the flame created to propagate faster resulting in a more complete burning of the fuel/air mix. Many manufacturers offer plugs deemed racing plugs that are side gapped but at inflated costs. By doing it yourself you can use a cheap .99 cent plug to save money and increase horsepower.

Step 1 Cuttting ground electrode

Using a dremel with a cutoff wheel or a hacksaw you will need to cut the ground electrode even with the edge of the center electrode. You need to be careful not to hit the center electrode or the porcelain.

Comments

[Pizzapie500]

Set the gap? What does that mean?

[bmj67]

You need to set the gap between the side and center electrode by first measuring and then bending the side electrode in or out.

[suzukikatana]

Advance the timing and have the thing ping its head off great. Duh

[Detroit wagon]

This hack leaves less surface area to conduct a spark at the correct gap distance, the result of which means more frequent regapping and/or spark plug replacement. If it does work as described by providing better combustion, it's great for racing but less practical for your average driver. I second the request for numbers. Less blurry pics would be awesome too.

[mpikas]

Wear is not really a concern, the fact is that conventional plugs are "worn out" before you'll see significant gap erosion, at about 10-15K miles.  Secondly, when I side gap plugs, typically I leave a slight bit of overlap over the edge of the center electrode so worst case, I can take a file and give it a nice, sharp edge.

I've tested this on a couple of engines, and will suggest that you will have a very hard time showing a measurable improvement without other changes.  What this does accomplish is that the same ignition system will fire a significantly larger plug gap reliably and will expose more of that spark to the chamber, and there taking advantage of that you will see a measurable improvement.  For example, a vehicle I did this on about 15years ago had specified a .036" gap, and would start having a noticeable miss with gaps in the .042" range with the rest of the ignition optimized.  With side gapped plugs with sharp edges, the ignition ran reliably with .065" gaps, where I was able to document a significant increase.

[james.mcglashan]

can you please update the video it doesnt work???

[OBar]

I drive a four cylinder Chevy S-10 in desperate need of an oil change. ( I dunno why I felt the need to inform you of that) I used to work for a man who built and drove race cars, and he said that for a daily driver car, regular maintenance and care goes a long way.

[joeofloath]

Does this work for 2 strokes? I have an old quad I'm converting (instructable coming :)) and it might need some more power...

[ajilitee]

What about those fuel additives? I am getting desperate my commute is getting out of hand.

[DamionLee]

Fuel additives are fine if you want to add something occasionally to clean your engine, but you would be better off using a product like 10K for that. With regards to performance, fuel additives add elements to your fuel which will not burn as well as the petrol. What happens with most fuel additives is that you lose horse power. They are a great scam in that regard.

[gin_road]

Hey, my Kawasaki ZRX-1100 uses this technology. It uses an NGK plug#CR8EK. This plug not only uses the side gap technology, it doubled it!!!, It has two ground electrodes on the plug placed 180 degree's apart. Only one downside, 8 to 10 bucks a piece.

[trebuchet03]

From the horses mouth:
NGK FAQ

There are some exceptions, though. Extremely high compression cars or those running exotic fuels will have different spark plug requirements and hence NGK makes spark plugs that are well-suited for these requirements. They are classified as "specialized spark plugs for racing applications". Some are built with precious metal alloy tips for greater durability and the ability to fire in denser or leaner air/fuel mixtures. However, installing the same spark plugs Kenny Bernstein uses in his 300+ mph Top Fuel car (running Nitromethane at a 2:1 air/fuel ratio and over 20:1 dynamic compression) in your basically stock Honda Civic (running 15:1 a/f ratios with roughly 9.5:1 compression) will do nothing for you! In fact, since
Kenny's plugs are fully 4 heat ranges colder, they'd foul out in your Honda
in just a few minutes.

and

Some of these "specialized racing plugs" are made with precious metal alloy center/ground electrodes or fine wire tips or retracted-nose insulators. Again, these features do not necessarily mean that the spark plug will allow the engine to make more power, but these features are what allow the spark plug to survive in these tortuous conditions. Most racers know screwing in a new set of spark plugs will not magically "unlock" hidden horsepower.

I'm also more inclined to believe a company that makes an anti-claim over one that makes a claim (Especially without data to back it up):
NGK as a company tries to stay clear of saying that a racing spark plug (or ANY spark plug) will give you large gains in horsepower. While certain
spark plugs are better suited to certain applications (and we're happy to counsel you in the right direction) we try to tell people that are looking to "screw in" some cheap horsepower that, in most cases, spark plugs are
not the answer.

[pyrotmaniac]

This rings very true, in one of the first hot rods I built in the early '90s being at the time just a teenager. I thought that I had done enough to warrant changing to specialized plugs of this sort. Simply adding a larger carb. and exhaust to an engine will not even bring you into the ball park of needing this type of spark plug. The car I was building at the time never ran 100% untill I replaced the $10.00 spark plugs for some good old champion $.99 units. sure you change them when you change your oil (well almost that often) but who cares. For your daily driver you should be popping the hood every couple of weeks just to check on everything anyway.

[bmj67]

I never said you had to just use the plug in your car or truck. There are many motorcycles and atvs that have compression rations above 10:1 stock. Also there are cars that come from the factory with turbos and superchargers. They are not your average Honda civic.

[trebuchet03]

That's fine and all - but again, I stand that a claim requires empirical evidence to be believable ;) There are cars that have dynamic compression - these are the minority on the road as with higher compression engines.

Finally, I'll reiterate the NGK statement to the purpose of this modification...
Some are built with precious metal alloy tips for greater durability and the ability to fire in denser or leaner air/fuel mixtures...
(running Nitromethane at a 2:1 air/fuel ratio and over 20:1 dynamic compression)...
these features are what allow the spark plug to survive in these tortuous conditions.

[nibbler125]

ill try this i have a 3 wheeler that likes to miss and load up allot

[picbuck]

But...if it were that easy to increase mileage and horsepower...wouldn't the manufacturers be doing it? And bragging about it in Superbowl ads? Well...just a thought.

[eskimojo]

Not necessarily, commercials(especially those showcased during the superbowl) are dictated by trends and marketing plans. There have been plenty of technologies that have gone basically unnoticed by the general population simply because they are unpopular or don't fit into the "American Way"(basically quick/easy/cheap).

[picbuck]

My reference to the Superbowl was, of course, a metaphor. Meaning a manufacturer who comes up with a better way tends to shout the news from rooftops (also metaphorically). On a more basic level, the media--both print and electronic--have long since fallen into bash-America mode. But the view that "they" (any they) are better than America is mistaken. Europe curses us for what they call our effete central heating and air conditioned cars. But we don't want to keep such things to ourselves, we want Europeans to have them too. Compare the two ethical stances, and decide which is better. While in the East, Japan and China--among others--have a more productive view. They want to be us. The American Way can be very simply stated: you're as good as the next guy, and you can take your shot the same as anybody else. If anybody can find fault with this view then they are, as far as I'm concerned, welcome to their opinion. That's another thing about the American way: you can have your opinion, you can state it as loudly as you like, and all Americans band together to protect your right to do so.

[Tightwad]

Ok, lots of people seem confused by various Spark Plug terminology. First: Hotter/Colder- The spark is not "hotter" or "colder"...it's a spark. Gap size is set/determined by the ability of the ignition coil to bridge the gap. The stronger the Coil, the wider the gap can be...wider is better because it opens up firing area a bit more. Hotter/Colder actually refers to the plugs ability to bleed of heat. If you look down into the spark plug, you will see that the ceramic inslator portion is different lengths on different plugs. This is what determines the "heat" range. Having a hotter/colder plug is not better/worse...rather you need a plug that will run at the optimal temperature for your application....Motors that run hot using Alcohol or similar need "colder" plugs to help reduce the change of the spark plug turning into a glow plug. Spark Gap/indexing...this mod- This will, for 99.5% of the people out there, have no positive effects in their applications. This doesn't make it bad, or false advertising, simply not beneficial. There are so many other places you lose power and effeciency that making up for it in this one place will not be noticable. This would be the LAST thing you do after you have upgraded/improved everything else along the way. Opening up the ignition area, or indexing your plug relative to the Intake Valves works, but is only quantifiable in high-performance applications where everything else is already optimized. Downsides to this mod - As others have pointed out, you will get more wear from this mod, and thus will need to adjust/change your plugs more often. There are no negative side effects otherwise, simply shorter life span of the plug and gap setting. Regular plugs will NOT work better than plugs correctly modded this way. "But I felt a difference"- Sorry, but there isn't anyone short of a seasoned racer that could feel the difference that JUST this mod makes. You can't feel a 1-2 HP increase(if you even get that) by the seat of your pants....1-2 HP is less than 2% gain. Tightwad ASE Certified spoilsport

[eskimojo]

Thank you for clearing that up, it's good to hear a voice of reason every once in a while on the internet, even on this site.

[Malaachi]

Won't they foul faster?

[eskimojo]

If this does in fact burn fuel more efficiently, I don't personally know, than theoretically... yes it should foul quicker. Fouling is a result of carbon deposits left from ignition, however you are also burning more fuel per stroke. Petrol engines are famously inefficient at fuel usage. A very large percentage, I don't have specs sorry : (, of gasoline is pushed out through the exhaust. That's why modern vehicles in the US are required to have Catalytic Converters; their purpose is to burn any unburned fuel and lower Carbon/Nitrogen emissions.

[crakarjax]

If you want the fuel to spark faster, advance the timing. Duh.

[RiddleOfSphinx]

Well, I tell you what bmj67, I'm gonna try it ( Yes, it's my choice and it always will be...that's the great thing about this government after all, right ? ) But I'll let you know how it turns out. as "positively" and as "constructively" as I can manage :D

[bonwebb]

Wow. Keep this thread going. I might just coalesce it all, go back to college, and have my master's thesis in my back pocket.

[LasVegas]

Honestly, I can't see how this would improve mileage or horsepower. A spark is a spark whether it's covered or not. The compressed gas/air mixture is completely surrounding the area. Any spark will ignite it equally well. All I can see this doing is shortening the life of the plug by reducing the area of the spark. Less area to foul, quicker fouling. Now, perhaps shortening the gap might produce a slightly hotter spark, but this could be done without cutting the electrode. Like kudoskun, I'd like to see the numbers.

[Prometheus]

"A spark is a spark whether it's covered or not. The compressed gas/air mixture is completely surrounding the area. Any spark will ignite it equally well." Speaking of "anecdotal"...If a spark was just a spark, then proper gapping would not be essential for ideal combustion. This is why deposits between the electrodes will hamper the spark severely, even if it is not blocked. My racing friends and I got a huge laugh out of this one... Fouling is not the result of surface area, it is a result of the plug "burning" too cold. Brushing up on your internal combustion theory might help.

[BlessedWrath]

Deposits between the electrodes act as dielectrics. The spark plug fails, not because it's a different spark, but because the plug has more non-conductive material to travel through to establish an arc. "Brushing up" on your electricity might help.

[Prometheus]

"Deposits between the electrodes act as dielectrics."

If anyone needs brushing up, it's you:

http://www.gnttype.org/techarea/engine/plugs.html

Class dismissed

[BlessedWrath]

Showing me a spark plug website does not change how electricity works. Your "class" is based on ignorance. Do not bother to reply to this. I consider the matter closed. You have nothing of value to say to me. You are dismissed.

[Prometheus]

I'm not one to typically validate such spectacular ignorance with a reply, but I was making artificial plasma conduits and lasers before you could even spell "battery". Your attempt to prove yourself so knowledgeable by ignoring the obvious does not validate your "supposed" knowledge about electricity whatsoever. I've been working with electricity and radio longer than you have been alive Sparky. I have a significant background in auto-racing, and I am a professional mechanic and jack-of-all-trades to the likes of which you will never hope to achieve. I think that with all my schooling and all of my experience that I know a bit more than someone like you who has yet to post any project whatsoever because you are too busy being a troll on this site. If you actually look at the site I posted instead of simply insisting you are right and everyone else is wrong, you might actually see that fact supercedes your anecdotal knowledge on electron flow and automotive technology. Your lack of experience in high-voltage and automotive engineering shows, so you best leave good enough alone here and stick to something you might have experience in. Sad to say, but you are incorrigibly irrelevant to this project, please go away.

[Prometheus]

On topic (before someone so rudely but creatively attempted a flame-war), cutting so much from the ground electrode has been of some concern, and honestly I don't cut them that far back. I suggest cutting it to about halfway over the anode (center electrode) and then filing between both to make the gap angular to about 40-50-degrees. As a rule, I don't bend the ground electrode more than 5 times in the plug's service life to prevent excess fatigue that might burn it off and create valve-destroying foreign material loose in the cylinder. An alternative is to consider "surface-gap" plugs, if you can find them for your engine. They have no obstructive ground electrode and provide a significantly more consistent ignition ratio.

[abross]

Not trying to be mean here or start another war, wouldn't everything you just said contradict what you said earlier about how cutting back the ground electrode is just a waste of time. Earlier you said, "A spark is a spark whether it's covered or not. The compressed gas/air mixture is completely surrounding the area. Any spark will ignite it equally well." Now you're saying, "I suggest cutting it to about halfway over the anode (center electrode) and then filing between both to make the gap angular to about 40-50-degrees. As a rule, I don't bend the ground electrode more than 5 times in the plug's service life to prevent excess fatigue that might burn it off and create valve-destroying foreign material loose in the cylinder." and "An alternative is to consider "surface-gap" plugs, if you can find them for your engine. They have no obstructive ground electrode and provide a significantly more consistent ignition ratio." So you're entire rant is just contradicting itself.

[Prometheus]

No, I didn't say that "A spark was merely a spark", I was merely quoting the above error by saying this was not true. Putting this in quotes was necessary because the site format does not appear to support "quote" tags. What I was saying was that the spark can vary greatly with a seemingly insignificant variation on the gap, and how it travels from point A to point B. You are not starting a war, you made a reasonable and mature response, even if perhaps you misread my comment. No harm done.

[LasVegas]

Actually, earlier I said that about the spark. I still stand by it. Of course the gap makes a difference in the temperature of the spark. Shorting the gap, whether the electrode is shortened or not, will make the spark hotter and burn up the plug quickly (especially with a standard steel plug). Increasing the gap would spark cooler and foul the plug quicker, especially with less area to foul.

I didn't respond previously because, frankly I saw it as a lost cause. I only responded this time because your argument claims a contradiction that doesn't exist.

[Prometheus]

Hey, if you got something to say, say it. It just seemed to me that you were saying that a particular gap was not important in generating a proper and healthy spark. I perhaps misunderstood your issue with the fouling as well, but now I see the point you were making, being that of a cooler spark fouling the plug due to delayed (or missed) and lowered combustion temperatures. I will restate that even a 0.010 mm difference in a spark gap will significantly change the quality of the spark as it pertains to ignition of a fuel mixture, which is why a proper gap is important to efficient operation of the ignition system (too short stresses the coil itself; too long and the spark is too weak to fire the cylinder reliably). Even "safety-gaps" in older televisions had to be made with a degree of precision, to properly bleed-off overvoltage spikes from varying line voltages passed through "dumb" power-supplies that would allow the surge through. As to what this contradiction is, I am unsure. I am not above admitting an error if I may not have posted in a manner that avoids confusion, so if you could clarify, had my previous post not cleared matters? I'm glad the passing majority here can think reasonably and with some maturity. Maybe someone should actually try this and report on their results instead of all this speculation. I for one, know it can help by theory alone, as well as practical experience. I for one could suggest a more radical approach that would turn any standard plug into a lightning rod, but most would not find it cost-effective. As a final tip, sparks like to jump off of sharp, pointed edges the most, this contributes to a worn-plug's misfire, and why the anode is so rounded on a worn plug. This theory can be observed by seeing iron filings collect on a magnetized knife blade...

[trebuchet03]

All I can see this doing is shortening the life of the plug by reducing the area of the spark.

Which is very likely the reason you don't see these mass produced ;)

Honestly, I'm willing to bet this is one of those things that works great for high performance racing engines that doesn't quite carry over to mainstream with the same results...

Of course, empirical data - from a typical road car - is best :)

[arkansascajun]

sidegap is how multi-element plugs like SPLITFIRES are made.

[Phoghat]

I'm older than dirt and have been using this since 1964. Phoghat Street Racing is my life