I hadn't heard this one before, has anyone done it? I assume there is a downside?
"Side gapping your spark plugs is another way to make a few horsepower. What is side gapping you ask? When you look at a typical spark plug, the ground strap covers the entire center electrode, such as what you see with the plug on the left. This is fine for 99.9% of the vehicles out there, but that full length strap covers, or "shrouds", the spark and initial flame travel. By taking a fine grinder or a good file to that ground strap and removing about .025" or so of material from the very end of it makes the ground strap only cover about half of that center electrode, such as what you see with the plug on the right. Now the spark is more exposed to the open cylinder and chamber which promotes better flame travel rather than shrouding it. Believe it or not, this is worth a few horsepower."
I don't know about this- But I did make sure the plugs on my 460 Ford in my jet boat were pointed(Clocked) into the chamber so that the flame front propagates into the center of the chamber...Had to buy a couple of sets of plugs to get it done....Some people use a shim that adjusts how many turns the plug goes in......(On a 2 valve engine the plugs are off-center, while a 4 valve has the plug centered- No ability to improve the situation there)
My 1977 CVX-20 Jet gets BETTER Fuel economy than direct drive ski boats (best test in Mag' was 3.4 @ 28 mph).....Originally, as tested in Power Boats magazine and by me, my boat got 3.2 mpg at 30 mph......After rebuilding the engine, using ideas from the LS V8s (Tight Quench, relatively hot cam but WIDE lobe separation) and clocking the plugs, plus installing a new-design Impeller in the Berkeley jet, I was able to get 3.78 mpg (1st year after rebuild) and this year (Ten years later) I was able to get 3.88 mpg...Ran the boat the length of Trinity lake and back and refilled the translucent tank to a mark I had made. (34 miles on 9 gallons, and then 33 miles on 8.5 gallons)
Ran the boat the length of Trinity lake and back and refilled the translucent tank to a mark I had made. (34 miles on 9 gallons, and then 33 miles on 8.5 gallons)
Damn, now I remember why I've never wanted a boat.
Yes, yes...I know...They get terrible fuel economy compared to cars......But A) you are not commuting in a boat, and B) I can guarantee that the way I go boating is more fun than.....Well...ALMOST anything.....
The "Prius" of boats is a small boat with a 4 cyl I/O or possibly one of the new small OBs.....8-9 MPG....!!!!
(The reason I questioned the >>Common Knowledge<< about Jet boats being fuel hogs; 90% of the ferries in the world are jet drive- some of that is "Not having anything to damage hanging down"...But if they used a lot more fuel, they would not be that prevalent in ferry service....And then I was able to prove I was right (So there, I was right....ONCE!)
The "New" jetboats- the Jetski-style boats with the buzz-bomb engines, get horrendous MPG....I am MUCH faster(62 vs low 50s), quicker(0-30/3 seconds vs 4.5-6), and get the aforementioned 3.8 mpg, while these new-style jetboats get 2.8-3.3! (And you are turning 5000-6500 at 30 mph! My 460 turns 3000 @ 30)....
Originally posted by 2.5: I hadn't heard this one before, has anyone done it? I assume there is a downside?
One could ask the question, why don't plugs already come side-gapped out of the box? Because of this unknown downside?
One potential downside I see, though based more on a gut feeling, is that as the ground electrode erodes away, the gap on the side-gapped plug would widen much quicker than the gap on the conventional-gapped plug. So perhaps this is good for racing, but not for a torque-it-and-forget it for 100k scenario.
Also, on a conventional plug, for a tune-up, I wirebrush the plug, and then bend the ground electrode if the gap is too wide. I'm not sure if side-gapped plugs can be easily re-gapped during a later tune-up.
I'm not really sure how side-gapping could increase power or economy though.
One potential downside I see, though based more on a gut feeling, is that as the ground electrode erodes away, the gap on the side-gapped plug would widen much quicker than the gap on the conventional-gapped plug. So perhaps this is good for racing, but not for a torque-it-and-forget it for 100k scenario.
I don't think I've ever left a set of spark plugs in any car of mine for more than 10,000 miles before taking them out to have a look. I like to check the plugs to see how the engine has been running. If the side-gapped plugs need replacement due to eroded electrodes (and not being able to re-gap them), then it'll cost ten bucks or so to replace the whole works of 'em. Not exactly a huge cash outlay.
I'm not sure about side-gapping, but my concern is the one expressed above -- copper plugs wear pretty fast, especially in turbo or SC engine.
I remember running platinum plugs with a terrible result in my turbo engine. I believe they were acting as a glow plug, heating up too much.
The newer plugs, the ones that last 100k, are iridium. That metal is extremely rare, but can withstand heat and last with little to no wear. Many people recycle the plugs. Iridium is very rare and valuable.
Originally posted by RotrexFiero: I would think the difference is minimal. Also, how much shielding can the electrode provide?
The difference is pretty marginal when you are looking at a single combustion, but E3 posted video footage in slow motion, the difference in combustion with traditional plugs versus their unshrouded plug electrodes. The result was much more efficiency in burning all of the fuel that enters the combustion chamber. The traditional plugs had good results, but unburned fuel was still present.
That being said, you might view it as the amount of power a full gallon of gas being ignited produces, compared to an attempt to burn that full gallon and having a few ounces left unused.
In the big picture, it's a very strong selling point. The video results are quite convincing as well. Both plug types were indexed, but the E3 clearly showed more fuel being burned, therefore less excess waste exiting the exhaust port.
The problem with this picture is that every backyard mechanic claims the plugs they just installed make a big difference over the factory or whatever plugs they replaced. Sure, they probably had very old, failing plug(s) in the first place. This is an item more likely to see replacement when problems arise, rather than as routine maintenance.
In the end, most claims of superiority (and reviews) are hard to rely on for that reason.
The difference between a "Match and a blowtorch" is not whether, but how fast ALL of the fuel-air mixture combusts...The quicker, the more cylinder pressure, the more power.
FWIW, I tried E3 plugs in the wife's 4 cylinder Ford Escape. There was NO increase in gas mileage and no SOP dyno improvement over the stock plugs with about 50k on them.
My thoughts here but I am not expert.....a plug is a plug is a plug.....colder plugs I get but they still do the same job and perform the same function.
[This message has been edited by Spadesluck (edited 12-29-2017).]
There is a guy in India that cuts grooves in engine heads like that- claims a little 3 cylinder can idle at 300 rpm and gets more power and MPG.....Somender Singh is his name...Been reading about him for at least a decade- Some call him a fool, some call him brilliant....Ex motorcycle racer...
A few years ago Hot Rod Magazine had an article that described the benefits of proper spark plug gap and they provided a formula to follow to set the correct gap. The theory is that the larger the gap the more spark providing that the ignition is capable of providing it. I followed their suggestion on my 454 and found that there was a slight HP increase and a very slight increase in MPG but the engine would stall under hard acceleration if I went too far with it. In their test they did several runs in a controlled 0-60 and a 1/4 mile run to show if there was any improvement (there was). Now if you are curious enough find a safe spot to do a controlled run and try it. Then it will no longer be an opinion but a fact. The Hot Rod formula was to increase the gap by X amount and do a run, over and over until the test times went the wrong way and then go back to the best time but reduce the gap by some figure that I can't recall and let it go at that. I know this does not help answer your question about side gapping but you could follow the same strategy and see if it is of any significant value. Thanks for posting and if it does work please let me know!
I will be snowmobiling this weekend, I may try it on the 2 cylinder 2 stroke 1991 Yamaha Phazer. Though it will be below zero high temps out, so we will see. Even if I do it will only be "seat of the pants testing"
Please.... Side gap is same bs used by Split Fire, Bosch Twin +2 and +4 and Many others. Pepboys, AZ, JC witless and many Many others have sold every kind of gimmicks to "increase power" and/or "improve MPG" for Decades that never works and often does exact opposite to many. When FTC get involved the problem mostly goes to the manufacturer not the vendors sell this crap. Others get Class Action Sued and often go bye bye or change name or some cases still around after but hiding like Split Fire. But again nearly never does a vendor/store loose money for sell the crap.
Worse. 1. Side gap like above can "eat" the center electrode because spark is force to use only a very small part of the center. If work after install, it often will open the gap over a couple thousand miles cause miss fires and other problems. Any Miss firing problems can big problems for the cat and O2 sensors. Spark Miss fires dump raw fuel in the exhaust that cause ECM problems for thinking running very rich and can overheat and kill the cat.
2. Many Gimmick plugs Hate DIS w/ waste spark like DIS Dukes and every engine w/ same coil design. Bosch Platinum +2 and +4 are known problems (search here and many others) and often fails after just a week to a few months depending how much you drive.
SOME plugs shape the ground to nearly point or round the tip like Bosch Super - Pointed Ground Electrode This claim says also opens up the spark but little to no proof their any better. Should work w/o eroding the center.
------------------ Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should. (Jurassic Park)
Originally posted by RotrexFiero: Ogre, What's your thoughts on indexing?
Waste of time and money for most engine. Even most real race operations in NASCAR NHRA etc don't bother w/ this. NHRA teams rebuild whole engine in two hours or less... Many of their engine have two ignition systems and 16 plugs for a V8. They are not going to take time to index 16 plugs.
Even if you find plugs grounds "clock" when put them in same place in one Test hole/head... Threads in other heads are not started the same as test hole or even to other plug holes in same engine and every plug ground will point different.
Index Shims may work but have problems too. It takes a lot of time to use them w/ very little to no result. Worse to many Index shimming can F the head volume for each cylinder. Many engine builders make each compression chamber to be exactly same. With Good tools CC volume variance for whole engine is often < ±0.1cc. Change how plugs will fit in the head like adding/removing index shims can change the volume of each compression chamber. Each time you change plugs, the index shims will change so each time CC volume changes too.
If you really believe will work then Bosch super twin, plat +2 or plat +4 and similar will easier then indexing normal designs. (I think Bosch stop making plat +2 but still find at many stores for now.) Several make Surface discharge plugs w/o normal ground as well based on patent in the 50's. ( https://www.google.com/patents/US2625922 and https://www.google.com/patents/US2790104 ) See https://www.boschsparkplugs...ssary/8/spark-plug/S I believe Bosch and others are just feeding many myths just to make money and doesn't care if they work any better or not. Motor! or Motor Age and others covered problems w/ surface discharge spark plugs but can't find links to old stories. (Motor! and Motor Age are trade rags for car/truck mechanics. Not something most stores carry.)
BTW, my friend swears that if you wax you car and smear baby powder all over it you can pickup an extra MPH in the quarter.
Yeah, probably not.
However, if you have a dark colored car and you get spots where the wax just won't come off without leaving a smear you can use powder or corn starch to remove it.
I spent some time searching the internet last night (very cold here with little to do) for information on side-gapping plugs and indexing.
I found little to nothing supporting that side gapping is worthwhile. In fact, many of the gimmick plugs, that spout this, are reported to be problematic, as Ogre suggested, and just worthless.
As far as indexing, there is some support for this. But, it is not universal and depends on the engine. So it can be effective on some engines. For each engine it needs to be tested.
At most indexing can produce about a ONE PERCENT increase in horsepower. So on a 3800 SC that would be a 2.5 horsepower!
There was no mention of throttle response, or mileage.
In racing 1% increase, or any edge is worth it. But, I think most would consider this just a waste of time. Changes in HP varying more with ambient temps.
Ogre is probably completely right on Nascar (And drag racing too) where they rebuild engines so often......And I KNOW that the threads are differently clocked......Luckily, for me, in my Jet boat, I have not changed the plugs in 10 years! (And I get out to the Delta to ski almost every weekend! (Only 1 hour run time per trip) This year, I have new aluminum valve-covers to install and the exhaust manifolds wrap up and over so I will remove them.....and have easy access to the plugs. So this year I will pull them, clean them and possibly replace them.
Then again, I have only replaced the plugs in my Fiero 2-3 times....And they did not need to be replaced when I did (130,000 miles on original 2.8 and then 65,000 on the 3.4 F-body block)
I would not attempt to index the plugs on my Fiero- She is my daily driver....My boat, I had a winter to install and complete the engine (November to March)......And I was trying for efficiency, not just HP.....Indexing would not work for 4 valve engines...Only 2 valve with offset plugs
Actually, indexing can work with 4 valve cylinder heads. From my reading, and who knows who's thinking or experience I'm referencing, you have to know that engine. Perhaps it means aiming the plug between the two intake valves. I don't know.
I think there is some merit to indexing, but I would like to see some controlled experiments.
Just in thinking, I can see it promoting better efficiency in smaller single engines where there is not as much scavenging going on.
But, it may be the effect is more beneficial at higher RPMs.
I didn't cut my plugs on my sled. Yeah I'm sure cutting it off decreases plug life, that only makes sense. On a technical note saying its like Split Fire or E3 hype isn't right IMO, they add more shrouding to the spark and side gapping removes shrouding, that is its point. Good conversation about it
