Well I just read a previous post with regards to spark plug sidegapping. I have never heard of this but as I read further it was described how to do it. My question, how many out there have actually done this and found it beneficial? If I see enough positive responses I may give it a try myself.
I worked in a shop for years and never heard this trick so I'm really curious now.

 

I have never sidegapped a set of plugs but I recently purchased two sets of Autolite racing plugs to handle nitrous on top of my blown Corvette...they came from Autolite allready side-gapped!:-staun

 

What is sidegapping?

 

To side gap a plug you grind off the ground electode about an 1/8th of an inch. It opens up the spark to the mixture. I haven't noticed a diffence when I tried it but lots of racers do it.


Bear Tracks

 

I shall look into this tomorrow but if Im not mistaken there are a couple of brands of spark plugs at a few stores here that sell plugs that are actually made like a side gaped plug. I cannot remember the name but the more I thought about it the more it reminded me. I shall let you know if I find them.

 

They are the Bosch plugs. Platinum 2 and Platinum + 4.

 

[updated:LAST EDITED ON 27-Jun-02 AT 11:20 AM (EST)] I tried to buy the bosch plugs but they don't list them for 351c/m or 400.

Bear

 

Ok my question is this. How many of you actually see 6500-8000 rpm on your engines? That's where the bennifet of side gapped plugs comes in.

 

> I tried to buy the bosch plugs but they don't list them
>for 351c/m or 400.
>
>Bear

The number for the ones I use is 4449 ... You have to do 30 rounds of cross referancing to find it but I did ...
I did have one plug foul out so I'm thinking they my be to cold so when I went back to try to find a hotter one the counter person was lost. and you think you could just ask for a 4450 or 4452 nope don't work that way.

 

Thanks for the number Shazam. I'll try to do a little web research on the plugs.

Bear

 

I side gapped my plugs last summer. I used autolites, and since I have the full MSD system I knew the spark was hot enough to bridge the extra space. If you read all of the info availabe side gapping is supposedly an old racing secret and supposed to really generate gains. It makes sense in theory, because it unshrouds the spark kernel to the combustion wave...provided you have a hot ignition. Anyways, I very carefully followed the instructions (I used to have a website that went into this with pics and all) and my results were: Crap! My truck was NOT happy with this mod. The low end was worse and the high end not much better. Maybe it works better in light weight race cars, but it worked crappy in my truck, even with my hopped up 428 Cobra Jet. Just thought I'd give ya some real world experience. Oh, and after my poor experience I called my buddy who races circle track (and has for the past 17 years)and he had never even heard of side gapping. Go figure.

 

I run NGK v-groove plugs, and gap them over to .060", to flex the muscle of my MSD 6A, Blaster II, and Street Pro-Billet Distributor. I just found out today that my truck runs on 87 octane! I figured it would be pinging all over the place, but even with 36 degrees total timing, 9.7 static compression, and 194 psi of cylinder pressure, it still doesn't ping, even under full load sitting in traffic! How's that for an efficient combustion chamber! Did anybody read the HOT ROD buildup of that 1,050 HP stroked big block last month? that thing made over 1,029 HP 20 times in a row, and it breathes with it's own lungs, no SC or Turbos. The point is, he had 11.0:1 compression, and ran on 91 octane! timing went as high as 38 degrees total, and never pinged. The plugs were indexed, so that they are the perfect height, and the ground electrodes all point in the same direction, which was found experimentally to produce maximum power. It's a little thing, but when you're making 1 Kilo-HP, even a little thing can be worth 20.

*sorry, off topic, just for what it's worth*

'77 F100, 302 (the aftermarket Prodigy), C4
Cadet Second Lieutenant John F. Daly III
South Carolina Corps of Cadets, The Citadel
The TorqueKing

 

I like the NGK v-grooves and I don't side gap those. You shorten the live of your plug by about half. Most race plugs are already side gapped and we noticed a marked improvement in our pure stock 4 cylinder when we side gapped the stock plugs. I did side gap a couple of sets for my truck and I saw an immediate jump of 10% in gas mileage and I watched very closely (and I never turned the engine much more than 3500). Our current Grand Stock race car turns about 6400 on the top end and all the plugs are race plugs that are side gapped from the factory.

 

Hey Slick I have a question;

If you got a 10% increase in mileage by sidegapping your plugs then why are you using the NGK? Cost? Do the NGK give you better mileage than factory plugs without sidegapping?
Just curious.....