NGK has a v-power plug. Any experience with these? I am looking to try plugs in the 8 heat range. ARe these more or les likely to supress detonation?

Sam

_________________

I have no idea about detonation, but I use these plugs in my cars generally. GR4 and GR45 are what I've used. Never had a problem.

Lou

_________________
Home of Slant6-powered fun machines since 1988

The V-power is NGK's standard (non-platinum, non-double-platinum, non-irridium) spark plug. It has a V-notch in the centre electrode to provide more sharp edges from which for the spark to jump and better spark/mixture exposure. There is no effect on detonation. If you are trying to use the spark plugs to control detonation, use plugs with as small an electrode pair as you can find. Smaller (lower-mass) electrodes retain less heat from the power/exhaust strokes; they cool faster and more completely with the intake charge, which makes them less likely to ignite the compressed charge by their retained heat before the spark fires.

See this thread. #8s are really cold...I'll be interested to learn if they stay clean for you.

_________________
一期一会
Too many people who were born on third base actually believe they've hit a triple.

Maybe you can help me Dan. I am looking for a very cold plug with extended reach. I am also looking to gap them around .050. I am looking at the NGK BPR6EY (6427) and the NGK BPR6EGP (7084)
I have a detonation issue that won't go away with the Autolite 64s I am running. I am looking for a big change. Thin wire? Super cold?

_________________
67Cuda,FAST EZEFI,340cu,CR=10.25,RollerCam&Rocker (XR268HR,#20-810-9)(#1622-16)(EddyRPM#60779,#7576), (MSD6AL,#6425) A904, GearVendorsOD, 8 1/4,3.55:1, ClassicAir

According to NGK's book on the NAPA counter, the coldest plug I could find that would fit was the ZFR7F-11, which I had to order. The GR5 is the coldest V power.

As far as staying clean, I would hope the water injection will virtually eliminate that concern. I read the plugs last night after a couple of runs through the gears, and the plugs were absolutely shiney silver metal. Not a speck of dust of any color.

However, a month or so ago I could swear I saw a set of 9 heat range NGK's sitting on the counter of the local speed shop. And, I thought they had the ZFR prefixes, which means they would fit. They said they run 9 and even higher in their turbo cars. But, then maybe they are not running these cars on the street. Even so, I think the water injection would keep them clean. When I went to NGK's web site link on plug temp, they said the only drawback to colder is fouling. So if you have the water to keep it clean, maybe there is no practical limit to how cold you can go.

Dan, what about the plugs that Bren asked about? Can you tell what characteristics these would have.

Bren, you might consider water injection. Go to http://www.alcohol-injection.com/forum/

Take a look at the section on naturally aspirated carbureted cars. See if it sounds useful. It is a pretty cheap way to up the octane of your fuel.
Sam

_________________

You probably already know this stuff, but I thought it might be useful to somebody..

BPR6EGP is the Platinum plug, a BPR6EY would be the Vpower.
I wouldn't spend the extra dollars for Gold or platinum if you aren't fouling them with the water injection going. We ran platinum plugs to reduce fouling in 2-strokes primarily.

A six is considered to be a pretty hot plug in most circles. Our Slants run 4' and 5's in stock trim. With the higher compression engine, and higher head temperatures that are found in highly modified engines, along with improved mixture control, running that hot a plug may not be necessary.
The heat range tells us how well the plug's central core will dissapate heat. If you look at a 4 heat range plug's ceramic, it doesn't contact the threaded grounding surface until deep inside the plug. A 9 or 10 heat range plug has the ceramic bonding to the plugs threaded section much earlier. Conduction is higher, so the core of the plug sheds heat more quickly.
The spark plug can be a source of detonation if the sharp edges retain too much heat. It is generally such a small surface that this doesn't come into play.

If you can run without the projected electrode, I'd try something in a B8ES just to see if it works and doesn't foul. It should be quite a bit less expensive. This plug is not a projected electrode, nor does it have radio interference resistance built into it.
For NGK, E is the long reach thread, and an H is the short reach thread.

With the standard plug you can readily pick up B10ES plugs. They are used in high performance two stroke MC engines, or should I say "Were when I was in the industry." Does anybody run two cycles anymore?

I've run V-Power plugs to good effect in many of my sixes and eights. I was running the GR4's in the Valiant until I went to the projected electrode plugs last change. I can't say that the projected electrode plug works any better than the V-Power did, 'Cause I broke another of my rules; "Don't change more than one thing at a time!"

CJ

_________________
Part of Tyrde-Browne Racing

I run the NGK B9ES plug in my nitrous engine. The short ground electrode works better, with nitrous. I was getting detonation from the ground electrode running too hot, with the extended nose plugs.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Charlie, is the B9ES a shorter plug. Does it reach less into the chamber. What do you think of DI's idea that an extended reach plug increases the timing advance by as much as 5 degrees. So maybe you are reducing the timing as well, which would help with detonation. It is actually encouraging to hear that you were experiencing this, and fixed it with a plug.

The 7 heat range did not cure the detonation, but did help. I upped the water to 7GPH as well, and that helped, but did not entirely cure it. I can go bigger on the nozzel yet, as I have not hit the point where it starts to miss from too much water. That is the threshold you move back from when you hit it.

_________________

The B9ES plugs is not an extended tip plug. Looks like one used in lawn mowers. When I first started using nitrous, I was using Autolite plugs, the same as the recommended for the normal slant with drool tube head, only colder. Kept going coolder, and still had detonation. Will Burns turned me on to the NGK's. What was happening, was not that the Autolite was too high a heat range, but that the ground electrode was too long (extended nose plug). The long length of the ground, would not let the heat to be conducted away fast enough, and the very tip of the ground electrode would get hot enough to act like a glow plug. Don't know about the extended reach plug changing timing, since that is a mechanical function. Maybe the position of the spark in the combustion chamber, has an effect on when the flame front reaches the other side of the chamber. This could determine the timing reqirement of the combustion chamber.

_________________
Charrlie_S
65 Valiant 100 2dr post 170 turbo
66 Valiant Signet 170 nitrous
64 Valiant Signet
64 Valiant 4dr 170
64 Valiant 4dr 225

Thanks Charlie. I know that the extended tip plugs made detonation worse. the ZFR5F produced a very smooth idle, but did present more detonation problems. It might have been in part because the timing is essentially advanced over what the timing light sees. It could also be holding the heat in the electrode as you say.

I am going up one more size on the water, and then will try a set of your B9ES plugs if detonation is still a problem. I am working on reducing the boost a bit too.

Sam

_________________

My advice is to STAY AWAY from any long/extended reach plugs for boosted apps. I believe the Drakes toasted a Simca piston by just switching to those plugs, then switched back and no worries.

Lou

_________________
Home of Slant6-powered fun machines since 1988