Thinking of Platinum+2 spark plugs Options

[Porschef]

They're supposed to burn a little better. Also considering jumping up one heat range.

Any suggestions welcome, thanks.

Joe

[Root_Werks]

Never had much luck with platinum plugs in air cooled engines.

W7DTC or W8DTC would be a good choice, 8 for slower in-town driving, 7 heat range for the freeway driving.

[underthetire]

Platinum plugs really only work well in high discharge ignition systems. They will work, but kind of a waste of money on stock ignitions IMO.

[a914dude]

They suck in air cooled motors. Splitfires are worse.

[Cap'n Krusty]

They're supposed to burn a little better. Also considering jumping up one heat range.

Any suggestions welcome, thanks.

Joe

They're junk for use in aircooled engines. In fact, they're junk in all VW applications. Regular plats are junk, too, and so are the 4s. Why would you want to "jump up" one heat range? Your engine calls for W7CC (NGK B6ES, 'cause their numbering system is backwards). Very late T4s (heavily smogged-up Bus explodermobiles) used a W8CC. Extended tips are not indicated in this application, at least for a stock configuration. Jake may have other opinions about that.

The Cap'n

[Porschef]

Thanks for the replies.

The reason I ask is that the original WR7CP is discontinued, although I'd imagine they're available somewhere. I tend to drive mostly around town, and seem to get fouling. But that's another question.

Thanks,

Joe

[Porschef]

Cap' n,

Your reply came in before I could finish mine. May I ask what you'd recommend?

Thanks

[VaccaRabite]

I am wondering about spark plugs too. My plugs seem to foul pretty easily and I wanted to try the next heat level.

Zach

[Jeffs9146]

I tend to drive mostly around town, and seem to get fouling.

This indicates you should step up to a hotter plug maybe a BP6ES! This is what I ended up doing on my 67 911 and it ran MUCH better!

Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.

[Cap'n Krusty]

Try W8CC, or NGK B5ES. That's as hot as you wanna go. In fact, there may not be any readily available hotter plugs. Shifting at too low RPMs will affect plug fouling, too. If you have carbs, 8s are the way to go with modern fuel and the tendency for carbs to run a LOT richer than EFI.

The Cap'n

[VaccaRabite]

Thanks Cap'n. I am going to get some of the W8CC plugs tomorrow.

The around town fouling is pissing me off.

Zach

[Cap'n Krusty]

I tend to drive mostly around town, and seem to get fouling.

This indicates you should step up to a hotter plug maybe a BP6ES! This is what I ended up doing on my 67 911 and it ran MUCH better!

Carbon fouling occurs when the spark plug firing end does not reach the self-cleaning temperature of approximately 450°C (842°F). Carbon deposits will begin to burn off from the insulator nose when the self-cleaning temperature is reached. When the heat range is too cold for the engine speed, the firing end temperature will stay below 450°C and carbon deposits will accumulate on the insulator nose. This is called carbon fouling. When enough carbon accumulates, the spark will travel the path of least resistance over the insulator nose to the metal shell instead of jumping across the gap. This usually results in a misfire and further fouling.

If the selected spark plug heat range is too cold, the spark plug may begin to foul when the engine speed is low or when operating in cold conditions with rich air-fuel mixtures. In some cases, the insulator nose can usually be cleaned by operating the engine at higher speeds in order to reach the self-cleaning temperature. If the spark plug has completely fouled, and the engine will not operate correctly, the spark plug may need to be cleaned / replaced and the fouling cause identified.

A B6 is a bit hot, 2 heat ranges hotter than the original specs. And early 911s don't use extended reach plugs. What you really need to do is install a CDI like the factory did ..................

Edit: Lemme rethink that. With "modern" fuels and Weber or Zenith Solex carbs, an NGK 6 is probably necessary, even with a CDI setup. Extended reach plugs are still questionable. The original plugs are of a design that's NLA, and they were sort of half way between a standard reach and an extended reach design.

The Cap'n

[Jeffs9146]

Lemme rethink that. With "modern" fuels and Weber or Zenith Solex carbs, an NGK 6 is probably necessary

Yep, running older Webers (ie: running a bit rich) mostly around town to and from work!
The hotter plugs worked well for not fouling.

[70_914]

They're supposed to burn a little better. Also considering jumping up one heat range.

Any suggestions welcome, thanks.

Joe

The fine wire center elcectrode on the Bosche platinum series of plugs is very prone to fouling out. If your car is running rich you will drop cylinders at idle. Been there, done that, won't do it again.

[Jeffs9146]

(IMG:style_emoticons/default/agree.gif)
When I tried to run the platinum plugs they were missing all of the time! When you wanted to move and hit the gas they would miss!

[VaccaRabite]

I am dealing with that now with the stock heat range copper plugs (weber dual carbs). I have been fighting low speed fouling all summer. I know when my engine gets hard to start that its time to pull and clean the plugs, but you can't do that when sitting at an intersection in Baltimore and the car is trying to die on you at idle.

Zach

[Jake Raby]

I learned about platinum plugs in the early 90s... They blow! The newer ones have been no different in my experience.
We see benefits with them in modern engines, but that's the extent of it.
I stick with the Bosch copper plugs.. I have one engine making 620HP with a set of them, they work.

[Root_Werks]

Frug and egg, you guy's don't listen. (IMG:style_emoticons/default/rolleyes.gif)

I gave part numbers, if you like Bosch coppers, you'll love these:

http://shop.advanceautoparts.com/webapp/wc...ci_sku=25964618

You can get them in 7's or 8's depending on FI, carbs and driving habbits. I've run them for 20+ years, love them.

Getting harder to find though.

(IMG:style_emoticons/default/driving.gif)

[VaccaRabite]

Is there an appreciable difference between the Bosche or NKG plugs and the more common Autolite or Champion plugs that they cross reference with? Reason being, I was unable to find the W8CC or NKG B5ES plugs anywhere in town. But everyone had the cross referenced Autolite and Champion plugs.

Is there a difference? If so, what is it?

Zach

[Drums66]

...Answer to your ?....no no no (IMG:style_emoticons/default/wacko.gif)
(IMG:style_emoticons/default/bye1.gif)
(ngk come to mind)