Multiple ground electrode designed spark plugs significantly slow down the early flame development, due to the increase in heat loses and the reduction in flame growth due the restricted flow directions. it has been found that regular spark plugs with a thinner electrode can achieve better performance. I have no favorites!

Hope they do a great job for you :thumbup: If you find them

Jester

 

The biggest question is why? Those bosch plugs you mentioned stopped being produced due to performance issues. they caused more problems than they solved. I witnessed a brand new set cause misfires when installed in an engine per customer request...The engine called for standard plugs, which cured the misfire when changed.

Most "gimmick" plugs like that have stopped being produced because they simply do not work. You're not going to find them because of that. There are some variants out there in the racing plug market such as brisk, but they are highly specialized and expensive. When used in an application that they are designed for, they are ok. But anything else and they are generally much worse than a cheap standard plug. There are many tests out there that clearly demonstrate that.

To each is own, but I won't recommend anything other than a standard style plug for 99% of the applications out there.

 

Theyre still in production ( Or a different variant of them, and even OEM on loads of (european) vehicles.)
I sell loads of these every year, but my part catalogues dont have any tapered plugs.
Why? Less wear, less misfires and no indexing required. There is a whole lot more to an engine than what a dyno measures.

 

I haven't seen them listed for years for any application. I will completely disagree on misfires, I've seen them misfire on pretty much every application I've ever used them on, which includes USA, European, and Japanese imports. Stopped using them for just that reason, and they foul very easily as well. I'm not talking about "dyno" results either...On road results...

As to the indexing of spark plugs, it's an old school deal that did not provide any better combustion, power, or anything else. It's sole purpose was so the ground electrode would prevent from hitting the piston when it was at TDC. On that, I've seen HUNDREDS of examples that proves just that....

The exotic electrode plugs simply don't live up to the hype.

 

Not really arguing, but to add to the conversation my father-in-law’s 86 Volkswagen Scirocco is likely the exception that proves the rule

About a decade ago I did the spark plugs for him and I used a standard Bosch platinum plug ignoring the factory recommendation to not use a standard plug. Always having good luck with that plug (up to that point - now you couldn’t give me one) threw them in.

Never did run right. Always cranked for a long time before starting and generally didn’t run right. Was ok at first but got progressive worse until the last few years when I put in a set of true side gap plugs from NGK. Nothing special, Other than this is the plug listed by NGK for this engine.

Several years later now and it still fires off right away and runs a whole lot better. I always thought it was just a byproduct of Volkswagen’s goofy fuel injection of the time that made it run bad. Turns out that a standard plug just doesn’t work well in this particular engine.

Going back to the Bosch platinum +2 and +4, I always have wondered if those would work well in this engine. I would have tried them years ago but they were double and Triple the cost of the standard platinum plug.

I don’t know what happened to Bosch plugs since then. They have not served me well for the better part of a decade now. I used to use them in everything and would get a solid 60k service life out of them. In the last 5-10 years though, they had been giving me misfires inside of 20-30k miles. This after going through 2 or more sets lasting 60k in the same vehicle. Changing them out to the NGK G-power has fixed every single one of them. The G-power is my go-to plug for everything now if available. Probably one of the best and most affordable fine-wire plugs on the market.

Shown below is the BP6ET plug for the scirocco. Very cool looking plug. If this style was available for other applications I’d try them just to see. Advertised as a 30,000 mile plug.

 

https://www.sciencedirect.com/science/article/pii/S2090447912000883

Read it ! it may surprise some of you . especially the final test result ! "Impact of spark plug number of ground electrodes on engine stability"

JESTER

 

Interesting study. Its complements my findings on the dyno with the brisk ZC series plugs. ( My all time favorite, but too long for my application).
Problem with those electrodeless plugs is that they arent really good (in my experience) on a road car. See them foul up too easy.

 

My dyno says otherwise . Especially the ZC plugs. But this is the exact reason I stated I did not want any discussion here. Just a part number of a multi ground plug for an SBC. Given that I cant use the ZC'S as rheyre too long.

 

Problem is saying 350 chevy....what year? Depending on year, they take different plugs....some take a .460" tapered seat, some take a 3/4" gasketed plug.....that's the most widely produced engine in history...need more specifics...

 

Look for .460 reach tapered seat....you won't find a metric listing for a 350 that I'm aware of.....

Been looking at computer screens (plural) for two steady weeks nonstop....I do tend to miss a thing or two now.......

 

Try this site:

https://www.boschautoparts.com/en/auto/spark-plugs

You'll need to punch in vehicle information to get the right part numbers. So year of engine and make up an application....if needed...

 

I just did a quick search, that particular plug is not available for a 350 chevy...you may need to look up other applications....

 

Interesting Video:

 

Quote: "this is the exact reason I stated I did not want any discussion here "

This is "HOTRODDERS" NOT A CHURCH ain: that tells people not to question what they are told!! This site is designed to teach, inspire, guide and improve peoples ability's and joy in the HOTRODDERS life style and your statement ridicules the entire purpose of Hotrodders BAD INFO is not allowed on here and people disagreeing and suggesting different opinions is part of learning and proving something is right or wrong !!! If you want no discussion or debate don't post on a site that shares experiences, knowledge and ideas across the world, and bridges all languages!!! :nono: To put a point in on this thread :multi ground plugs were designed for longevity ! If someone in their mind likes em I myself have no problem with that and some stated dino test with no variables or strict perimeters or multiple tests with real world atmospheres on someones engine somewhere in the world means nothing to me :smash:

Its Un Knowledgeable people that don't trust their own statements that tell people no questions, no debate !!!!!!

I and many on here index their plugs !! You cant do that with multi ground plugs The grounds block the initial flame ! . That would change all the tests result including the lawnmower !! Go cart and generator, So would the change in daily temp rise and fall or wind, humidity, especially on air cooled engines in a garage or field in a non controlled test!!! Not even a plug reading!!!

Jester



JESTER

 

SIGH.
I'm asking for nothing more than a part number. NOTHING MORE.
If I'd want a debate or a discussion I'd just read one of the other bazillion threads on here.
So Far I'm still waiting for an answer to the actual question instead of what one thinks the question is. Would be nice if YOU, you know, the most knowledgable of them all, would answer it.

 

Probably the only way you are going to find a cross fit is to decode the plug part numbers to determine thread size, reach, seat style, and heat range and cross it over to a commonly used conventional plug based off those numbers.

Just like you'd have to do if crossing an ACDelco over to a Champion or NGK, without a quick cross-over chart.

Whether you can find that info for the gimmick plugs is another question, I don't know the answer.

I did find a couple easy cross-over, for the ACDelco R45TS or R44TS, which crosses to the NGK 5 and 6 in heat range....the E3 plug number is E3.42. 14mm thread size, .460" reach, tapered seat Diamond-FIRE fixed gap plug.

Bosch has a Platinum+2, two ground electrode plug for that same application, #4302 which is heat range between 6 and 7 on NGK numbers

I got tired of trying to sort through Bosch wacky number scheme and couldn't find any crossover for their Platinum +3 or+4 types.

 

that 4302 plug translates to a bosch HGR9BDP, a 9 is equivalent to a NGK 4 afaik. Or did they change heat grades for american plugs too?
Same for the +4 plugs they have. I searched my old books and found HR91GX, wich fits, but probably is too hot.

 

R44TS, indexed.

 

I used to “side gap” my single ground spark plugs. It seemed to let the motor run more smooth. I quit doing it because it was not worth the trouble.

To do that you straighten out the ground electrode and cut or grind off about .050” from the end of the projected tip of the ground electrode and then bend it back into positional the side of the center electrode. . The gap remains at .035” but from the side of the center electrode.

It is common knowledge that multiple electrodes merely shrouds the spark energy. The spark plug gap should be towards the intake valve. You can purchase a kit of specially made spark plug washers to position the gap properly.

Multiple electrodes is another example of “More’s Law”. Which states, “if one is good, more is better”

 

I do the same on some of our engines, helps the idle a bunch. I've gotten really good at trimming the side electrode off with a hand held cutoff wheel tool. Clean up the cut a touch with a file and set the space gap - I normally run about .028 - .030 with them cut.