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Which spark plug do your prefer?

Wrecked82

Delco rapidfires are now platinum.

Rockn-Roll

There's actually a new style that has 4 cathodes, plus a platinum core for the anode...now that might be ideal...of course I'd rather just use a hypergolic fuel like red fuming nitric acid and Hydrazine...but I believe the platinum core is more desireable over multiple cathodes.

Robert Holtman

I run Bosch platnum with 4 cathodes. They are called Bosch Platnum +4's (if I remember right). I like them. Don't know if they make a big difference though.

Vettesic

I hve Delco rapid fires also. The ad for them says...faster starting? The vette seem to run better with them. A bit expensive though. Good luck, L8TER, Paul.

Fevre

I run cheap ones to get the engine fired and bugs worked out then switch to better plug for the final fine tuning. I have run split fires, bosch platinum adn rapid fires and found not much difference. Actual not much diff between cheap champions and the rest but how wants to say they are running cheap plugs, doesn't sound :cool: . :)

dgruenke

A platinum plug is not designed to give more performance. A platinum plug is merely designed to last longer. The platinum electrode does not wear down or corrode like the standard copper cores do. Also, the multiple grounds (terminals) on a plug does not give any added performance. This is because the spark can only go to one ground at a time. Hence, there is still only one spark. The A/C Delco Rapidfire is what I run on mine. The idea behind these is that the electrode design itself will produce not more than one spark, but a larger, wider spark. Therefore, there is a higher chance of burning all the gas.
Hope you find one that you like.

81VETTOM

I use rapid fires in my truck, and both vets. Heck I'd put one in my mower if they made one. :yesnod:

ZD75blue

Hey this is personal expierence... Working at the church garage... we have this 80's v6 cavalier that was donated, it had the bosch platinums in it... they were to long, it didnt idle, ran rough etc... changed to some delco plugs.. smooth as butter, no idle probs...

I say stay away from the bosch, a friend said that in his service manual, said not platium plugs for the first 100k miles, makes me go? :crazy: wonder why? This was a tuarse or whatever.. fords new whatcha call it econobox...

I'm running rapid fires in my 75, they are very nice, smoothed it out a little, only 25 miles or so on em tho...

kgraumann

I just put Delco Rapidfire in my ZZ4. The specs called for these as the other alternative, so I tried them.

I see no difference in performance, but it does start faster. Since my ZZ4 is still under warranty, I needed to stay with what GM called for.

:rolleyes:

79MakoL82

Absolutely agree. The multi terminal plugs are nothing but a gimmick although the platinum may help a plug last longer. The spark takes the path of least resistance, and that determines which terminal the spark jumps to. You only get one spark, and as long as that spark is strong enough, the vapor will burn. The only difference is if you were to get a MSD box that gave multiple sparks in succession, but still only one spark occurs at a time.

I run the Rapidfires. in the Vette. However, because of header clearance issues, I run Bosch platinums in my Z28. They are a shorter plug and make installation a little easier.

Black68Vette

I've got a Bosch Platinum in my edger.. damn thing ran like crap with the regular lawn mower plug after sitting for a while, looking in the toolbox was some used Bosch plats that have been in there forever (can't even remember what they were on). Dropped one in, damn edger fired right up and runs like a champ now...

garagedweller2

My dad's lancia fulvia (10:1 compression) ate single cathodes, needed multi-cathode + longer NGKs. 4 cathodes are not marketing gimmicks, they help. (occasionally) :)

79MakoL82

Well, my Z28 (10.5:1 compression) lives on singles and runs like a champ. I will admit that they are Bosch though (they are not platinum+4's), but only because I need header clearance and they are a shorter plug. A spark is a spark. Hotter/colder or plug length may make a difference, but 1, 2 or 4, you get one spark. That's a fact.

Rockn-Roll

Hmm, here's a technical perspective for multiple cathodes and platinum:

The reason there is any spark at all is because there are more electrons on one pole than the other. When the spark occurs then they both have the same electrical charge at the exact time that the spark occurs. Thus, the pole receiving the electrons (cathode/outside pole) will need to remove those electrons by disbursing them though the ground system (into the engine and off to the negative battery terminal). since this is happening at all eight cylinders the engine tends to have a lot of currents and eddies going through the block (which experts say may also tend to weaken the block) which restricts the flow of electrons. Thus, spark plugs that have more than one cathode will be better off because during high RPMs the last cathode that was fired may not have gotten rid of the last charge by the time it needs to fire again, but in a multi-cathode plug there will be other cathodes that have already removed the charge and are ready to accept another spark. Thus, the rapid fires, and especially the +4, assist in providing a cathode which is free of electrons and ready to accept a spark.

Platinum plugs are a different matter. The platinum is not there to prevent erosion, though it does do that too. Platinum is an explosive catalyst between Hydrogen and Oxygen to create water. If you have a room full of two parts hydrogen and one part oxygen and then throw some platinum into the room there will be a huge explosion and the room will then be full of water...H20 (and little bits of person if someone is in the room), and interestingly the platinum will be down at the bottom of the pool unchanged...well, maybe in a different shape and possibly in little bits spread out in the room, but nonetheless elemental platinum just the same. During incomplete combustion in an engine there is some unburnt fuel that includes some hydrogen which gets nudged around into other forms of hydrocarbons, but doesn't get burned, and also free oxygen which usually wind up forming carbon monoxide, or just O2. The platinum helps strip the hydrogen from the fuel and burns it with the free oxygen, thus resulting in more complete combustion.

These benefits usually aren't seen in a clean burning engine, but VERY noticeable if your air/fuel mixture is off, timing is off, or leaking rings, etc. when a hot spark and complete combustion are not occuring already.


[Modified by Rockn-Roll, 6:48 PM 4/13/2002]


[Modified by Rockn-Roll, 5:09 AM 4/14/2002]

vert2go89

I have run bosch plugs in several of my vehicles and found they fouled faster than good old champions.I've heard people say they wouldn't use champion in their lawn mower let alone their car but for me champs out performed the bosch.

retsbewt

Many of these answers are great but keep in mind, the AC Delco has a longer tip on the plug which reaches deeper into the cylinder which will help spark & fire the engine better. The AC Delco Rapid fire plug has a shaped side wire to direct the spark into the cylinder. The new AC Delco Platinum plug also now has these shaped side wires. If you were to go out and buy some AC Delco Rapid fire plugs you will get a rapid fire plug with platinum on the center wire and a touch on the side wire. We have learned that more platinum does not mean better. The only purpose for the Platinum is because GM went to AC Sparl Plug and told them they wanted a 100,000 mile plug. We added platinum and they got what they asked for. (the platinum does not perform any better but will last about twice as long) You can not buy a new style platinum plug for an engine that is very old. Some old engines have a flat engine seat & all the new platinum plugs have a tapered engine seat. Our Rapid fire plug comes with either. The garbage about the multiple tails on the side wire are just that. When Bosch was advertising that plug we sued them because you can only have one spark at a time & they were advertising you could recieve mulitple sparks. Let me know your engine size, year & and add ons you have & I will have one of my product engineers spec. out the right plug. I use the AC 2 Platinum rapid fire. I may be a little protective of AC Delco brand because I am the plant manager of the Flint Michigan plant that builds a variety of conventional, platinum & rapid fire plugs. Currently about 400,000 plugs a day, down from about 1.2 million a few years back.

Tim

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Wow...straight from the expert! I think the AC Rapid Fire #2 plug fits in my engine. And according to what youi're saying, this plug could last a 100,000 miles?

By the way, I pulled out a plug (AC R45TS), and it looked great! Only problem was that I broke the top half in two parts pulling it out. Replaced it and for now the regular AC's will just fine. :smash:

verskel

On normally aspirated engines (w/carb. vs. injection) - especially :chevy
AC Delco, Champion, etc. all have the 'proper' heat ranges.
Bosch doesn't match up with AC's - thus they could cause an older engine to run 'poorly'..... I've tried them but with no success.
AC's or equivalent are the way to go - stay away from 'import' parts :U

Fevre

Mine is running like a champ now and I have Boschs in it. I am interested in their long term characteristics. Some problems can be attributed to poor tuning. Sometimes expensive parts don't like things outside their operating range while some cheaper parts fundtion the same under wider range of conditions. The more expensive part will run bettter than the cheaper part in it's ideal operating range and the cheaper part works better outside that range. I bet plugs fall into this catagory.

Of course I could be way off but it does happen. Try slicks on a wet road to see what I mean.