Why Resistor Spark Plugs?

[rockerarm]

Hey all. I have a question as to why the common Bosch and NGK spark plugs are now only offered with a resistor, with a corresponding increase in cost. Thanks in advance, Bill.

[Mal evolent]

radio noise suppression. non resistor plugs interfere with other car radios.
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73 Beetle Baja, Ghia front brakes, Type 3 rear brakes, 2220 ( 94 X 80 ), Weber Progressive, Bosch SVDA, '97 Mustang seats

Baja Bugs for Volkswagen Virgins: Index

[borninabus]

NGK still makes non-resistors.
BP6HS for T1 & BP6ET for T4 is what i use.
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88 Van WBX, A/T - 13 JSW TDI 6M/T - 2012 Touareg TDI Sport

[Wildthings]

Most spark ignition engines require resister plugs so that is what the manufacturers supply. There is not much of a down side to using resister plugs, if you are worried about having too much resistance in the system then use a non resister rotor.

[chimneyfish]

Bosch still make them, I use W8CC, the hotter ones, which are fine for the climate here in the UK, all the following links are non-resistor:

Bosch W7CC: http://www.gsparkplug.com/shop/bosch-w7cc.html

Bosch W8CC: http://www.gsparkplug.com/shop/bosch-w8cc.html

NGK B6ES: http://www.gsparkplug.com/shop/ngk-b6es.html

German Supply sell the triple ground NGK BP6ET, never used them myself but from what I have heard and read a lot of people people seem to swear they are the best for the Type 2:

http://www.germansupply.com/home/customer/product.php?productid=16482&cat=&page=1
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1965 Type 1 Deluxe (1200cc)
1976 Type 2 T2b Microbus L (1800cc Type 4)
Previously...
1972 T2 Camper (Devon), 1988 Golf, 1972 Type 1, 1984 Polo, 1972 T2 Camper (Danbury)

[SGKent]

it suppresses radio wave generation. http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/faqresistor.asp

No biggee. If you are complaining about the additional cost of a few pennies, wait until you see what a glass of water costs by 2030.

[chimneyfish]

Was just now reading the Bosch/NGK plug chart at 1.45 on this Ratwell page (I'm on dual Solex carbs, he also gives plug codes recommended for L-Jet in the chart):

http://www.ratwell.com/technical/FAQ/FAQContent.html

Just for fun I'm now thinking of swapping my Bosch W8CC to NGK B5ES and see if it positively effects the running.

However, further to my linking to the three electrode BP6ET plug above, from what Ratwell says, the three electrode plugs don't seem to bring anything to the party! Anyone agree / disagree?

(like the oil sticky in the Performance - Engines/Transmissions forum, I'm suspecting choice of spark plugs are a rather subjective subject).

Also, in my Type 4 I'm running the restricted RPM's rotor in the distributor, but if someone was running the non-resistor rotor, would they be better off using the resistor plugs? (I don't mean as to limit RPMs, I mean to help with radio interference suppression).
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1965 Type 1 Deluxe (1200cc)
1976 Type 2 T2b Microbus L (1800cc Type 4)
Previously...
1972 T2 Camper (Devon), 1988 Golf, 1972 Type 1, 1984 Polo, 1972 T2 Camper (Danbury)

[busdaddy]

[WestyPop]

IMO... screw resistor plugs & resistor wires... go to monel wires. Haven't found how long they last, yet; they've only got around 125K miles so far. Seem to inhibit the RFI even better than did the German Bosch carbon wick wires with resistor ends. (W8AC plugs, gapped @.045", last 50-70K)

The monels hold up fine to the hotter sparks the Westy's capacitive discharge ignition system throws out. Once I saw that my V8 with a CD system would trash the carbon wick coil-to-distributor center wire in about 20-25K miles, I figured the Westy's 4-banger center wire was probably waiting to puke at about 40-50K miles. Didn't wait; changed to monel & they're still fine. OK, they're not OG... Waaah.

Just my 2 cents worth.
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Never underestimate the power of stupid people in large groups.
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J.R.
68 Westy
(+ others)

[chimneyfish]

[busdaddy]

There's all sorts of "reasons" why some carmakers use resistor plugs from radio or computer interference to length of wire effecting timing unless the resistor is at the plug. VW put the resistance in the rotor and wire ends and originally used solid wire so there was no need for resistor plugs. Some say too much resistance isn't good, others think it's fine, part of it depends on the health of your ignition system.

Here's how to ditch the resistor built into the rotor: http://www.huelsmann.us/bugman/RotorTech.html

Chimneyfish you are correct about the rev limiters, a spring loaded weight moves outwards at speed and grounds the spark out at the predetermined speed. Both solid and rev limiter rotors have a resistor, look for the epoxied area.
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[archemitis]

The real reason is to not send interference to any other electronics on the car(not so concerned with radios). If you have an electronic ignition non resistor plugs, and even solid core wires can make an Electronic Ignition malfunction.
If you have points and no radio, you would probably be fine without them.

http://www.championsparkplugs.com/glossary/8/spark-plug/R

People do strange things with spark plugs. Example, "I have a low compression engine that burns oil, and fouls spark plugs... I'll just run a hotter one.... "

[Chris_914]

[Wildthings]

[busdaddy]

[Chris_914]

[udidwht]

[69rulz]

When your radio is on a static channel and your have non resistor plugs, rev your engine, then radio goes nuts with loud static, white noise
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