Sorry Matt
I got the part numbers the wrong way round
Regards
Ian L
What spark plugs are you guys using?
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Dr. Ian Levy
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I'll put in my 2 cents worth on the spark plug recommendations. There seems to be a concensus on the NGK BP6ES. This is a good heat range for the cars we are speaking of, I personally use Bosch W7DC with resistor connectors.
The original heat range recommendations in the owners manual are too cold for driving in this country, the Europeans tend to drive much harder than we do.
I would strongly recommend that you not use 2 heat ranges hotter as one writer mentions unless you want a hole in a piston. I've read similar recommendations about using 2 heat ranges hotter and even stating that heat range is irrelevant in a Ferrari enthusiast magazine. This is dangerous ground.
If you need to use a hotter plug because of fouling, you need to look at state of engine tune and if you are burning oil. Both these conditions require maintenance and not hotter plugs.
Jim Burnett
The original heat range recommendations in the owners manual are too cold for driving in this country, the Europeans tend to drive much harder than we do.
I would strongly recommend that you not use 2 heat ranges hotter as one writer mentions unless you want a hole in a piston. I've read similar recommendations about using 2 heat ranges hotter and even stating that heat range is irrelevant in a Ferrari enthusiast magazine. This is dangerous ground.
If you need to use a hotter plug because of fouling, you need to look at state of engine tune and if you are burning oil. Both these conditions require maintenance and not hotter plugs.
Jim Burnett
Jim,
You are completely correct in warning to not use too hot of a spark plug.
Is a W7DC hotter than a BP6ES?
It's hard to tell because you can't compare heat range numbers between NGK and Bosch. They're like apples and oranges. An NGK 6 may or may not have anything in common with a Bosch 6.
Also, the heat scales are complete opposites. For NGK, a 5 is a hotter than a 6, and for Bosch it's a step colder. On the Bosch scale 7 is actually hotter than the 6, while it would be cooler on the NGK scale. Stepping from one manuafacturer to another confuses me.
What other Bosch plugs have you used, and how did you decide on the W7DC?
--Matt
You are completely correct in warning to not use too hot of a spark plug.
Is a W7DC hotter than a BP6ES?
It's hard to tell because you can't compare heat range numbers between NGK and Bosch. They're like apples and oranges. An NGK 6 may or may not have anything in common with a Bosch 6.
Also, the heat scales are complete opposites. For NGK, a 5 is a hotter than a 6, and for Bosch it's a step colder. On the Bosch scale 7 is actually hotter than the 6, while it would be cooler on the NGK scale. Stepping from one manuafacturer to another confuses me.
What other Bosch plugs have you used, and how did you decide on the W7DC?
--Matt
Matt,
A Bosch W7DC and an NGK BP6ES are nearly identical heat ranges and both are copper core. The reason I use resistor connectors is because I converted the ignition system to electronic.
The best way to decide on a plug application is to use that manufacturers application catalogue. Unfortunately most plug manufacturers no longer list cars as old as ours. I don't recommend using a cross reference chart to do application work, it is just a reference. All plugs will perform slightly differently even for equivalent heat ranges from brand to brand. Each manufacturer will have a cross reference chart at the back of their catalogue.
I use Bosch plugs because I am thoroughly familiar with them, having worked for Bosch the last 26 years.
Jim B.
A Bosch W7DC and an NGK BP6ES are nearly identical heat ranges and both are copper core. The reason I use resistor connectors is because I converted the ignition system to electronic.
The best way to decide on a plug application is to use that manufacturers application catalogue. Unfortunately most plug manufacturers no longer list cars as old as ours. I don't recommend using a cross reference chart to do application work, it is just a reference. All plugs will perform slightly differently even for equivalent heat ranges from brand to brand. Each manufacturer will have a cross reference chart at the back of their catalogue.
I use Bosch plugs because I am thoroughly familiar with them, having worked for Bosch the last 26 years.
Jim B.
I have had good luck with the Bosch WR8DP platinum plugs in 250, 275, and 330 engines. Reguardless of what brand of plug you use, always wipe some Neverseze compound on the threads, as the alloy heads are famous for corroding the plug in the threads, and trying to force them out may strip the threads. Jim Riff
Bosch does not recommend using antiseize compound on the threads. Antiseize will change your torque value and can give you a potential misfire. Bosch plugs are nickel plated and have rolled threads. Chances of taking the threads out when removing plugs are virtually nil.
I use W7DC in my 330. A 6 heat range is closer to the original recommendation. Using an 8 heat range is probably ok as long as you don't put a load on the engine. Hard driving with a heavy load may put you in the preignition range. Preignition will cause serious engine damage very quickly.
JimB
I use W7DC in my 330. A 6 heat range is closer to the original recommendation. Using an 8 heat range is probably ok as long as you don't put a load on the engine. Hard driving with a heavy load may put you in the preignition range. Preignition will cause serious engine damage very quickly.
JimB
