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BOSCH Platinum + Spark Plugs

The original platinum spark plugs are the model F8DPER, single pole with a resistor

of 1380 Ohms. The newly recommended replacement from Bosch USA is the

Platinum + 4 pole 4418.

Interestingly, measuring the resistance, not showing any continuity

between the center electrode and rear connector pole.

The BOSH USA tech support is not helpful with technical questions.

It looks like the center electrode has an internal secondary gap.

The recommendation from a Mercedes mechanic with years of

experience is, that I should not use the 4-pole platinum sparkplugs; it will cause spurious engine problems.

A mechanic, member of the Mercedes racecar teams, told me that they using NGK spark plugs.

Any opinions?

Reply to
P M
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Bosch Platinum plus with center pole and two grounds, both pre gaped, work very well in my 24v straight six.

Reply to
T.G. Lambach

Bosch Super Copper core ..

Reply to
AJDalton7

If you are not measuring any continuity, then the spark plug is bad... it has been dropped and cracked the electrode internally.

I don't recommend any platinum plugs on any car.

Reply to
Tiger

Thanks Tiger, but I opened a brand new 4 pack and non of them has continuity. Tha BOSCH "Contact Us" support not able to answer engineering related questions.

Reply to
P M

Wow, I opened a new box they have 1090 Ohms. That is a bad QA control.

Reply to
P M

I've been using Bosch Platinum +4 plugs in my 24 valve straight 6 cylinder Mercedes. I called Bosch tech support after being warned not to use them on this newsgroup. Bosch claims that their Platinum +4 plug has been field tested in the Mercedes 24 valve straight six engine. I think the "problem" is that the 320 engine uses one ignition coil for two cylinders. The polarity is different for different plugs but I've never had a problem with the +4 plugs. Bosch recommends against using their standard Platinum plug in this engine.

Reply to
VCopelan
104 eng runs best on F8DC4 Supers .. period.. Plats ruin the coils on Waste Spark systems
Reply to
AJDalton7

The theory is this... The reason why Platinum works very nice is because majority of cars have weak ignition coil... Platinum plugs takes alot less effort to ignite than regular plugs. Therefore, less work for ignition system... the better it runs...

MB coil is not too bad. Anyway, less effort to ignite also means weaker spark.... Weaker spark means less power... It also mean smoother engine... but less power.

So by using normal copper plugs... it work the igniton coil harder to produce more powerful spark. which means more power

Reply to
Tiger

Whose theory is this? Yours?

Reply to
Chas Hurst

Jacob Electronic... maker of high performance ignition system.

Reply to
Tiger

Don't you think the larger gap on the plus4 plugs would more than compensate for the lower resistance?

Reply to
Bernard Farquart

It would make the resistance higher but not as much as copper plugs... the key to Platinum's success for easier ignition is super thin pointy electrode... you need platinum for durability when using this method...

I have seen a Mallory Ignition demonstration... 100,000 Volt ignition coil... have two pointy electrode about 1.25" apart... and the guy put in between 1/2" layer of business cards in between and spun the distributor... spark flew across that gap and business cards.

What I am saying is that by putting a super thin pointy electrode, spark is easily attained...

Copper plug got a wide electrode but spark is generated by the pointy edge... when it wears our... rounds out... the ignition work harder to produce that spark.

Reply to
Tiger

The reason for Copper on 104 Waste spark is cuz the coil feeds two plugs in SERIES. That results in the second plug firing from ground to the electrode. This , coupled with the wide gap [ sum of both plugs] has shown copper non resistors to work best. Don't forget . on all 104 HFR didtributorless ingitions , the connector under each coil IS the resistor... So, forget about resistor plugs.. Put it on a scope and you will see...

Reply to
AJDalton7

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