Looking to change plugs but would like to stick with Champions; has anyone figured out if Champion makes an iridium plug to fit the Disco IIs?

 

Go Nuts....


Champion 9201 >> http://www.summitracing.com/parts/cpn-9201


NGK 3764 >> http://www.summitracing.com/parts/ngk-3764


AND on and on....

 

I know the Bosch catalog calls out a 9652, which crosses over to the Champion 9201. Both of these use the smaller hex (16 mm). The Champion 9804 seems identical in all dimensions to the OE (RN11YCC) Champion Copper Core plug, but is it the proper heat range? In the E3 conversion chart, the RN11YC and the Champion 9804 call out for the same E3 plug (E3.46).

Is the Champion 9804 an acceptable iridium replacement? I tried to ask Federal-Mogul (Champion's parent company), but all you get there is a tech service rep. that refers to their online data. Hell, they can't even give you an aftermarket cross to the factory plug number!

 

"For the RN12YC, the Iridium equivalent is a 9201, for a RN11YC the Iridium equivalent is a 9007 and for the RN11YC4, the Iridium equivalent is a 9804 (same as 9007, but has a larger gap)."

-The Federal-Mogul Product Support Team

Keep in mind, the 9201 and 9007 both have the smaller 16mm (5/8") hex size, just like the 7070 double platinum replacement. The 9804 has a 21mm (13/16") hex size.

 

so whatcha going with?

 

I pulled the plugs in the Disco; it has the Champion Double Platinums in there (7070 or RC11PYPB4), but unsure if they were ever replaced (82k miles). It did have the wires replaced (blue STIs). I'm now hearing the DIs used the RN11YCC (Double Copper Core) and the DIIs used the RC11PYPB4 from the factory.

Can anyone confirm?

Here are the actual Champion numbers for each plug suggested:

9007 - RN10WYPB5
9201 - RC12WYPB4
9804 - RN8WYPB3

If, indeed, the DIIs came with the RC11PYPB4, I'm thinking the 9201 is the closest (slightly higher heat range) than either of the other two, and it is in stock at my local NAPA. The 9804 appears to be a closer match to the RN11YCC, but it looks like it's a colder plug than the OE and more suited to the 3.9L used in the DI.

 

Why? Why not just go with the Champions specified for your Discovery (7070s aka RC11PYPB4 for the 4.0 engine and RN11YCC for the 4.6)?

Before I got my head back into wrenching and started taking care of my Rover myself the geniuses at a local independent shop put in fancy new super duper plugs. They lasted a year and 10K miles. Put in the 7070s and they're running strong 40,000 miles later.

 

E-3's are good plugs

 

I got some Bosch Platinum's (not the +4's) from Amazon for something like 29 cents each after rebate and they are working great.

 

Champion® Iridium

Looking for greater durability/longevity. I have 7070s in there now and some of the electrodes are eroded down to the insulators.