Bosch W7DC equivalent

Discussion in 'Airheads' started by Tripletreat, Aug 1, 2021.

  1. Tripletreat

    Tripletreat Long timer

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    The spark plug charts at my local parts suppliers do not have a refrence for Bosch 7DC spark plugs. Some BMW speciality suppliers offer a resistor plug instead. What's one to do?
    #1
  2. akabeton

    akabeton Adventurer

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    Beru 14-7 DU
    or
    NGK BP5ES
    #2
  3. 190e

    190e Long timer

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    or Denso W20EP-U

    Spark Plug Heat Range Equivalents.jpg
    #3
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  4. bmwrench

    bmwrench Long timer Supporter

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    BMW still has thousands of non-resistor plugs in inventory. Unfortunately, they are not made in Germany, and thus I am concerned about quality.
    #4
  5. ccmickelson

    ccmickelson MonoMania Supporter

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    I have some Russian-made W7DC’s but haven’t used them so no idea of performance/quality. They look very similar to the original German one’s.
    8A9E9BEB-47A2-43E5-8CE0-D94570A758BB.jpeg
    My ST still has the original spec’d W7D plugs in it. I assume this plug was superseded by the W7DC? Not sure what the difference is if any. There’s a seller on eBay selling lots of ten NOS, made in Germany, for about $33 with shipping.
    https://www.ebay.com/itm/3040147267...gvINZ7YAB03rLpw4NlgZPz7uU7Wr5ZyBoCw5UQAvD_BwE
    #5
  6. Tripletreat

    Tripletreat Long timer

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    The local parts guy sold me NGK BPR6ES. Suspicious of the "R" in the #, I went to the NGK website. Man, that was a waste of time! I'm guessing the plugs I bought are resistor types. :-(
    I'm going to check out the eBay seller....
    #6
  7. 190e

    190e Long timer

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    C is for copper cored. They probably added the C to distinguish them from the precious metal types.

    Bosch.jpg
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  8. Plaka

    Plaka Brevis illi vita est

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    I only run resistor plugs from the flaps with non-resistor caps. I like being able to get a wide variety of plugs anywhere. I do check new plugs and make sure the are about 5k ohm and make sure my wires and caps are 0 ohms.
    #8
  9. Biloxi Joel

    Biloxi Joel n00b

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    NGK BP5ES available at Advance Auto for $2.80/each... work well in my 1975 R90/6.....
    #9
  10. ccmickelson

    ccmickelson MonoMania Supporter

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  11. bmwrench

    bmwrench Long timer Supporter

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    Most late Airheads ('77-'95) will fire a resistor plug even with resistor caps. However, I think that in the future, we'll be running low, or no, resistor caps and resistor plugs.
    #11
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  12. BJMoose

    BJMoose that trick never works Supporter

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    I bought a box too and really fast shipping, even out here in the sticks. Looks like I'm set for plugs for a while.
    #12
  13. Tripletreat

    Tripletreat Long timer

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    Have you verified that those are non-resistor spark plugs? The description doesn't seem to say one way or another.
    #13
  14. bmwrench

    bmwrench Long timer Supporter

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    When Bosch or NGK plugs are resistor type, they include the letter R in their part number, i.e. WR7DC
    #14
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  15. ccmickelson

    ccmickelson MonoMania Supporter

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    what wrench said, and yes, verified non-resistor by my multimeter.
    #15
  16. Tripletreat

    Tripletreat Long timer

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    I bought some genuine Bosch plugs from the eBay seller in Washington state. Very satisfied with that transaction!
    The local BMW dealer just wasted my time.
    #16
  17. bmwrench

    bmwrench Long timer Supporter

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    That's just weird. All he had to do was to look up the part number and order them, although they should have had some in stock.
    #17