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308 single dist. spark plugs

Discussion in 'Technical Q&A' started by Doug, Mar 17, 2004.

  1. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
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    Doug
    I will probably be picking up a 308GT4 this weekend that has the single dist. electronic conversion and driving it home. I want to put in new plugs before the drive. What plugs and what gap is reccommended for a carbed car with the conversion?
     
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  3. Nuvolari

    Nuvolari F1 Veteran
    Sponsor Owner

    Sep 3, 2002
    5,694
    Toronto / SoCal
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    Rob C.
    While I cannot offer you the answer you are aftr, please list if it is an electronic or mechanical distributor. I believe that it makes a difference in plug choice.
     
  4. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
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    Doug
    Electronic dist.
     
  5. Dave

    Dave F1 Rookie

    Apr 15, 2001
    2,722
    Little Rock
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    David Jones
    Is there something wrong with the plugs that are in the car now?
    Just wondering why you would want to change them if the car is running right.
     
  6. Steve Magnusson

    Steve Magnusson Two Time F1 World Champ
    Lifetime Rossa

    Jan 11, 2001
    20,449
    Texas
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    Steve Magnusson
    Doug -- go to the old site and do a search on:

    NGK spark plugs (AND mode, parts-of-words)

    for previous discussions. My preference is an exotic-NGK (at the right price), but don't weigh that as more than a single vote.

    My recollection is the stockish 308 carbed gap is .024"-.027" (ignoring the lowish 0.4 mm in the 308GT4 WSM) and others have reported good results with ~.030" when using electronic set-ups -- but it's YOUR homework to read the threads ;).
     
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  8. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
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    Doug
    Dave,
    I drove the car and it runs a bit rich. The car has not been driven too much for extended periods(only 4000 miles in the past 8 years). I figure fresh plugs with a 100 mile trip will give me a more accurate plug reading on how the car is doing. I am not sure how old the current plugs are or if they are even gapped correctly.
    Steve
    I have researched the old archives but was wondering if there is any new consensus from owners that have been running the set up for a while.
     
  9. yelcab

    yelcab F1 World Champ
    Consultant

    Nov 29, 2001
    10,706
    San Carlos, CA
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    Mitchell Le
    NGK BP5ES (if my memory serves)
     
  10. chrismorse

    chrismorse Formula 3

    Feb 16, 2004
    2,149
    way north california
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    chris morse
    Doug,

    Two weeks ago I picked up a 77 GTB with 22k on the clock. The PO's mechanic said the air cleaner hac been blown out with compressed air. It ran well on the test drive, a bit sluggish at very low rpm but ok.
    On my 600 mile drive home, I was getting about 12 mpg on the freeway, drivingup the coast and being good, (70 mph).
    But, as i got into traffic -stop and go, it started to load up and die, this was a major pita in downtown san francisco and santa rosa.
    to the point - When i got home, i pulled the air cleaner assemply looking for the source of the gas smell i was getting and found that the air cleaner was kinda plugged up. I've driven it a bit without the air cleaner and the car runs better, no loading up or dieing. I know it is sinfull to drive without the ac, so i am waiting for the K&N unit to arrive.
    BTW if you go to pull the lower portion of the air cleaner unit off the car for any reason, be very carefull that the small sleeves that fit over each carb top bolt don't come off the stud and drop into the air horn. I had particularly good karma that day and it fell into the valley not into the carb!!!
    BTW #2 If the car has sat for a long time and you are going to take a long drive or even a short one home, buy a fire extinguisher and check the old fuel lines in the engine compartment. Rubber bushings and hoses deteriorate with time.

    good luck,
    chris
     
  11. pma1010

    pma1010 F1 Rookie

    Jul 21, 2002
    2,559
    Chicago
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    Philip
    5s or 6s will work well. I have run NGK 6s for the last 2 years. No issues.

    My gap with Electromotive Ig. is 35 thou. For standard ignition, gap is smaller (24 - 27 I think) -- check the manual.

    Have fun with your new toy!
    Philip
     
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  13. thecarreaper

    thecarreaper F1 World Champ
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    Sep 30, 2003
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    I NEED A JOB
    hmmmmmmmmm there was a 308gt4 in KY that had been sitting that was for sale. wonder if its the same one. guy was building a house and put the car there to "store it" . cant remember price but the " i dunno" answer to the belts/tensioners/records convinced me to pass. i hope its not the same car and that its a short trip. old belts and fuel lines scare me. congrats to you though, best of luck. michael
     
  14. f355spider

    f355spider F1 World Champ
    Rossa Subscribed Owner

    May 29, 2001
    17,306
    USA
    NGK 6's seem to be the "standard" set up (BP6ES or BPR6ES, the later been the "resistor" variant). If you are still having plug fouling, then the NGK 5 is the way to go. Gap will probably be around .030 (smaller gap with the electronic ignition may cause a "miss" at least it did in my carb 308), but you may be able to go up to .034 or .035 as others have mentioned. I think I settled on .034. Once you figure out the proper heat range plug, THEN take 91TR's advice and go for the super duper NGK Iridiums or whatever. But until then, I would start with the cheap, standard NGK's that are only $2 each... :)

    BTW, check what heat range plug is already in there. If they are NGK 6's or equivalent, then go for the 5's.
     
  15. Dave

    Dave F1 Rookie

    Apr 15, 2001
    2,722
    Little Rock
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    David Jones
    While I find the NGK BPR6-EVX to be a nice choice.
    It is a bit harder to locate, and a little on the expensive side for just running down a lean/rich problem.

    I might suggest a little less expensive plug for your drive home tests.
    I have found that in normal street driving with a carb 308,
    going a step hotter seems to work well.
    Pick up a set of Champion 300, N9YC...
    On my 308 with electronic ignition and, if memory serves correctly,
    MSD Blaster II coil, I run about .036 gap.

    Good Luck with the car!
     
  16. Doug

    Doug Formula 3

    Nov 13, 2003
    1,467
    Louisville KY
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    Doug
    I purchased the car today and drove it home. Michael, it was not the "beater" that you are referring to. I am the one that spoke to you about that car after I had seen it and decided to pass. This one is much nicer and the 100 mile drive was great. Carbs are a little fussy and I posted a thread with questions if anyone can help. I put in new Champions as suggested for the ride home and my carb problems are described in another thread.
    Having owned a 512bb abd a 308 QV previously, I was amazed how comfortable the car was. The first gear position doesn't jam your leg like the boxer and 308 QV. The car hit 125mph with no problem and felt very smooth. It should prove to be a fun toy.
    First issue, the carbs.
    Then onto the AC(compressor has been removed but I have it). I will probably upgrade to a Sanden unit.
    I am sure I will have many questions for you GT4 abd other 308 owners over the next few weeks.
     

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