Spark Plug Tech

Discussion in 'PSI Superchargers Tech Questions' started by Brownman, Nov 13, 2003.

  1. Brownman

    Brownman New Member

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    Hemi KB stage 15 with AJ heads..1471 screw charger running on alky. TAFC. Questions are...... How many runs on one set of plugs. Can they be blasted and re-used and what brand works best with this set up.......Oh and Gap? Have gotten many different answers here at a local track in the East. [​IMG]
    Thanks for the help!
     
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  2. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    first question is what is a 1471 screw charger. you either have a roots or a screw blower.

    i dont know much about roots tuneups, but you 'can' get 2-3 runs out of a plug. i wouldn't recommend it for a few reasons:

    1. plug is the best indicator of what 'really' happened in the combustion chamber. pyrometers may lie, plugs dont. when you start getting close on your fuel system and you reuse plugs....how much cad did it burn last time, or is it just burning more this time because the last run started to burn....

    2. i've seen bad spark plugs hydraulic motors. if the cylinder goes dead, all that fuel has to go somewhere. if it don't make it out the exaust valve..... you'll be wishing you had put new plugs in it.

    I would recommend NGK 6061-9 or -10's. start out around .016 gap and experiment from there.
     
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  3. Brownman

    Brownman New Member

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    Will: Thanks for the input. The common sense approach in the cost of the plug vs the cost of the engine says it all. Just for the record...its a screw blower. WE are just assemblying the flopper and have gotten some good information from the gang at your site. Will be out this coming season and hope to get a chance to say HI!
     
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  4. Will Hanna

    Will Hanna We put the 'inside' in Top Alcohol
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    also, while on the subject of bad plugs...

    it has been a common practice of most to warm the car up with the 'warm up' plugs...the ones from the last run, then put new in for the run. however, many of the top teams, myself included are putting the new plugs in for the warmup. what that does is tell you if you have a bad new plug. alot easier to fix in the warmup, then realizing it on the starting line.
     
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  5. Randy G.

    Randy G. Top Alcohol

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    Austin's lost a round of racing because they used warmup plugs and not the new run plugs. DT used to do the same thing until I pointed out the potential for disaster.

    BTW, I like N57DR Champions, myself.
     
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  6. Bob Meyer

    Bob Meyer Comp Eliminator

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    Randy; I know I'm just a welder, but you know I'm loaded with stories, so it might be to your benefit to call me on this one!

    Bob
     
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  7. Randy G.

    Randy G. Top Alcohol

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    This isn't related to one of those "Bob Meyer cars always shake" stories, is it? [​IMG]

    I'll call you.
     
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