| Tbirdusa |
Sun Aug 17, 2008 12:23 pm |
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Bought the CB Mini D wedge port heads. Calls to use 12mm long reach plugs. Never had a set of heads for these plugs. What is a plug number to use for street driving?
2332
44's
125 cam
009 dist w/Pertronic
8.75:1 cr
Engine is brand new. |
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| The Noof |
Sun Aug 17, 2008 12:43 pm |
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| I run DR9EA NGk's, but it's a turbo.You can use 7's or 8's |
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| Tbirdusa |
Sun Aug 17, 2008 1:01 pm |
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| you run those to keep the heat down, right? |
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| Scott Novak |
Mon Aug 18, 2008 4:20 am |
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The Noof wrote: I run DR9EA NGk's, but it's a turbo.You can use 7's or 8's
Noof, do yourself a favor and pitch those spark power robbing resistor plugs in the trash and get a set of non-resistor NGK D9EA spark plugs instead. With a Turbo you want all of the spark power that you can get.
Tbirdusa wrote: you run those to keep the heat down, right?
You select the heat range of the spark plug so that the spark plug insulator around the tip of the center electrode it is just hot enough to keep clean.
Engine combinations vary dramatically and what works for your engine may not be right for the next person's engine. You need to some trial and error testing and do plug readings to determine if your heat range is correct.
It's always safer to start with a colder heat range spark plug. Assuming that your engine is in good condition, and your fuel mixture and ignition timing are correct, if your spark plug begins to foul, the heat range is too cold. Try one heat range hotter. If the plugs stay clan, you're golden
If you run a high energy electronic ignition system, you can usually use at least one heat range colder spark plug and still have the spark plug stay clean. Using a colder heat range spark plug reduces the possibility of pre-ignition and run on.
A higher compression engine is more likely to heat the spark plugs hotter, so it might be a good idea to start with a colder non-resistor spark plug such as an NGK D8EA. If the spark plug fouls, you can either install a high energy ignition system which will keep your spark plugs clean and improve your performance as well, or you can change to the next hotter heat range spark plug, which would be a D7EA. With a weak Bosch Blue ignition coil you may even need to go as hot as a D6EA. The D5EA is the stock heat range, and probably too hot for your higher compression ratio engine.
With a non-turbo application you might be able to use projected core spark plugs for improved performance. The numbers would be NGK DP5EA-9, DP6EA-9, DP7EA-9, DP8EA-9, DP7EA-9. The -9 indicates the spark plug gap that it comes with in mm.
Scott Novak |
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