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Join Date: Jan 2001
Posts: 696
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Can the gap for '87 sparkplugs' be increased beyond 0.28" for better performance?
Why is the gap spec. for '87 sparkplugs' only 0.28"? Can't the system put out enough to sustain a larger gap? What needs to be changed to increase the gap? I don't really want to go the MSD route, won't a higher performance coil work? Just doesn't make sense, a 60's Chevy with cheap factory components can easily handle 0.35" gap. Why is the Porsche ignition system so weak?
Last edited by movin; 03-18-2006 at 05:52 AM.. |
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03-17-2006, 09:17 PM
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Thought I would share what I found.
Opening The Plug Gap: On weaker or stock ignitions, opening up the gap CAN increase the spark kernel size, thereby creating a more efficient burn. The problem lies in that any added gap creates more strain on the other ignition parts. Coils may not have enough stored energy to fire, or in the least case, not enough energy to cross the gap, creating a miss-fire. Plug wires will break down due to the added resistance as the spark tries to reach ground. Rotor and Cap, as well as points (if you still have an interest in prehistoric ignitions), and the carbon bushing in the center of the distributor cap will show early failures. All of this is because the greater the gap and the higher the voltage requirement to jump the gap. Do not forget the gap between the rotor arm to the distributor cap too. A high performance rotor is a bit longer at the tip, allowing less spark loss or chance of spark scatter in the cap as the spark attempts to jump the plug gap. |
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03-18-2006, 05:57 AM
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How about changing the stock coil to a Nology PFC-M70 high output coil? Would that allow increasing that gap?
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03-18-2006, 09:21 AM
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Join Date: Dec 1999
Location: Novato, CA
Posts: 4,740
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The reason the plug gaps are limited to .028" is because the copper core Beru ignition wires are not capable of larger gaps without shorting out. That's why MSD warns against using copper core wires.
Personally, I have no problems running my plug gaps to .060" using conventional carbon core wires with the stock DME ignition system which is every bit as capable as your basic HEI ignition system. Cheers, Joe 74 w/ 86 3.2 |
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03-18-2006, 06:28 PM
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Join Date: Feb 2004
Location: Long Island, N.Y.
Posts: 1,798
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Are Magencor 8.5mm carbon core wires?
j.p. |
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03-18-2006, 06:36 PM
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