Ignition Coil

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I was needed some opinions on ignition coils. Do stock coils provide enough juice for the spark plugs at high RPM's? Or just the right amount needed? Whats the average volts a stock coil gives for an ordinary 6cyl sedan. The most important question is how long do they last before they start to fail and not produce as much volts as before. Any major effects from a coil not providing as much volts as it should? Thanks

posted by  speedy266

All an ignition coil is is a transformer to step up 12 V to a higher voltage

This voltage varies from 15000-20000V on older cars with points type ignition systems to over 40,000V on late model cars using GM's HEI system or the DIS systems used by most manufacturers

Ignition coils typically last over 100K miles but do, like any other car part, fail which is why secondary ignition voltage is tested during a tune-up.

Many factors go into selection of secondary ignition voltage levels during engineering such as range of air-fuel ratios one expects to see, spark plug gap, etc. A stock coil will work under the conditions the engine was designed. If one is modifying the engine, the ignition system and ignition system control needs to be looked at.

Hope this helps

posted by  tbaxleyjr

Wow that helped alot thanks!!! I ordered a Accel Brute Thunder HEI Super Coil says its produces 48000volts. (Fits Buick V6 and V8, Oldsmobile V8, Pontiac V8 and 1981-91 Corvette. What i was wondering was the V6 is using the same coil as all the other V8's, wouldnt the V6 benefit the most and get the most volts cause it only has to distribute that high voltage to 6 cylinders? So like if there was a test done, a 4 cyl, 6, and 8. All have the same coil, same sparks, same wires, and same spark gap. Would the 4 cylinder have the greatest volts jumping the gap or would they be equal?

posted by  speedy266

As far as I know its not like there are 48k volts stored up a one time and then each spark plug gets a share of it when it is suppesed to fire. I belive that the computer decides which cylinder is supposed to fire when. It then directs the 12 volt supply to the right coil which then gets steped up to 48000 volts and then on to the spark plug. The number of times the computer has to do this whether four or eight should not make a difference in the final voltage in the secondary coil. If the ingniton is putting 12v throught the primary coil and the coil pack is working there should always be 48,000v in only one of the secondary coils and on its way to the plugs.

posted by  wizzyb82

The GN HEI system is a standard distributor which has a rotor which is indexed (points to cylinder 1 on the dist. cap) to the TDC position of the #1 cylinder @ the top of the compression stroke/beginning of the power stroke. The rotor makes the connection @ each individual cylinder's plug wire terminal in the dist. cap as the rotor rotates thus determine which cylinder fires.

There are other methods used such as waste spark distribution used now.

posted by  tbaxleyjr

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