is this true?

[astrochimp]

"Compression during the compression stroke of the engine can "blow out" the spark. So, yes, it has something to do with spark intensity. Of course, if you are having that problem, then your spark is not intense enough. I didn't mention this before because it was beyond the scope of the question."

 

can't say i've ever heard that can blow out the spark like a candle

[hamster]

My guess would be that depending on the compression ratio and the amount of fuel, it wouldn't literally "blow the spark out" but it would be that the spark would not be intense enough to ignite the higher fuel mixture under extreme compession?

 

Just a thought

 

Don

[wallaby]

The higher the pressures are in the cylinder when spark is triggered, the harder it is for the ignition to get the job done. How long does a spark last? If it happens at all, that's all you need. There isn't time for a spark to start and then be blown out. If the cylinder pressures are too high, the spark just won't happen. The electricity sent to fire the spark plug will find an easier path and go somewhere else instead. It may jump through the plug wire insulation and find a ground, or jump to another terminal inside the distributor cap, or jump through the rotor straight to the top of the distributor shaft.

Compare an HEI system with the older points-type, and you can see that the engineers were designing the HEI to combat these effects. The HEI uses a fatter plug wire because it has thicker insulation, The terminals on the distributor cap are further appart to prevent spark jumping to the wrong terminal, and the rotor is of different design in an effort to keep the spark away from the distributor shaft. Even the coil is different as it has no coil wire; that shortens the distance the spark has to travel, and it eliminates leaks from an extra length of wire and its connections.