"Once the flame is lit it really would not matter if you put more sparks behind it."
- Not correct. If the intial spark does not achieve complete burn behind the flame front, then another spark could well help.

The bottom line on all this is that no one really knows the bottom line. This thread consists of opinions unsupported by data. Some have more knowldege than others but nobody has done the calculations -- have you? And I feel absolutely certain tha nobody has used a quartz window test setup to check those calculations.

Finally, I note that Steve Wiener (Rennsport) advocates the msd units and so do other race engine builders. They are neither scientists nor engineers specializing in combustion chamber evaluations, but they do have a lot of experience -- and that was gained with highly tuned engines. If I had a stock unit and needed to rebuild it, I would do that. If I had to buy new, I'd buy a msd. If my engine modifier gave me a msd, I'd use it (the latter is what I did).

JMO
A Properly Running Engine would not need more sparks particularly if it is a stock motor that is not high compression.

None of the boxes give additional sparks above 3000 rpm. One good spark is all that is required. Once the flame front starts it is going.

More sparks behind the flame that is already lit does not matter. If it did then the MSD and all the other boxes that only give multiple sparks below 3000 rpm would experience a power loss from 3000 rpm up......I have not noticed a power drop. I thought that this article summed it up well.

http://www.carcraft.com/techarticles/56400/

If there was a magical box that gave big hp and tq numbers they would be on every car made. MSD says high voltage is the key where Crane says that current holds the key. pick the one that you want.

BTW clean install Fred It looks good

H20911 -- You need to back up your opinons with something - anything. Remember power is not the only figure of merit in an engine. Emissions, mileage, reliability, maintenance intervals, etc. etc. are all important.

BTW, some of use have non-stock engines with pretty high comp. ratios.