Reply to "DURASPARK DIZZY RPM LIMITS??"

First, I only ran (past tense) the Duraspark II.
At times with a vacuum advance, at times without it.
It was not a dependability issue, just a tinkering issue of making the engine run better across the rpm spectrum.

I don't recall ever having issues with it, just looking for a way to fire the spark plugs in a way to keep them clean at all rpm.

This was both with a Holley 4779 carb and the Weber IDA's.

The Holley was the problem child, not the Webers.


RPM consistency is much better with the Duraspark without a vacuum advance.

I will agree with George in that my rpm limit was about 7,200 rpm.



All the advance considerations of a dual point Ford distributor are going to be the same as with the Duraspark since they use the same internal mechanisms.

The "rap" on using the vacuum advance in virtually any distributor is that the vacuum mechanism tends to create a "advance plate" that starts to bounce at around 6,000 rpm thus causing "instantaneous" timing variations.

It is a fairly simple procedure to remove and lock out the vacuum advance from any Ford derived distributor and many race teams/cars do this as a matter of fact.


Two Ford dual point distributors had no provision for vacuum advance in the distributor castings that I can think of. The 427 and the 289hp. Even the Boss 302 and the Boss 351 dual points were made to use a vacuum advance as well.



The Duraspark is a very dependable system but in my view is intended solely to eliminate the points from the "equation".

With an engineering criteria of lowering emissions, consistency of the ignition system was a prerequisite which the Duraspark delivers.

An additional thought of mine in I vs. II, is justification that it is available generically anywhere in the country at virtually any auto parts store. I am pretty sure that is true of the II but not convinced that is true of the I considering that primarily the I was a "California only" item?



Another thought is that the Duraspark system is limited to using a "coil in a can" whereas something like the Pantera-Electronics "engine-controller" uses your choice of an electronic coil, so in that case the Ford is at a disadvantage.

However you are not going to get another P-E unit at any parts store so I suppose that is a consideration as well?



In ANY case all of the Panteras need a very serious ignition upgrade and the Duraspark is a great way to go.

Rocky. Don't rev this thing to 7,200 backing it out of the garage, ok?