Dual point dwell

[Brandon]

Out of my continued curiosity, I ran across this thread:
https://www.saac.com/forum/index.php?topic=28836.0

So is the correct part C5AE (traditional) or C5AF (transistorized)? The thread I referenced above seems to indicate C5AF, and if it were that, the manual would be correct vis a vis Tim's comments on 22-24.

[TLea]

Just to circle back I just broke in 67 engine in run stand. Set each set of points @ .020 and dwell was right at 33

[Brandon]

Interesting, I wonder why my gap is so much smaller to get to 33.

[Road Reptile]

Hi to all,
As mentioned dwell is affected  by a  few factors, the first is distributor bushing clearance.If wear is excessive points are very erratic as engine speed  changes.Second is rubbing block condition,which I suspect is what explains the numbers you are seeing.
Easy way to  prove this would be try a different brand or compare with a set of OEM points.This is a great example of how engine management has progressed over the years     
Now the crank triggered/camshaft monitored style is very precise regardless of miles
Or hours of use. Best way to see if your parts are still good  is test with a syncrograph machine....something few people see anymore. Hope this helps R.R.

[FL SAAC]

Yall still "dwelling" on this subject

One word

Pertronix

[shelbydoug]

It was a simple question and the simple answer is that it just isn't that important that you have the maximum dwell.

All that is doing is giving the coil the maximum amount of time to build a charge at very high engine rpm.


The thing that you feel immediately with the  Petronix is that the engine seems more powerful but that is simply more built in dwell at idle and seriously is difficult to measure on a dyno.
It might amount to a few ft-lbs of torque on the street.

The major benefit would be that the plugs, particularly the 32 series would run cleaner, longer but the negative is that you will be replacing them because you are burning through the tips faster, rather then replacing them because they are fouling.

The bottom line is that you are still replacing them, so with points the simplest, which often is the best for a different reason, is to just set the new points by gap and forget them.


Also consider that later CJ 428'x would probably run BF32's whereas the 67 GT500 runs BF42's. So speculating why you might consider the interaction of the dual points with more dwell and the tendency of the 67 with the automatic transmissions to foul spark plugs prematurely?

You should remember though that the points for the duel points run higher tension and wear out the rubbing blocks faster so the points are closing down sooner then the single point distributors are. That means servicing the points sooner then the 25,000 to 30,000 mile servicing of the single point distributor.


So if all of this is no doubt spinning your head? Well, "Mr.Andersen, welcome to the Matrix", the program is running and be aware of where the phone is located?