Re: IML: dual point distributor questions

["Stevan Miner" <miner@xxxxxxxxxxx>]

Hi Dan,

The main reason for dual points is to increase dwell time of the coil which in turn will create a hotter spark from the coil when they open. As far as adjusting the points, if I remember correctly Mallory didn't have an external adjustment like Accel had on their dual point distributors. You  can adjust them with the engine off by running each set up on to the high point of one of the lobes on the distributor shaft and using a feeler gauge to adjust them. I always preferred to set the dwell on them by blocking off one set with a matchbook cover and cranking the engine over to adjust them individually to their proper dwell specs. If it was my car, I would toss the distributor over my left shoulder and install a Chrysler electronic ignition kit and forget about points forever. Unless the engine is modified, it will only use as much spark as it needs to fire the plugs and a dual point distributor is really unnecessary.

Stevan Miner

Miner Auto Service

Winnebago MN

----- Original Message -----

From: therichardsonfamily@xxxxxxxxxxx

To: IML

Sent: Monday, November 27, 2006 12:38 PM

Subject: IML: dual point distributor questions

Hello everyone:

 

I have a '67 440cid Imperial motor that has a Mallory Dual Point (#ZC365HP) distributor on it.

 

Question #1 - exactly how does a dual point work?  Does one set of points deliver spark to 4 cylinders, and the other set to the other 4?  What is the high performance advantage to a dual point?

 

#2 - I don't see a way to adjust the dwell when the car is running - is that correct?  I check the dwell, shut it off, pop the cap, and guess at the adjustment?

 

#3 - I thought the FSM said to insulate one set of points while checking the dwell on the other.  If one set runs 4 cylinders, that won't work out so well.  How do I check & adjust the dwell on this Mallory distributor?  What am I missing here?

 

#4 - Do I set timing first, then the dwell?  What are the correct steps?

 

This one is right up Uncle Rodger or Dave's alley (two guys that seem to have forgotten more than most of us will ever know about these things)!!!

 

Thanks in advance,

 

Dan Richardson

300L Family Heirloom