James_Douglas Posted March 28, 2013 Report Share Posted March 28, 2013 Hi all,I am talking with Mallory Ignition. They still have the prints for the old Dual Point adjustable mechanical advance, with adjustable vacuum advance, distributors.Although Auto-Lite made a dozen different distributors for the flathead six's, which many use different rotors, caps, and vacuum cans, they are all basically the same if you set the advance curves to your cam and carburation.I am thinking of getting two of these made up for my cars. Hotter spark, ability to set the advance to the new fuels, and be able to stock one set of spares for both cars.The only thing is that they are going to be expansive. In the $500 range. I did ask for the quote to include the housing with the tach drive. I have some folks in Sonoma, CA that makes some special little tachs that will work with the tach drive that look good on the steering column on the car.If anyone else is interested let me know. If more folks are interested I may be able to get the price down.Best, James 1 Quote Link to comment Share on other sites More sharing options...
Mark D Posted March 28, 2013 Report Share Posted March 28, 2013 Wow - saw a couple of these on ebay a few months ago.. looks like I should've grabbed them at $40 each. Like to hear how this goes for you. Quote Link to comment Share on other sites More sharing options...
greg g Posted March 28, 2013 Report Share Posted March 28, 2013 (edited) Can some one please explain to me why, in a basically stock or even slightly modified, low compression engine, a hotter, longer, brighter, bigger spark is needed? A given air fuel mixture will ignite and burn as hot and as long, and its flame front will spread the same, no matter what ignites it. The critical factor is when the spark is delivered, if it does its job of lighting off the mix, anything else is pretty much wasted electricity. Now on higher compression, higher revving, or engines with forced induction, I can see where bigger brighter hotter longer might make some difference, but we are talking pretty basic Briggs and Stratton tech here with stock stuff. Edited March 28, 2013 by greg g 1 Quote Link to comment Share on other sites More sharing options...
Daliant. Posted March 28, 2013 Report Share Posted March 28, 2013 You'd be better off with electronic ignition over the dual point setup, if you have 12v. A hotter spark will light off a engine quicker on cold damp mornings so if anything it'll save some wear and tear on the starter. As for making more horsepower I doubt there would be much improvement on the top end unless the spark advance was tailored to that particular engine, Idle quality will probably improve though. Quote Link to comment Share on other sites More sharing options...
James_Douglas Posted March 28, 2013 Author Report Share Posted March 28, 2013 My flathead sixes are all running around 8.25 to 1. When MOPAR raised the compression over 7.5 to 1 around 1955 they went to 12 volts for a reason. They needed more coil secondary voltage. I ran an old dual point that one of the other car guys I know loaned me while my dizzy was out waiting on a rebuilt vacuum can some time ago. I did not change a thing on the car and it started and ran better than my NOS Auto-lite dizzy that had been set up on a Sun Distributor machine. Both dizzy had very close advance curves. The only real difference was the dual point allowing more coil saturation. I also just want all my dizzy's to be the same so I can stock one set of spares. I also like having a tach and the tach drive housing on the Mallory will allow that. Also, from a money point to build a as new Auto-lite Distributor I figure based on ebay sales: Core unit $40 NOS breaker plate loaded with new wires and condenser and points $50 If shaft is not perfect then lathe down $50 Or NOS one at $100 New bushings and shop time to line hone $75 (reaming does not do it as shaft has to be near perfect for dwell not to float) New cap and rotor $30 Rebuilt vacuum chamber $75 Sub-Total of around $300. Plus, I still have to put it all together. For an extra $200, I get tach drive, better spark and someone else does the work. James Quote Link to comment Share on other sites More sharing options...
greg g Posted March 28, 2013 Report Share Posted March 28, 2013 James, I wasn't trying to criticize your choice, just inquiring of why it would be necessary assuming everything else is stock. Quote Link to comment Share on other sites More sharing options...
James_Douglas Posted March 29, 2013 Author Report Share Posted March 29, 2013 James, I wasn't trying to criticize your choice, just inquiring of why it would be necessary assuming everything else is stock. Greg, Everything you said was correct. It all come down to the specific situation. One thing is when rebuilding something to as new condition, you can in fact spend almost as much as new replacement---if one can be found. Best, James Quote Link to comment Share on other sites More sharing options...
1941Rick Posted March 29, 2013 Report Share Posted March 29, 2013 Save your money and convert to electronic......converting to a slant six system is easy and cheap.....and so much more dependable.... Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 29, 2013 Report Share Posted March 29, 2013 You'd be better off with electronic ignition over the dual point setup, if you have 12v. I know we have been down this road many times. But once again my reasons for running dual points are as follows. Greater coil saturation time and repair parts availability. Also if one set of contact points fail I can disable that set in short order and continue on down the road using the other set. With an electronic replacement is the coil saturation time (dwell angle) increased? Are replacment parts available in short order? If it fails on the road what can you do to get going again? Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted March 29, 2013 Report Share Posted March 29, 2013 I bought a new Mallory "Double Life" distributor for my 1951 plymouth in 1970. Cost close to $100.00. It's still working fine in the car today! I also have one in mt 48T&C eight cylinder. It works great too. Bob Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 29, 2013 Report Share Posted March 29, 2013 I bought a new Mallory "Double Life" distributor for my 1951 plymouth in 1970. Cost close to $100.00. It's still working fine in the car today! I also have one in mt 48T&C eight cylinder. It works great too. Bob 3 lobe cam? Does it spin at twice the speed of a normal distributor? Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted March 29, 2013 Report Share Posted March 29, 2013 (edited) The "Double Life" distributor cam spins at normal 1/2 crankshft speed. Each set of points fires it's own set of cylinders- One condensor and one coil. The points will not bounce at high RPM and supposedly they last twice as long too because of the 3 lobe - they open and close half as often as a six lobe cam. The lobes are smoother too and prevent wear and point bounce.I should still have the original paper work on it. I will see if I have it and post it. Point gap is .020" Best picture I could find. Edited March 30, 2013 by Dodgeb4ya Quote Link to comment Share on other sites More sharing options...
Don Coatney Posted March 29, 2013 Report Share Posted March 29, 2013 Interesting concept. With a three lobe cam is the dwell angle increased? Quote Link to comment Share on other sites More sharing options...
TodFitch Posted March 29, 2013 Report Share Posted March 29, 2013 Interesting concept. With a three lobe cam is the dwell angle increased? Looking at those photos, I think the two sets of points are wired in series so if either opens you get a spark. The dwell might be increased but I think the main advantage would be that the point gap can be larger which should decrease arcing and the arcing wear is divided between the two sets of points. Quote Link to comment Share on other sites More sharing options...
wayfarer Posted March 29, 2013 Report Share Posted March 29, 2013 With an electronic replacement is the coil saturation time (dwell angle) increased? Are replacment parts available in short order? If it fails on the road what can you do to get going again? There are multiple reasons that MotherMopar went to Electronic in 1970 and overall better engine performance was one of them. With the Mopar electronic system parts certainly are available everywhere, and at low cost. The ballast resistor sells for about $2 so carrying a spare is a non-issue, and the ecu rarely fails but, again, spares can be tossed in the glove box. The single biggest and most common runability issue with the Mopar electronic system is loss of proper ground to the ecu which is an easy fix during the initial install. 1 Quote Link to comment Share on other sites More sharing options...
James_Douglas Posted March 29, 2013 Author Report Share Posted March 29, 2013 If I was going to switch to 12 volt, I would consider electronic. However, all my 6 volt cars work very well on 6 volts and so I have no other reason to swap them over. I am going to follow up with Mallory and ask about that double life unit. What is the model number of that unit? Best, James Quote Link to comment Share on other sites More sharing options...
greg g Posted March 30, 2013 Report Share Posted March 30, 2013 My old Mazda rotary engine had a dist with two sets of points but it had 2 spark plugs per rotor chamber. A leading plug and a trailing plug. Don;t know what the deal was but the leading plug points always burnt or wore out way before the trailing ones. The deal was to buy one set on new points, move the trailing set to the lead plugs, and the new set to the trailing set. Strange but effective. Quote Link to comment Share on other sites More sharing options...
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