Chrysler Rotor buttons? Or change to elec ign?

[snwwlkr]

I've got 3 Chrysler motors, only one presently running but all are good potential runners sitting in the line up waiting their turn, each needing various this and that. They are 70, 75 and 85hp 3cyl. and 2 of those have points type distributors, both of those distributors have busted rotor buttons. Anyone know of a cheap source for rotor buttons? I searched ebay, googled, checked the online parts places I know of including iboats and searched this great forum. Conclusion, its not looking good. Its not looking like these are available anymore. Also called Franz but he wasn't answering........ Now wondering if I do find them that they may be $$$.....Or???? Should I use that money instead to invest in upgrading (if you want to call it that, I dont know, thats why I'm asking) to electronic ignition (breakerless)? And if I do upgrade to breakerless is there a particular model that is the most reliable...?

I'm going out this morning to begin my breakerless education, haven't messed with them much yet. Busted my last brittle old rotor button yesterday so going to pull the one breakerless distributor off of that motor and put it on my one present running motor to see if she'll work...

 

[ben jones]

Re: Chrysler Rotor buttons? Or change to elec ign?

I have an electronic ignition on my 75 hp it has a cd box and a signal wire going to the distrubutor to tell it when to fire, If you get the correct box to go with the electronic dist. it should work fine. I will warn you the boxes are an "iffy" part . they do go bad. There may be another way to do it but this is what I know because its what is on mine. Mine also has gapless plugs and a single coil with internal resistor.

 

[snwwlkr]

Re: Chrysler Rotor buttons? Or change to elec ign?

Mine are all three type IV magnapower, cdi unit, single coil. The point distributors all are one wire (not counting ground) with a black/white from the cdi unit. The breakerless I have (mallory written on dist cap) has two post for two wires on the distributor, a blk/wht from the cdi and a blu from the terminal strip block. Reading mySeloc book I didnt see a one wire breakerless type distributor that only uses one wire for these motors..???

 

[Frank Acampora]

Re: Chrysler Rotor buttons? Or change to elec ign?

It doesn't matter if you have Motorola electronic or not -- with the distributor you still need the center button.

The points distributor can easily be converted to electronic--electric eye. All you need to do is drill another hole in the side for the second terminal and change out the shaft/rotor for a shaft/shutter. Everything else bolts into existing holes.

In operation, the blue wire powers the electric eye. The shutter alternately opens and blocks the light beam. When the light beam is either opened or blocked--I forget which now-- A signal or absence of one through the white and black striped wire causes a gate transistor to open and dump the capacitors into the coil. Because they dump and empty so quickly, magnetic field in the coil rises and collpses quickly too, and a sharp high voltage pulse is sent through the distributor to the correct plug.

The center button is nothing but a graphite motor "brush." So, all you need to do is find a correctly sized set of cylindrical brushes (from a drill, screwdriver etc.) and you have two center electrodes. All you need to do is remember to re-use the existing spring, or if the brush is shorter than the existing center button, use a different spring. In a pinch, even a square or rectangular one will do. After all, the rotor is only spinning on the tip with light pressure--only enough to ensure electrical contact.

The engines themselves CAN be converted to Prestolite distributorless electronic but is is not just a bolt-on. You need to do some modifications. There was a recent post on this by Tater76. Do a search for it.

 

[snwwlkr]

Re: Chrysler Rotor buttons? Or change to elec ign?

SUCCESS!!! Swapped in my breakerless distributor and she fired right up....that is, after performing the static timing adjustment.. Took all of 45 minutes max.. After examining the distributor caps they looked exactly the same and even the same part#. I decided since I knew the one I had been using worked, I would stick with it, one less variable.

Still would like opinions of reliability of points vs breakerless etc...

 

[Frank Acampora]

Re: Chrysler Rotor buttons? Or change to elec ign?

Electronic distributor is way more reliable. No points to clean or set. No points to wander or float at high RPM. All in all, just generally better.

Yes, Caps are the same.

The only negative to the electric eye is that if one goes bad, there is no way to test it. the only thing you can do is swap in a known good one. If taht works, then the original one is bad. It is a little aggravating.

Just be certain that after swapping distributors the drive belt is not too tight. A tight drive belt will hinder distributor movement and cause (believe it or not) SHIFTING problems. Too loose and timing will wander a bit.

Correct tightness is set by having an .010 steel feeler gauge, when pointed like a finger in the center of the belt, depress the belt about 1/8 to 3/16 inch before it (the gauge) bends.