78 Z ballast and condensor ????s

[widget777]

I have a stock 78 z except I have installed a Mallory #4563901 distributor. I have not started the engine yet as I am building the engine up around a new long block. What are the capacitance ratings for the condensors on the alternator and the coil? Also, the Mallory instructions require a ballast resistor in the curcuit between the ignition switch and the coil + terminal. I cannot find any reference to a ballast resistor in my manuals. Was there a ballast resisitor put in by Datsun on the 78 models? If so, where is it located?

[SteveJ]

According to the FSM, there is no ballast resistor.

Does the Mallory need to have the ballast resistor in the circuit for starting, or are you supposed to bypass the ballast resistor? The reason I ask is that all S30s with a stock ballast have two circuits coming off the ignition switch going to the ignition circuit. In start you bypass the ballast, and in run, you go through the ballast.

[zKars]

Steve is correct, 78 had no ballast and no provision to actually use it "no ballast in crank, but ballast when run" configuration, but thats ok. It just means you won't get the little boost in spark energy while starting.

First question to ask, did you get a new mallory or other type of coil? If you have the stock coil, then don't worry about the ballast resistor. Its not designed to run with one.

If you do have a new coil, and its instructions specifically call for a ballast resistor, just put the ballast resistor in series with the wire that goes to the + side of the coil.

Said another way, connect the wire that now goes to the + side if the coil to the ballast resistor (either terminal) and make a new wire that connects the other ballast resistor terminal to the + side of the coil.

[widget777]

Mallory directs user to place ballast between coil and ignition switch. I assume that it is for running and not for starting.

Did youu have any comments about the condensor questions. Perhaps there is a standard aftermarket condensor that can be applied to the coil and alternator?????

I have not checked the aftermarket coil instructions yet

Edited August 20, 2013 by widget777
correction

[SteveJ]

The condenser ratings have been posted somewhere on the board. It's not like they are critical components. Are you having noise issues on your stereo?

You should probably contact Mallory to see if you can skip the ballast resistor and run a higher resistance coil.

[TomoHawk]

The '78 has the electronic points-less ignition, and so doesn't use a ballast resistor at all. As for the condensers, I have used the usual ones you buy at the AP store, but good luck finding them, as none (in my area) carry them, or many other parts for "old cars." I was told to buy condensers via eBay (?)

[Mikes Z car]

You got me thinking TomoHawk about restoring old car capacitors by drilling out the guts (sounds drastic doesn't it?) of the old capacitor and replacing the insides with a new radial lead capacitor (connecting wires stick out of both ends of a cylinder shape) as people who restore old radios sometimes do to maintain original look. You would have to drill a small hole in the sealed off end of the metal can to get the wire on the ground end of the capacitor to feed through or possibly use an existing hole after clearing the hole of any solder if there is any. If drilling, the hole would need to be drilled on a side not normally viewable for originality appearance. That ground wire would have to be soldered to the metal can. I THINK I remember seeing a soldered point on one of those cans where the ground wire is soldered. Using the existing soldered area if there is one would make soldering a new capacitor in much easier. The can would have to be wire wheeled or otherwise made very clean for the solder to stick. I think the can is steel which I believe will solder but not as easily as copper. Not everyone would want to solder the wire though a small spade lug could be crimped on both ends I imagine with some loss of originality on the ground end. The can and the new crimped on wire could both go under the original mounting screw. The open end could be packed with (black?) silicone or anything that wouldn't melt easily. The wire coming out the open end might need insulation (what they call spaghetti insulation, looks like small heat shrink tubing) Anyone interested in writing an article on this? Maybe a new thread on this would be in order.

Edited August 21, 2013 by Mikes Z car