I can't find any timing marks on my 1932 PA for a "modern" timing light. Is it possible that this motor did not come with timing marks? I've found references to setting the timing by using a guage (basically a dial indicator) against the top of piston #4 and setting the points to open 0.046" before the top of piston travel. Is this the best/only way to set the timing on this motor?
I'm asking these questions because my recently acquired Plymouth came with the vacuum advance nonfunctional and disabled (!) Surprisingly it runs reasonably well in this state, but seems "weak" under load and gets very poor gas mileage. SO: I'd like to take the distributor apart and remedy that problem, but not until I know how best to set the timing.
...Thanks in advance :)
Not sure on the old four cylinders, but the 1933 six has a small cover plate on the flywheel housing (drive side near the starter motor) that you open to expose a pointer. There are timing marks on the flywheel that you line things up with. Maybe the four is the same. I'll have to check on Bob's PA one of these days.
I have used a modern timing light to adjust the timing but usually I just static time it using the beeper continuity setting on my volt-ohm meter. I used the variable advance timing light when I first got things together to verify that the distributor advance was working properly.
If you want to use a 12v negative ground timing light on your 6v positive ground car, simply hook the power leads on the timing light to a 12v battery and the trigger cable to the #1 plug wire.
From out of the 1932 manual:
"To set ignition timing; The breaker points must be adjusted to .020" opening. The ignition is set by first removing the inspection cover located on the left side of flywheel housing directly below the starter. The crankshaft should then be rotated, by means of the hand crank, until No.1 piston is coming up on compression stroke and stopped when the line on the flywheel, marked "DC", coincides with the ignition mark on the timing incicator plate, marked "IGN 10 deg. The screw which clamps the distributor timing lever to the distributor should next be loosened and the distributor body rotated in an anti-clockwise direction, as viewed from above, until No. 1 cam begins to separate the breaker points. While doing this the distributor rotor should be pressed against the direction of rotation to be certain that all backlash is removed. The clamp screw should then be tightened and the distributor cap re-installed".
Interesting :)? Well, I've taken a hard look at the flywheel housing and there is no inspection plate anywhere near the starter.? That seems to agree with the info at http://www.carnut.com/specs/gen/ply30.html which shows That the 1932 PB timing is at "IGN10" as you describe, but the 1931 PA is at 0.046".? SO: I'll be checking soon to see if I can get that (rusty) little plug over #4 to come out so that I can set the timing with a rod on top of the piston and my dial indicator.
FYI: The factory considered the PA a 1932 (and that's how it is registered) but all the references call it out as a 1931 (which is when it was produced).? I think I'll start referring to it as a 1931 myself to avoid confusion with the 1932 PB.
Bryan, Another way of setting the timing is to use a vacuum gauge attached to the intake manifold [windshield wiper port is good]. Be certain that you have the points set dead on; loosen the distributor; at normal engine idle, turn the distributor until you get a maximim vacuum reading; back off the distributor to loose 1 inch of vacuum and tighten down the distributor. That's all there is to it but I have to tell you that some may disagree with this procedure but that is how I do it on all my motors and it works very well for me.
32cabrio: Thanks!? I read up on using vacuum to set timing and decided to give that a try.? This is particularly relevant since I'm running the spark plugs at a larger gap (currently 0.035", may try 0.040"), which is supposed to work best with the timing advanced a bit more.? So I used the vacuum gauge to set the timing and took it for a spin with particular attention to any pinging.? No pinging was observed and the engine now runs with substantially more power and smoothness under load? ;D
I also adjusted the idle circuit.? The Vacuum readings look generally quite good -- a few minor issues observed that may eventually need attention.
Thanks to everyone for the advice -- the car is really running great right now!!
Bryan, Thanks for reporting on your results. Too few requesters do that. One cautiion: unless you're running a "HOt" coil or an electronic ignition, I wouldn't go too far out on the plug gap. Each time that is done, something else has to change to compensate and I'm not sure you're gaining anything. A wider gap requires the coil to 'work harder" and could shorten it's life un-necessarily. If you have the original type ignition system, I would start with the original specs. and go from there.