31 SA ignition timing

[Guest desoto31]

Location of timing marks on '31 6cyl? Can't seem to find on balancer or pulley, don't see a slot to flywheel.

Any help appreciated.

[Rusty_OToole]

Don't know if this applies to your cars but Chrysler flatheads from the later 30s had a unique timing system.

On the cylinder head, over #6 cylinder there is a pipe plug. By taking out this plug you can drop a screwdriver into the cylinder and feel the piston come up as you turn the engine over. When the piston is at top dead center so is #1. This is where you set the timing.

[Guest elmo39]

Rusty is right you have to remove the plug at the rear of the head , This comes fom a 1930 DeSoto 6 instuction manual .To Set Ignition Timing. The breaker points should be adjusted to 020" opening and the manual spark contol lever set in fully advanced position. the 1/8" pipe plug should be removed from the cylender head above No 6 piston and a guage rod placed through the hole and in contact with the piston head.the crankshaft should be rotated untill No6 is coming up on exhaust stroke and stopped when the piston is 035"(010" for Red Head )before top dead center. the screw which clamps the distributor timing lever to the distributor should be loosened and the distributor cap removed to see that the rotor brush is at No 1 spark plug cable terminal. the distributor clamp screw should be loosened and the distributor rotated in an anticlockwise direction, as viewed from above , untill No1 cam begins to seperate the breaker points. when doing this then distributor rotor should be pressed against the direction of rotation to be certain that all back lash is removed . the clamp screw should then be tightened and the distributor cap reistalled as well as the spark plug cables connected to the right plugs ,and thre terminals on the cap. the spark control hand lever should be checked for full advance and retard .

[Rusty_OToole]

You can use a screwdriver or make a gauge. If you make a gauge be sure you put a handle on it or make it a T bar, be sure it can't fall down inside the cylinder.

Turn the engine to TDC, mark it, and then take it out and mark .010 or .035 above the TDC mark.

When using the gauge turn the engine forward until you reach the right spot, if you go too far back off and sneak up on it again.

You want to take up all the slack in the timing gears etc in a forward direction to get an accurate setting.

[Guest desoto31]

That all makes sense and should be easy to do. Thanks to both of you for the information.

[Guest simplyconnected]

After going through all that, wouldn't it be just as easy to mark a spot (or file a groove) on the damper pulley and use a timing light, thereafter?

It sure would save a lot of time and take all the 'guess' work out.

[Rusty_OToole]

There is no guess work to it. Motorcycles were set up this way for years. It is perfectly simple and accurate.

On many cars the front pulley is buried down low and hard to get at and hard to see. The top of the head method is much easier and quicker.It is also dead accurate. Unlike vibration dampers that can slip on their hubs, or pointers that can get bent or broken over the years, or left off or replaced in the wrong spot.

You can tell the exact instant the points open in several ways. One is to use a 6 volt test light connected to the points, when the points open the light comes on, that is the instant the spark fires.

Another way is to slip a cigarette paper between the points. Slowly advance the distributor while gently pulling on the paper, when it slips free the points are just beginning to open.

Simply turn the engine to the exact spot using a simple wire gauge. Then set the points using a light or a cigarette paper.

There is a 3d method using a transistor radio. Tune the radio between stations and set it next to the engine. With the key on, turn the distributor when the points open you will hear a "pop" from the radio.

This is a very fast easy and dead accurate way to set the timing. It helps to have the spark plugs out, the engine is easier to turn. Of course you would normally take the plugs out anyway to clean or replace them at tuneup time.

[Rusty_OToole]

If you wanted to go to the trouble you could make a rod with a pipe plug thread, of just the right length. Screw it in and gently turn the engine over until it bumps against the stop and there you are.

A simple way to do this would be to get a pipe fitting that screws into the head. Set the piston to the right height by measuring. Then slide a rod down the pipe until it hits the piston, and weld or pin it in place in the pipe.

From then on you can set your timing in a jiffy.

[Guest desoto31]

I used a chain saw file with a dial indicator joined together with shrink tubing, a voltmeter to check points. Took about 10 minutes and worked perfectly.

[Guest simplyconnected]

Welded pipe fittings, rods, dial indicators, cigarette paper, wire gauge,radio interferrence, pulling plugs and cranking by hand, VOM? Seriously, that's going to beat a timing light and a dwell meter for either precision, speed, or accuracy?

I guess, to do it the old-fashioned way, these methods are acceptable, and I can think of other methods too, but I like to see what's happening. It takes less than ten seconds to clip a timing light and dwell meter on. The light will show variation (back lash and slop) in the distributor train, while the engine is running. ---just my thoughts, so don't shoot me. I use a timing light on my Harley, too. - Dave

[Guest desoto31]

Point well taken.

[Rusty_OToole]

When did timing lights come in anyway? Did they even exist in 1931?

I'm not claiming timing lights are no good. I am saying there is nothing wrong with the original method of timing 30s Chrysler products.

A good mechanic can get the timing dead accurate in a few minutes using simple hand tools. I think Mr. Desoto31 would agree.

So there are 2 of us speaking from experience.

[Guest simplyconnected]

Rusty, we don't need color or HD TV, either. Certainly they had different methods that worked great, like steam. (We still haven't unleashed the full potential of steam.) Ironworkers erected The Empire State Building in 1929. It was engineered long before then, using a sliderule.

But newer methods tell a more complete story. I'm not knocking methods from the old car days, I'm praising new methods of today. Even timing lights are nearly things of the past. Because computers do high-speed counting, there's no need to see anything.

Viewing a series of strobes from a timing light, shows much more than just a reference mark. That's the story I want to know. Dwell meters aren't absolutely necessary either, but they sure do help.

Right now, I have to get back to my blood-letting leaches and a mustard plaster. It's either a cold, or Consumption.

[Rusty_OToole]

So what are you doing looking at an old car web site?

[Guest simplyconnected]

(cough, cough) ..I dunno. I figured since I am an old car restorer, I have an old car, and I am old too, this might be a good place to spend my last cruisin' days before I go to the dream recycling plant in the sky. Who knows? Maybe we can swap a few resources along the way for the encouragement of restoring members on the other end of this here modern computer. I'm not opposed to employing modern amenities (and I suspect you aren't either), because I realize how differently my work has developed over the past 37 years at Ford Rouge. And you?