VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 Timing 1950 216 / 235

The eratic miss I had seems to have been due to timing / carb adjustment - mainly the timing.

To time the engine, the manual says to rotate the distributor until the ball lines up with the pointer. OK. On the distributor side of the flywheel housing is an opening with a pointer-needle. The flywheel has a number of features that I see when trying to do the timing. First there is a circle. Toward a more retarded spark, there is what looks like half a sphere carved or cast into the flywheel surface. Toward an even more retarded spark there is a feature that looks like an empty bolt hole - a threaded hole.

I believe the middle feature, the 'half sphere', is the ball to which the manual refers that is supposed to line up with the pointer-needle at regular idle with the choke all the way in. Is this correct?

I have no idea what 400 rpms is supposed to be except that it just sounds like a good idle. How do you measure that?

Man, my gas mileage is in the dumper. Maybe I have some brakes draggin' or something.

Thanks,

Lee Prairie

Stop the flywheel so you can see the steel ball through the window. Do the best you can to clean the area around the ball with solvent or anything you have. Wipe the area clean and dry. Use a small paint brush to paint the area around the ball with white paint.

When timing the engine reduce the engine RPM to as low as it will run smoothly. Move the distributor to place the ball in the center of the hole and aline with the pointer.

Ray, the manual indicates to run the engine at 'idle speed' to set the timing. In one place, idle speed is 450 - 500 rpms; in another, it is 400 rpms. With the valve cover off, one can actually count the number of revolutions by counting the number of times a valve is depressed (put your finger on the rocker and measure the time needed to count 10 depressings five times (50 depressings) using the stop clock in your cell phone).

It seems to me that your method (timing the slowest possible idle) will have all other running conditions with an advanced spark from the vacuum advance. Is this what you intend? Am I correct about that? After you time it your way, do you then set the idle speed adjustment to make a 400-500 rpm idle (without re-timing)?

Lee

The idea is to insure the vacuum advance is NOT activated. To do this reduce the RPM or disconnect the vacuum advance vacuum line. It is easier just to reduce the idle. When timed, return the idle RPM to specks and adjust the air adjust on the carburetor.

(Keep in mind this is not a discourse on a tune-up, but how to set the basic timing).

Lee you are worrying too much. The round ball sunk into the flywheel IS THE TIMING MARK, not necessarily TDC, When the engine is running at a slow idle ( don't worry about how many rpms that is exactly) use the ball in the window ..... when your timing light shows the ball under the pointer then that is where you want the distributor set to fire # 1 cylinder according to the factory reccomendation, tighten the distributor down with the octane indicator on Zero, of course that is made with an engine that has the correct point gap set in the distributor. If you want to "Tweek" the timing use the needle on the octane indicator (base of the vacuum advance) as a reference of where you started.
I never have needed to disconnect the vacuum advance vacuum line, the idle circuit in the carb takes care of the vacuum advance at an idle, at least that and the placement of the Timing mark ball, I think!....but if you do disconnect the line, be sure to plug the vacuum port on the base of the carb.

Now if you want to work on the gas milage, maybe you have a low speed rear end, that can be changed. also check out the air cleaner for a dirty element. Also be sure the heat riser is worhing. Do you have an oil bath air cleaner? Next is a fine tuning of the carb. Jetting etc. and float and needle valve work. If you have a Carter W1 I can't help you, but there are many guys around here that can. Good luck!

And to further confuse things that will be only the base timing for 80 octane gas. That was the octane of regular in 1950. The timing can then be adjusted (advanced) another 8 degrees for todays higher octane gas. Read the octane selector part of the shop manual or owners manual. The more it is advanced the the more power the engine will produce and the fuel milage will also increase.
With the heavy non-aerodynamic truck with the low gearing you will be lucky to get much more the 13 or 14 MPG on the highway.

it's easy to remember, advancing the timing speeds up the idle, retarding slows the idle

Actually, it's no biggie on the timing. Set the idle speed where you want it (by ear if you have to), and with the vacuum advance disconnected and plugged (only if needed) using a timing light that is connected to the number one spark plug, line up the steel ball on the flywheel with the pointer. Tighten up the distributor and you are all set. If you want the timing advanced more for today's fuel, then adjust the octane selector accordingly. After the adjustment, if the idle speed is too high then set it down to where you would like to have it..again, by ear if necessary. As Chev Nut says, the shop manual describes how to do it.

Thanks to everyone for comments.

Ray, I agree that your method makes sure the vacuum advance is not activated while you're timing the engine. But everything above that slowest possible idle will have vacuum advance activated (which was my point).

I like to use the 10% ethanol which usually has an octane rating of about 87 - 89 (rarely 90). The ethanol will dissolve water moisture that condenses in the tank and help sweep it through the 'system'. The energy content of ethanol is lower than straight gasoline (so mileage is lower and even more so for the E85 blend). I'll use the octane setting at the vacuum advance to tweak that.

Also, I felt that the truck had less 'power' for accelerating with the timing I set for the engine (ball aligned with needle at about 400 rpm, carb set with idle mix 2 turns out from all-the-way-in.

I still get a better sounding 'idle' (but faster idle) with the choke out a little.

I re-torqued the head bolts yesterday so I had the rockers off. Some of them have wear depressions deep enough to catch one's finger nail on. So, there's more tappet clatter than I like. The 3 piece rocker arm assembly is annoying to handle. But one can handle it better by putting at least the middle most bolt in each 'half' of the assembly while it is off to hold it together - this also helps re-installing it.

Lee Prairie