VCCA Home Forums TECHNICAL - 1945 AND NEWER 1949-1954 timing adjustment

I have a 53 bel-air, and I am tyring to adjust the timing. The manuals don't talk a lot about adjusting timing. Mine is currently set just to the right of a small ball on the flywheel. Which indicates very advance if any at all. Also to set the timing do you have to remove the vacum line to the vacum advance before adjustment. What should the timing be set at?

The correct procedure is to remove and plug the line and set the pointer on the ball. If you understand the procedure you can leave it connected. Just observe the distributor and insure it does not move during the procedure.

The vacum pickup point on earlier chevs is located above the throttle plate so at idle there is no vacumn present and therefore unnecessary to disconnect the line to the vacumn advance when setting timing. The manual for 49/54 does not mention disconnecting the line at all.

I don't have any engine older that a 1953 with vacuum advance, and the vacuum advance is hooked to the bottom of the throttle body. I have never disconnected the vaccum advance since I checked it out once while it was idleing, I disconnected the vacuum advance and the distributor didn't move, the engine just sputtered a bit. You also need to check the vacuum advance by reving the engine up and downand watching to see if the vacuum advance moves the distributor. I also check the vacuum advance with a Mini-Vac to see if it works, or will hold a vacuum. I set the timing with a timing light on zero advance and it runs fine, with the light hitting the ball in the center of the window. You also need to be sure the points are set with the right gap (dwell).

Ok, so the vacuum advance doesn't have to be disconnected to adjust the timing. My vacuum advance works when I rev the motor up above idle. Currently the timing is maybe 2 degrees advanced.

Now, I also have a 31 Roadster and Bill Barker's site has different settings for timing and plug gap. For the 53 I read somewhere but can't locate it that the timing should be set at 8 degrees advanced. I also read that it should be set so that there is a little ping when the engine is working hard (such as going up a steep hill). Does anyone have any information on modified timing and plug gap for the 53? The reason for the modification is the improvement in gasoline.

The correct initial timing would be to set the octane selector dial on "0" and have the ball in the flywheel line up with the pointer. The timing then would be set for the octane of regular grade fuel in 1953 (about 80 octane). To fine tune the timing you can then move the octane selector towards the advance. Years ago it would have been until the engine gives a slight ping under full throttle at low speed. With todays higher octane gas (yes, 87 octane is higher than preimum in 1953) it may require too much advance to get the engine to ping. On mine I advance as far as possible (using the octane selector because then you can always find your way back without the timing light)....if you go for to much advance the engine will turn over hard or kick-back on starting or if a stick will surge at medium speeds, worse when backing off on the gas.
Your Canadian 1953 235 will have the US Power Glide engine for a stick or P.G> it has a 7.5 to 1 compression ratio. While higher compression than any 216 it would still be considered a fairly low comprssion by todays standards.
Just play with it til you find the "sweet spot".

For the new 1953 I had I would set the timing so it would ping like heck with regular and then run premium (ethyl).




























with more advance with in reason the engine will develope more power and produce better gas mileage.

Remember what I said? "I don't have a engine with vacuum advance older than a 1953." I really don't like to hear the engine ping. I won't say either way about a 1931 engine......I generally try to follow instructions as written in an official Chevrolet Shop Manual for each specific car. I suggest everyone that does own a vintage Chevrolet have a shop or repair manual, even if you don't do most of the repairs yourself, it don't hurt to know how that they are put together, and come apart.

I have a repair manual for the 53 and I think I am on the right track. I will be adjusting the timing to take into account the higher quality gas without going too extreme. The current setting has the engine running a little rich and by advancing the timing a little it should help it run a little leaner. Thanks for the input.

Well I don't know about timing having much effect on how rich an engine runs. I always mske any changes to the fuel-air mixture with carburation.

The carburetor and air flow determines as how lean or rich the mixture is.
But you can advance the timing farther with a rich mixture because the rich mixture burns slower. If the mixture is too lean it can cause excessive pinging.

Well my plugs are black which I was told indicates a rich mixture. The carburetor is stock with the exception of the idle jet there isn't much adjustment that I can make there. The choke works properly. I was told by advancing the timing it would burn the fuel more efficiently and therefore leave fewer residues effectively making it appear to be a leaner mixture.

If your carb is stock (Rochester) there are several things that you can do to make it run with the correct air-fuel mixture, change the float level, Be sure the float needle and seat valve is holding, make sure the air cleaner is open and free flowing, change the main jet, make sure everything is clean and the choke is working up to par.