VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1937-1945 Engine timing on '37

I noticed on one of the recent posts that Chevgene provided a proceedure for setting the timing on a '40. This proceedure was to set the timing so the pointer lines up with the ball on the flywheel and then advance the timing 4 marks on the octane selector. Would the same recommendation apply for the '37?

You can go up to 8 Deg extra advance on 1933 and up engines. The base timing was for the low octane fuel at the time the car was made. Read either the shop manual or owners manual about use of the octane selector. The octane selector allowed the owner to adjust the timing to the grade of gas being used with out the use of a timing light.
I would say that the octane selector is the most misunder stood feature on the Chevrolet engine.
If you doo advance the timing too far you will know it. The starter will have trouble turning the engine over when hot.

If set too far in advance the engine can recoil back and in some cases break the Bendix. If you hit the starter and it fights back, it is advanced too far. Retard until it turns easily and starts immediately.

Since this topic is discussing engine timing on a 1937, I have one that is somewhat related. I wasn't paying close attention when my engine was removed (by several club members) and didn't mark the flywheel when it was taken off. It's time to replace it andI'm not sure how to correctly position it. The manual states that "the four nuts, in addition to holding the flywheel in place, also acts as dowel pins to locate the flywheel"---exactly what does that mean? The manual goes on to say "Another dowel pin, pressed into the flange of the crankshaft serves to properly locate the flywheel in its correct position before the bols are assembled in place." I cannot find a dowel pin on the crankshaft.

Any ideas??

Thrasher

If my memory is correct I believe the flywheel mounting holes are not symmetrical and the flywheel can only be mounted in one position on the crankshaft.

Is there a dowl pin hole on the crankshaft flange. It will be much smaller than the four bolt holes. The dowl may have been removed. Should also be a small matching hole in the flywheel.

That is a good possiblity--I will have a better idea next week when I take the motor off the engine stand and start the reassembly process. Thanks for helping!

Thrasher

Hello Gene,

There is a fifth hole on the flywheel and for the life of me, I can't find anything on the crankshaft to align it with. My wife likes to constantly remind me, "You're no mechanic." I'm sure it will all come together when I start putting parts back together.

Thrasher

Bingo!!!

I have been haunted by a mystery for many years about my 1948 Chevy 216 engine (I am using it as a driver for my 38 Chevy while I am rebuilding my 1938 Chevy original engine). After rebuilding the 1948 engine it ran perfectly. But the next summer I was on a trip from Boston to Dayton Ohio when the cam shaft gear (nylon) lost all its teeth on I80. I had to tow her home. When I asked the machine shop to press on the new Nylon gear they dropped my cam shaft and bent it. They were honest enough to let me know and said they would try to straighten it. I was never sure if they did, but they said it was straight when they returned it to me with the new gear (today, I would never let anyone do anything on the car I could do myself).

I began to experience a failure to start the engine when it got hot. It would always start perfectly when cold. Sometimes when hot, I would get "lucky" and it would go around very reluctantly and hesitate and just start by the hair on its chinny chin chin, but oviously it was not happy and neither was I. Most other times I jsut plain had to wait til it completely cooled off to "dead cold" condition.

I began to think about what it could be and finally drew up a small list of possibilities that inlcluded:
1. A touchy starter that was totally unrelated to a "snow bird" and would just plain quit when the temperature got too hot. [???]
2. The cam had residual stress in it from the bend and straightening operations that was activated by temperature causing the cam to offer enough resistance to turning when hot that it would overwhelm the starter.

After this short list I was puzzled and was left scratching my head... until I read Gene's post..."If you doo advance the timing too far you will know it. The starter will have trouble turning the engine over when hot."...bingo is this it?

Please let me know more about this as I never suspected the timing being too far advanced. As far as I know the engine never complained (to me) about the timing I offered it for a setting. Sometimes the nylon pad on the points that makes contact with the 6 sided cam on the distributor shaft would wear I just would have to reset the points to proper gap.

Thanks for info that could solve a mystery that has been in my worst dreams for years. Would there be any other signs that the timing is too far advanced?

Mike

Joe,
I looked at the new 1937-1939 crankshaft I have. The stud is quite large and mid-way between two of the bolt holes. If you lay the crankshaft so the stud is is to the top the key way for the balancer (up front) is on the bottom.