VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 spark control during starting?

My 29 sometimes has a hard time starting when hot, starter has to work harder to turn it when hot than it does after car has been sitting. Starter is rebuilt and valves are adjusted correctly, is this what I should expect from an 80 year old car with a 6 volt system? I wondered if the spark control was of any advantage during starting. When reading the manual it states the spark control is not needed at speeds over 22 mph, but it doesn't really specify when it is needed. I guess at the time the book was printed this may have been common knowledge. I have driven over 600 miles in the past year and never used the knob at all. My car runs and idles great and I am suprised how much power it has. When should I be using the spark advance and what benefit will it offer? Any tips on the hard starting issue?

"hard time starting" starter spinning slow? if so,

be sure battery is in good shape, all cable connects are clean and tight, and cables are correct size. when temps goes up, resistance increases.

when hot, try spinning the starter without turning on the ignition. if it's still slow that rules out timing. if it turns faster pulling the spark cable might make a difference.

Pulling out the spark knob retards the spark so you should pull it out each time that you start the car. Since the spark it retarded it makes it easier to start the car. As soon as the car starts push in the spark knob.

Also, make sure your battery is at least 600 cold cranking amps.

I think, the spark knob might be for use in case of having low quality fuel and the engine begins to "ring" during driving. With a little bit more late spark it will stop to "ring".

I hope you understand, I dont know the right term for it. We in germany say the engine rings in case of advanced spark and bad fuel. Maybe in the 1930's they had not high quality fuel everywhere and to run a car with ringing engine will follow up serious damage...

The original translated manual from GM germany says "it might be useful if you have to start the engine by handcranking"...
Maybe it is a funny note about the wellknown Ford-model T-thumb?

Stefan

After figuring out that my 32 wasnt starting because the points arm was touching the base plate, I now have a different problem. The car starts hard & it wont go past idle either. When I try to rev the engine, I get backfire from the carb & bad missing. I cant drive it. I noticed the distrib vacilates during idle too. Still spark problems? New condensor, but maybe?
Thanks
broo

In the USA we call it "Ping" instead of "Ring".

I have been very curious about the proper use of the spark control. In the owners manual it says not to use the spark control when starting the car. I have noticed that sometimes when the car is warm it does not start quite as eaisly as when it is cold. Would that be a good time to use the spark control?

Use the spark control each time you start the car.

"In the owners manual it says not to use the spark control when starting the car."

I would read this as don't advance during starting, just as JYD said. In the 28 manual, it is more explicit, retard to 0 before starting and then advance to max.

Actually, when the spark control knob is pulled out the spark is retarded. When the spark control knob is pushed all the way in the distributor is advanced. The car will start a lot easier when the spark control knob is pulled out, thus retarding the spark.

Although my car starts quite easily when cold, it is sometimes a little slow to start when the car is warm. In that situation, should one open the spark control and not use the choke? I have never use the spark control but intend to experiment with it next time I start the car.

As posted earlier this morning:

Here's a diagram that I made and posted on my site.

--Bill Barker
http://1931chevrolet.com

Great diagram Billy Boy Barker!!!!

I always start out retarded!

All the Best, Chip

Mr Junkyard Dog, why would a 29 manual state NOT to pull spark knob to retard??

I read the manual as all ways used the spark control which I have and it starts just fine. But I will recheck it again.

I have a 1929 owner's manual and it doesn't say anything about not pulling the spark knob to retard. It does say, however, "If the motor is laboring in sandy roads or on a hill, at low speed, the spark button (S) should be pulled out a slight amount to prevent an ignition or spark knock."

When the spark knob is pulled out the distributor is retarded...so when going up a hill if you pull the spark knob out to retard the spark the engine will also lose power. Also, when the spark knob is pulled out when starting, the engine turns over easier since the spark is retarded, thus the engine starts easier.

I was just reading through my green '31 owners manual and on the first page of chapter 2 it says.. quoting, "Do not retard (pull out) the "Spark" button when starting the motor. When driving, both the throttle and spark buttons should be pushed in against the instrument panel as far as they will go. This position closes the throttle and advances the spark."

Brandon

I checked Chapter II of my 1931 manual and it does say not to pull out the spark knob when starting. I rechecked my 1929 manual again and that page of Chapter II is missing. Bummer! At any rate, you don't actually have to pull the spark knob out when starting, but lots of us with early six cylinder Chevrolets discovered over the years that the with the spark knob pulled out the engine is easier to start, even when the engine is warm.

those running at the suggested 18 degrees advanced instead of the 12 described in the 31 manuals might benefit by retarding the spark during hot starting. mine indicates no apparent difference in hot starting, retarded or advanced @ 18 degrees.

with today's octane and 5 to 1 compression ratio, pinging shouldn't be a problem.