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Joined: Jun 2015
Posts: 269
Backyard Mechanic
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OP
Backyard Mechanic
Joined: Jun 2015
Posts: 269 |
I have never used the timing advance on my 31, how do you all use it if at all. Is it beneficial at higher speeds or other times. I'm sure it is there for a reason.
31 Chevy Roadster
64 Corvette
76 Corvette
77 Grand Prix
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ChatMaster - 7,000
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ChatMaster - 7,000
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If you are referring to the "spark" control on the dash it is basically used when starting. Pulling the knob out retards the timing . I use mine on the 32 all the time when starting.
Steve D
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Joined: Jun 2015
Posts: 269
Backyard Mechanic
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OP
Backyard Mechanic
Joined: Jun 2015
Posts: 269 |
Yes that is it, I will try using it the next time I start the car. I have been starting it with some instructions I saw in one of the manuals that suggest throttle out 1/4 inch and full choke. Thank you.
31 Chevy Roadster
64 Corvette
76 Corvette
77 Grand Prix
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Joined: Nov 2001
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Tech Advisor ChatMaster - 25,000
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Tech Advisor ChatMaster - 25,000
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The Mangy Old Mutt
"If It's Not Junk.....It's Not Treasure!"
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Joined: Nov 2002
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ChatMaster - 7,000
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ChatMaster - 7,000
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Many if not most on this site with 31-32's have the timing set at 18 deg advanced and the plugs gapped at .040 rather than the printed factory specs of .012 and .024, This is mainly due to the newer and higher octane fuel today rather than what was available when the cars were new.
Steve D
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Joined: Jun 2018
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Grease Monkey
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Grease Monkey
Joined: Jun 2018
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Do those specs benefit the 1929 as well or stick with factory?
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Joined: Nov 2001
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Tech Advisor ChatMaster - 25,000
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Tech Advisor ChatMaster - 25,000
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The Mangy Old Mutt
"If It's Not Junk.....It's Not Treasure!"
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Joined: Jul 2017
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Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Jul 2017
Posts: 197 |
Just today I went with the conventional wisdom about the 18º advance......THAT perked up the ol' girl.......  You WILL need to use the spark control button for starting. This link made the procedure crystal clear as I couldn't tell exactly what I was seeing on the flywheel. https://1931chevrolet.com/specs7c.htm
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Joined: Feb 2014
Posts: 35
Shade Tree Mechanic
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Shade Tree Mechanic
Joined: Feb 2014
Posts: 35 |
And just to add, one of the things I read was to use the retard on a hill if you start to get pinging with a bad batch of gas!
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Joined: Jun 2015
Posts: 269
Backyard Mechanic
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OP
Backyard Mechanic
Joined: Jun 2015
Posts: 269 |
The retard does help starting, it doesn't seem to need to crank as long and I can push in the choke much sooner. I have started the car a half dozen times since my first post and the difference is noticeable.
31 Chevy Roadster
64 Corvette
76 Corvette
77 Grand Prix
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ChatMaster - 3,000
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ChatMaster - 3,000
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The idea behind retarding the spark for cranking is to make sure the spark happens when the piston is close to or at TDC so the explosion in the cylinder does not fight the rising of the piston and go against the rotation of the crank.
After the engine is running a few moments, you advance the spark (push in the knob) and the spark now happens while the piston is still compressing the fuel/air mixture. Since the engine is running faster than when starting, the timing of the explosion is such that by the time the 'fire' enters the combustion chamber, the piston is at the top of its travel in the cylinder and is ready to really use all the power the fireball is generating.
Cheers, Dean
Dean 'Rustoholic' Meltz old and ugly is beautiful!
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