Vacuum Advance
01-15-2014, 05:07 PM
#1
Racer
Thread Starter
Vacuum Advance
I have a question on ignition vacuum advance.
Why did GM use vacuum advance versus total timing?
I just figured out my timing issues on my "64" 300 hp,
the vacuum advance can was wrong.
Thanks, John
Why did GM use vacuum advance versus total timing?
I just figured out my timing issues on my "64" 300 hp,
the vacuum advance can was wrong.
Thanks, John
01-15-2014, 05:13 PM
#2
Team Owner
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01-15-2014, 05:15 PM
#3
Team Owner
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http://www.camaros.org/pdf/timing101.pdf
01-15-2014, 05:25 PM
#4
Safety Car
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C2 of Year Finalist (appearance mods) 2019
Bottom line is at 32deg of timing you would never be able to start your car hot!! They are sometimes hard to start at 9deg (big blocks)
01-15-2014, 05:38 PM
#5
Racer
Thread Starter
Read this - it explains ignition timing and how centrifugal and vacuum advance work together to optimize driveability and performance.
http://www.camaros.org/pdf/timing101.pdf
http://www.camaros.org/pdf/timing101.pdf
The link explains how and why the vacuum advance was used.
01-15-2014, 05:44 PM
#6
Racer
Thread Starter
Putting the correct vacuum advance can really made a huge difference.
01-24-2014, 09:33 AM
#7
Instructor
Ignition timing part 2
Read this - it explains ignition timing and how centrifugal and vacuum advance work together to optimize driveability and performance.
http://www.camaros.org/pdf/timing101.pdf
http://www.camaros.org/pdf/timing101.pdf
This is a really informative article! There's a reference to Part 2; could you point me to that? I haven't been able to find it by the search function.
Many thanks,
Rob Lewis
01-24-2014, 01:34 PM
#8
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01-24-2014, 04:20 PM
#9
Burning Brakes
John,
Do a quick search for Model T ignition or How to drive a Model T Ford. That is the simplest and most graphic way to explain spark ignition.
The computerize ignition on a new C-7 works the same way. Only the computer is doing all the optimization with more inputs than the Model T driver has with his seat of the pants and tweeking with his ears.
Joe
Do a quick search for Model T ignition or How to drive a Model T Ford. That is the simplest and most graphic way to explain spark ignition.
The computerize ignition on a new C-7 works the same way. Only the computer is doing all the optimization with more inputs than the Model T driver has with his seat of the pants and tweeking with his ears.
Joe
01-24-2014, 04:57 PM
#10
Instructor
Many thanks, John. I'm afraid I'm going to have to pull the distributor (which scares the bejeezus out of me) and try the 180* turn suggested elsewhere.
Right now I've replaced the existing VAC (MS 360 12) with a B28 (this is a '65 327/365), but with the full vacuum line disconnected (15" Hg) I can't get the advance below perhaps 16+* (I've ordered a dial-back timing light to know exactly) with the VAC hard against the coil. Yes, the dwell is at 30 and idle is at 750.
So, wish me luck!
Right now I've replaced the existing VAC (MS 360 12) with a B28 (this is a '65 327/365), but with the full vacuum line disconnected (15" Hg) I can't get the advance below perhaps 16+* (I've ordered a dial-back timing light to know exactly) with the VAC hard against the coil. Yes, the dwell is at 30 and idle is at 750.
So, wish me luck!
