'57 312 Timing

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goldenberg57

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I'm currently unable to use the timing marks on my '57 312 w/ single 4 barrel w/ Fordomatic to time my engine. I've seen a number of posts on this and other communities of others having the same or similar issues with no resolution. If I adjust the timing to 6° as documented in the Ford Shop Manual the engine runs rough under a load. If I advance the timing to almost 45° the engine appears to run well and idle and under a load.

I have replaced the crankshaft damper pulley; which was off; and confirmed that it aligns with TDC (top dead center). I've also verified that the rotor does point to #1 when at TDC. And that both the intake an exhaust values are closed on #1 at TDC. So this should eliminate the pulley, timing chain and distributor alignment. I've installed a new electronic ignition, coil and replaced the plugs. I've also inspected all of the plug wires and confirmed that I have no shorting to ground. Also the vacuum appears to be good as well.

At this point I'm at a complete loss. All suggestions other than the one's above will be appreciated.

Coincidently, I have a friend that also has a '57 312 w/ single 4 barrel w/ standard transmission that has the same issue.
 

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goldenberg57 said:
I'm currently unable to use the timing marks on my '57 312 w/ single 4 barrel w/ Fordomatic to time my engine. I've seen a number of posts on this and other communities of others having the same or similar issues with no resolution. If I adjust the timing to 6° as documented in the Ford Shop Manual the engine runs rough under a load. If I advance the timing to almost 45° the engine appears to run well and idle and under a load.

I have replaced the crankshaft damper pulley; which was off; and confirmed that it aligns with TDC (top dead center). I've also verified that the rotor does point to #1 when at TDC. And that both the intake an exhaust values are closed on #1 at TDC. So this should eliminate the pulley, timing chain and distributor alignment. I've installed a new electronic ignition, coil and replaced the plugs. I've also inspected all of the plug wires and confirmed that I have no shorting to ground. Also the vacuum appears to be good as well.

At this point I'm at a complete loss. All suggestions other than the one's above will be appreciated.

Coincidently, I have a friend that also has a '57 312 w/ single 4 barrel w/ standard transmission that has the same issue.
Click to expand...
Have you checked the vacuum advance on your distributor and is it connected to the correct vacuum port on the carburetor?
 
This may sound silly but are you confident in your timing light? Also, some timing lights have dwell adjustment knobs and if that's not zeroed out, you'll get false readings.

All that said, I'd tend to trust my ear and adjust timing to where the car runs best. But that doesn't solve the mystery...
 
what type electronic ignition? a pertonix type or a complete distributor? if you are using the original distributor, the vacuum advance plate could be worn enough to change the gap of the points or the pickup coil of the pertronix. Unhook the vacuum line, plug it. then have the distributor hold-down clamp loosened enough to be able to adjust the timing with the engine running. as you increase RPM, turn the distributor a small amount each way until the engine runs best. you will have to play with the setting to get it best you can.
 
Jack-in-sac makes a good point. You can connect vacuum advance to ported vacuum on the car or to manifold vacuum. I'm running my '64 390 vacuum advance on manifold now and finding the car has better throttle response.

But, when I switch between manifold and ported vacuum, I have to adjust the idle screw, but not the initial timing.
 
64ZCODE said:
This may sound silly but are you confident in your timing light? Also, some timing lights have dwell adjustment knobs and if that's not zeroed out, you'll get false readings.

All that said, I'd tend to trust my ear and adjust timing to where the car runs best. But that doesn't solve the mystery...
Click to expand...
 
henro said:
what type electronic ignition? a pertonix type or a complete distributor? if you are using the original distributor, the vacuum advance plate could be worn enough to change the gap of the points or the pickup coil of the pertronix. Unhook the vacuum line, plug it. then have the distributor hold-down clamp loosened enough to be able to adjust the timing with the engine running. as you increase RPM, turn the distributor a small amount each way until the engine runs best. you will have to play with the setting to get it best you can.
Click to expand...
Protonix Ignitor II was just installed and gaped with tool provided. Thanks for the adjustment suggestions as well.
 
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