Help with Ignition Timing on Ford 392

[PosMan]

Hope somebody can give me advise on timing a Ford 392. Ford catalog suggests that the engine should be set as follows:-

Typical total mechanical advance timing at 4000 RPM 392/460/514: 30° to 32°

What does this actually mean?

Does this include the vacuum pipe been connected?

Do a set the RPM at 4000 RPM and time to 30 - 32 degrees?

Or is there a better way of doing this.

Thanks for any assistance.

[Bill D]

Remove the vacuum advance hose.

Take the engine to 4000 RPM

Adjust dizzy to show 30º to 34º deg on the pointer.

Tighten dizzy

Set idle

Reattach vacuum hose

Check idle timing. Should be 12º to 14º

[Jac Mac]

Originally Posted by Posman

Hope somebody can give me advise on timing a Ford 392. Ford catalog suggests that the engine should be set as follows:-

Typical total mechanical advance timing at 4000 RPM 392/460/514: 30° to 32°

What does this actually mean?

Does this include the vacuum pipe been connected?

Do a set the RPM at 4000 RPM and time to 30 - 32 degrees?

Or is there a better way of doing this.

Thanks for any assistance.

Exactly as it says---- Set the ignition timing to 30° / 32° BTDC at 4000RPM with the vacuum advance disconnected or plugged.

Jac Mac

[MReid]

As above, however base timing is important also. Most distributors can have the timing curve calibrated through the use of springs (determines how fast the timing comes in) and bushings (determines the total advance). Ford's recommendation is a start. The specific performance of your engine in your car may vary and you can experiment with the timing to get the best performance with no detonation. I have a Ford 392 in my Daytona Coupe. My base timing is 12 degrees and total is 34 degrees at 3000 rpm. This is the set up that gave me the best performance.

[PosMan]

Thanks for the info guy's.

What do you have the idle RPM set at for the base timing? I assume MReid you are base timing at 800rpm 12 degrees!

[MReid]

My cam is pretty aggressive and the lowest I could go is 900 rpm. Good luck PosMan!

Mark

[Jac Mac]

Posman,

The important thing is that you initally set your 'Total' timing of 32° as described at 4000RPM. Then you can adjust your idle speed, this will vary from motor to motor and is dependant on cam, carb, exhaust, compression ratio, flywheel weight etc etc. The mechanical advance curve in your distributor is controlled by the weights/springs fitted. In your case you may have a 10° advance plate fitted which would mean that your base timing should be 12° BTDC ( [10° x 2]+12° =32° ). Now dependant on the spring strength you may not be able to obtain a low enough idle speed to give a constant base timing figure to check timing with, so if you check @ 4000 RPM for 32° and then check at idle to ensure your weight mechanism is functioning correctly you will have all bases covered. You can alter the advance curve of the distributor by means of different springs to help the driveability of the car at lower RPM once you get the basics sorted.

The figures I have given above are a guess on my part-but its a pretty good guess!

Jac Mac

[PosMan]

Thanks to all for the help. All been well (weather etc) I will be looking at this Saturday.

[PosMan]

Checked the timing over the weekend, it was spot on. Hesitation seemed to be caused by accelerator pump not adjusted correctly.

Thanks for the help guys

John