I recently did a distributor rebuild on my 68 Chrysler 440 TNT. New bushings, new/used shaft and a Pertronix ignitor and Pertronix coil. Ballast resistor bypassed.
The car seemed to run "ok" but seemed to be lacking to me. It felt like there was more on the table.
The timing was set to the factory 5 deg TDC initially.
After some research I set my timing using a vacuum gauge and setting it to highest vacuum then backing it off 2 degrees.
Highest vac was 22 degrees. I set it at 20. No starter kickback
WITHOUT the advance hooked up the timing was as follows.
RPM ADVANCE
650 20
1500 28
2000 34
It seems like it stops advancing at 2000 rpm
With vacuum advance
RPM ADVANCE
650 20
1500 43
2000 50
I figure I have 14 deg mechanical advance with an additional @15 degrees vacuum.
I thought this looked good? On the test drive huge spark knock. Big spark knock as soon as you accelerate from a 15mph roll on. I kept adjusting and it settled in at 12 initial to stop the spark knock.
I am new to this distributor recurve process and have been doing more than my share of reading. Am I missing something? Am I wrong in my calculations? Do my mechanical numbers seem low?
I do have an FBO plate on the way but at this point I am a bit confused as to what setting I need. I don't believe the balancer has slipped...
I think need to remove my distributor and see what the advance plate says.
The car seemed to run "ok" but seemed to be lacking to me. It felt like there was more on the table.
The timing was set to the factory 5 deg TDC initially.
After some research I set my timing using a vacuum gauge and setting it to highest vacuum then backing it off 2 degrees.
Highest vac was 22 degrees. I set it at 20. No starter kickback
WITHOUT the advance hooked up the timing was as follows.
RPM ADVANCE
650 20
1500 28
2000 34
It seems like it stops advancing at 2000 rpm
With vacuum advance
RPM ADVANCE
650 20
1500 43
2000 50
I figure I have 14 deg mechanical advance with an additional @15 degrees vacuum.
I thought this looked good? On the test drive huge spark knock. Big spark knock as soon as you accelerate from a 15mph roll on. I kept adjusting and it settled in at 12 initial to stop the spark knock.
I am new to this distributor recurve process and have been doing more than my share of reading. Am I missing something? Am I wrong in my calculations? Do my mechanical numbers seem low?
I do have an FBO plate on the way but at this point I am a bit confused as to what setting I need. I don't believe the balancer has slipped...
I think need to remove my distributor and see what the advance plate says.