- Oct 21, 2006
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This is from Ford Racing's web site.
Engine Installation and Tuning Tips.
Typical total mechanical advanced timing at 4000rpms for Ford Racing Performance
Parts crate engines: 5.0L : 36 to 38 degrees
My timing is at 15 degrees advanced at idle with timing the spout disconnected.
I tried to check it to see if it was at 36 to 38 degrees at 4000 rpms and it still read 15 degrees. Do I have to do anything different to check total mechanical advanced timing?
I read the below from a link that Bill302 posted, real good information.
Ignition Curving
Here's one we see all the time. Did you know improper ignition tuning not only adversely affects performance, but it also can do permanent engine damage? Here's why: Ignition timing isn't just about aiming a timing light and getting 6 or 12 degrees BTDC timing at idle. What really counts is total timing and how it synchs with engine rpm. Total timing, meaning total spark advance in degrees of crankshaft rotation/position, should be completely in by 3,000 rpm.
As a rule, total timing should never exceed 36 degrees BTDC at 3,000 rpm and higher. Some people push the envelope and crank a few extra degrees in there thinking it will net us more power. But, when you dial in too much timing, you run a high risk of serious engine damage from detonation/spark knock. This happens when fuel ignition occurs too early on compression/ignition stroke.
The objective is to light the mixture at exactly the right time as the piston rises in the cylinder to where combustion is fully underway when the piston reaches top dead center. This hinges on fuel octane rating, ambient temperature, humidity, cam profile, chamber size and shape, air/fuel mixture, and atmospheric pressure (or pressure altitude). Every situation is different, which means no two engines will respond the same way to ignition curve. What works on your buddy's 302 likely will not work on yours.
And remember something else: Total timing when the engine isn't under a load is different than total timing with a load. With a load, you often need less timing because detonation typically occurs heavy load at wide-open throttle at low rpm. This calls for retarding total timing one degree at a time.
Engine Installation and Tuning Tips.
Typical total mechanical advanced timing at 4000rpms for Ford Racing Performance
Parts crate engines: 5.0L : 36 to 38 degrees
My timing is at 15 degrees advanced at idle with timing the spout disconnected.
I tried to check it to see if it was at 36 to 38 degrees at 4000 rpms and it still read 15 degrees. Do I have to do anything different to check total mechanical advanced timing?
I read the below from a link that Bill302 posted, real good information.
Ignition Curving
Here's one we see all the time. Did you know improper ignition tuning not only adversely affects performance, but it also can do permanent engine damage? Here's why: Ignition timing isn't just about aiming a timing light and getting 6 or 12 degrees BTDC timing at idle. What really counts is total timing and how it synchs with engine rpm. Total timing, meaning total spark advance in degrees of crankshaft rotation/position, should be completely in by 3,000 rpm.
As a rule, total timing should never exceed 36 degrees BTDC at 3,000 rpm and higher. Some people push the envelope and crank a few extra degrees in there thinking it will net us more power. But, when you dial in too much timing, you run a high risk of serious engine damage from detonation/spark knock. This happens when fuel ignition occurs too early on compression/ignition stroke.
The objective is to light the mixture at exactly the right time as the piston rises in the cylinder to where combustion is fully underway when the piston reaches top dead center. This hinges on fuel octane rating, ambient temperature, humidity, cam profile, chamber size and shape, air/fuel mixture, and atmospheric pressure (or pressure altitude). Every situation is different, which means no two engines will respond the same way to ignition curve. What works on your buddy's 302 likely will not work on yours.
And remember something else: Total timing when the engine isn't under a load is different than total timing with a load. With a load, you often need less timing because detonation typically occurs heavy load at wide-open throttle at low rpm. This calls for retarding total timing one degree at a time.
