2013 Ford Ecoboost Crank Reference for Timing values (VCT and injection timing)

[roastin300]

The trends I am seeing (mileage/efficiency, torque and driveability) are not following as I expect to see based on my understanding of the convention with how Ford references the VCt and injection timing....

POSITIVE values are AFTER TDC, and NEGATVIE values are BEFORE TDC correct?

For example, if the exhaust valve closing angle is +15 degrees then that is AFTER TDC, and the intake valve opening angle is -30 degrees then that is BTDC correct? That would imply an overlap of 45 degrees total (at whatever lift value that is in reference to)...agreed?

Injection timing varies from +370 to >+500 degrees....I am assuming this is in reference from TDC on the exhaust stroke? So +370 degrees would be 10 degrees ATDC on the intake stroke...agreed?

Thanks

[Puggyberra]

Injection timing varies from +370 to >+500 degrees....I am assuming this is in reference from TDC on the exhaust stroke? So +370 degrees would be 10 degrees ATDC on the intake stroke...agreed?

Thanks

That would be degrees after TDC of the compression stroke... if you subtract 360 you'd get degrees after TDC of the exhaust stroke. ie: 10->140 degrees after TDC of the exhaust stroke (or into the intake stroke). Ford desires a minimum of the injection time after injection is complete to allow for air and fuel mixture, most of that will be during the compression stroke (also while compressing your injectors are fighting the building pressure). So if you think of it that way starting 10 degrees ATDC of the exhaust stroke only gives them 175 degrees max for injection for their optimal mixture (and that's assuming spark isn't until TDC of compression). During maximum power operation they won't get that full double duration for mixture, but that's what the EOI Clip is. If EOI Clip was 600 degrees (stock F-150 3.5l value) after TDC of the exhaust stroke that would mean fuel could be injected until 240 degrees after TDC of compression stroke... or 60 degrees into the exhaust stroke as opposed to 60 degrees into the compression stroke. 600 degrees ATDC of the compression stroke puts you 120 degrees before the next TDC compression stroke, which is the same 120 EOI value in the 15+ ecoboost stock calibrations.

The valve timing doesn't necessarily follow the same reference though, from just glancing at it valve timing does seem to be based of TDC of the exhaust stroke.

[roastin300]

That would be degrees after TDC of the compression stroke... if you subtract 360 you'd get degrees after TDC of the exhaust stroke. ie: 10->140 degrees after TDC of the exhaust stroke (or into the intake stroke). Ford desires a minimum of the injection time after injection is complete to allow for air and fuel mixture, most of that will be during the compression stroke (also while compressing your injectors are fighting the building pressure). So if you think of it that way starting 10 degrees ATDC of the exhaust stroke only gives them 175 degrees max for injection for their optimal mixture (and that's assuming spark isn't until TDC of compression). During maximum power operation they won't get that full double duration for mixture, but that's what the EOI Clip is. If EOI Clip was 600 degrees (stock F-150 3.5l value) after TDC of the exhaust stroke that would mean fuel could be injected until 240 degrees after TDC of compression stroke... or 60 degrees into the exhaust stroke as opposed to 60 degrees into the compression stroke. 600 degrees ATDC of the compression stroke puts you 120 degrees before the next TDC compression stroke, which is the same 120 EOI value in the 15+ ecoboost stock calibrations.

The valve timing doesn't necessarily follow the same reference though, from just glancing at it valve timing does seem to be based of TDC of the exhaust stroke.

Ya thats what I was trying to imply is TDC...BEFORE the power/exhaust stroke. So I am referring it all correctly.

Thanks

[Higgs Boson]

Scan May 21, 2018 at 1.08 PM.jpg