Cam/ignition settings for easy cranking

[blackbolt22]

Tried some overlap at idle on a friends 2018 Mustang GT. It ran decent so tried different amounts of overlap. A few of those times it struggled to crank over (like battery going dead) or like when ignition timing is too high on an old distributor car....

I'm assuming the Cam Phasers return to home mechanically. If the car killed on it's own from running rough, could that have caused phasers not to return to home in time?

Are there any settings in the tune either with spark or cams to adjust to make cranking over easier or is there no control because it's mechanical?

[Mustang]

This might sound crazy, but perhaps the battery is going bad? I don't say that sarcastically because I know a battery should last longer than that, but for whatever reason, the stock batteries are garbage. It happened to me and even after running it on a good quality charger (Noco Genius) to try and desulphate it, it wouldn't run right and sometimes failed to start. Perhaps get the battery load tested? I would think with more overlap, the dynamic compression should be lower and make it easier to start.

[murfie]

The intake cam controls the effective length of the compression stroke. Advancing it(more negative numbers) advances when the intake valve shuts making it longer( more compression). Retarding it(0 or more positive numbers) retards the valve shutting and shortens it(less compression).
The exhaust cam does the same thing, but for the effective power stroke power stroke. So with more overlap, advance intake retard exhaust, you have longer compression and shorter power stroke. more work being done and getting less return from the "air spring effect" making it less efficient and more work needed rom the starter.

The phasers return to base mechanically(no oil pressure to push them), hence why ford switched to the midlock phasers. To get more compression quicker with a more advanced intake cam. They dont have one on the exhaust as the most advanced position is ideal for starting with an advanced intake cam.

Try a new battery, or a new starter.

[blackbolt22]

As I made adjustments to the amount of overlap it changed the amount of 'struggle'. At the end, putting settings back to stock and it cranked up easily again. Checked battery voltage during all of that and it was strong. When the car suddenly killed from a low rpm dip, was when it did it if I remember right, like it didn't have time to go back to home position so the next crank was hard. During one of those times I didn't change anything, just killed it while around 1500rpms and cranked again, started fine.

If it is the battery or starter, it doesn't act up without overlap.

[superman07]

Do you even have enough fuel pressure at cranking to unpark the cams?

I think on mine VCT is disabled until 400rpm.

yes these batteries are shit.

[superman07]

I think valve tension would park the phasers no matter when the car died.

[murfie]

https://www.youtube.com/watch?v=Lujj...arnerCorporate

MPL is independent of oil pressure, so no I dont think an un expected stall when struggling would change the crank position of the intake cams.

The fact that BorgWarner also came up with dual position lock phasers, mid for cold start and end for hot starts, solidifies my thoughts on the cam returning to MPL when the engine is not turning. If Ford switches to those hopefully we will see the tables that control it in HPT.