engine acceleration rate data

[motorsportbeng]

Hi all,

I'm currently working on my University project write up. I'm doing a section on engine speed monitoring and I am talking about how engines can accelerate by a high amount of RPM in one crankshaft revolution. I would like to complement it with a physical example but I haven't found any data in my literature and haven't performed any dyno testing yet. Does anybody have anything to hand?

Thanks

[anonymous-user]

Peak acceleration on the crank these days is generally negative, and occurs during a transmission upshift, when the crankspeed is dragged down by the higher gear/road in about 50mS!

In terms of free-reving, where the engine is reved in neutral, an F1 engine can exceed 50krpm/s and a low inertia production based engine (touring car/rally etc) is arounf 20krpm/sec.

The difficult value to get hold of is the engines total rotational inertia, as once you know that, you can easily calculate the typical acceleration availble from dynamic firing loads etc.

[AER]

From my dim and distant past, a 2.0L Zetec measured about 0.12kgm² in total equivalent rotational inertia and a large chunk of that was (obviously) the flywheel/clutch assembly

[tristancliffe]

Our F3 data shows the rate of change regularly peaking at +-30000rpm/sec.