Starter Torque

[hazmat]

<font color="blue"> It's gotta be the varying frictional coefficent of different metal chrystalline lattice form contact boundary layers subjected to thermodynamic pressure that make the difference Nomad. </font>

Egon,

You're making me re-live my tribology class from college. /forums/images/graemlins/confused.gif /forums/images/graemlins/confused.gif /forums/images/graemlins/shocked.gif

 

[Egon]

Think it means friction between different metals but actually it's just buffledust Hazmat.

Egon /forums/images/graemlins/grin.gif

 

[R_squared]

Here is the starter current waveform for a 1980's SAME #35, 2 cylinder, 1810cc diesel engine. The compression ratio is 17:1. This engine is direct injected. The inrush current for this 2 cylinder, 1810cc diesel is nearly equal to the 4 cylinder diesels inrush current. I captured two starting current waveforms and will post both to show you how reproducible the measuring methodology is. Any comments?

 

[R_squared]

Second SAME waveform.

 

[_RaT_]

Rather then even consider in rush or stalled rotor current, I think looking at the current while turning an engine over for 5 or 10 seconds would be the most beneficial measurement. Stalled rotor and in rush current can be explained simply by the design of the electric motor, the same can be said while the starter is running, but to a lesser extent. All things being equal, temp, battery and starter, a 10 second crank on a non startable engine should help evaluate the engines resistance to rotation. That of course would be difficult at best since rarely do 2 different engines share identical starters. In rush current for an electric (120V) light bulb can exceed 100 amps since in effect, the filament is a dead short. Not until it heats up does the resistance develop. That amount of time is in the 1/1000's of a second and thus never realized by the service suppyling it. I found your charts interesting and credit you for all your work, it is interesting. Rat...