engine rpm at idle

[WHN]

I prefer a low idle, it allows for easier shifting of gears when under way.

I also do not let the car idle for any extended length of time.

If everything is correct with your cars engine and it is timed properly, that slow idle should be there. You can adjust up from that point at the carburetor or at steering column.

 

[Bob Bidonde]

In showing off a very slow idle as a characteristic of a good running engine, my concern is metal-to-metal contact in bearings may occur for 2 reasons:
1. Hydrodynamic pressure gets too low because of low speed in the bearings;
2. Inadequate oil supply to the main bearings, camshaft bearings and connecting rod troughs. So showing off a very low idle speed / lugging the engine in too high a gear may reduce the oil pumps output to an intolerable amount.

Consequently, I keep my engines idling high enough so you cannot distinguish any fan blades; they are a blur. I also downshift to keep the engine RPMs up when turning corners, climbing steep hills and in parades.