Originally Posted By: Shannow
fredfactory,
it's SOP on a rebuild to run at a couple thousand revs for the sake of the cam rather than let it idle.
Look at the bottom line on the stribeck curve...the things that push you to the right are (more) surface speed and viscosity. The things that push you to the left are more load.
So, does this mean I warm up my engines in the best way possible?
When it's really cold out — near freezing or below — I generally sit in the driveway with the car in Park or Neutral, and steadily hold the engine at 30%-40% of its redline until it reaches normal operating temperature. (e.g. ~2.5k in a car with a 7k redline) Then I either drive away, or go back inside to let the cabin heater do its job. If I'm understanding you correctly, increasing the engine speed moves us right on the graph, while leaving the engine (relatively) unloaded keeps us from being drug back to the left in the process. Rightmost is where we want to be, yes?
So does that meant I'm warming up my engine the "best" way? If so, why doesn't the ECU just do this on its own? Because it freaks people out and makes their car difficult or impossible to drive for a few minutes until it's up to temp? Should I really be doing this
every time it's "cold" outside? (i.e.
I remember reading this tip in a shop manual, for mechanics who didn't want to stand around and wait for the car to idle up to NOT. I thought I read it in a Helm's, but I can't find it in mine, so maybe I actually read it in a dream…