When do you plug them in?

[Thomas]

Depending on the temps..
32F to 15F couple of hours,and colder 8 plus hours before use..and I do believe keeping a tractor out of the weather elements improve cold weather starting when setting for a peroid of time.

 

[MikePA]

<font color="blue"> Starting a frozen diesel engine is about as hard as getting me to like some of the guys who come calling on my daughter. Now if she warms me up by telling me he is a good student, on the deans list, and has a chance at gainful employment then I might not be cleaning my shotgun when he shows up . . . </font>

Bob and Bob, I stand corrected...and with this analogy, as a father of 2 daughters, how could I disagree! /forums/images/graemlins/grin.gif

 

[John_Mc]

Bob -

I've no argument with you description of why the heaters help with starting a diesel. (Though the effect on starting may be greater on the big truck engines, compared to a 20-40 HP tractor engine).

I do know, however, that preheating a cold engine prior to starting greatly increases its life. I've read in several places (unfortunately, I can't remember any of them now, unless you count my book on operating piston aircraft engines) that the majority of all wear on an engine happens in the first few moments after startup. The wear occurs due to the fact that many of the metal parts are "dry" at this point. In cold weather, the effect is worse for two reasons: (1) it takes longer for the cold oil to flow into all the places it needs to be, and (2) the clearances are tighter on a cold engine (even more so on engines which use a mix of aluminum and steel parts, since they have different coefficients of expansion). Taken together, this means more friction and wear on a cold engine due to the tighter fits, and for a longer amount of time than in warmer weather.

Which effect is more important? Who knows. But both are good reasons to pre-heat in cold weather.

John Mc

 

[Bob_Skurka]

John your points are absolutely correct from what I've read, and I can't remember the sources either!

Any way you cut it, starting a warm engine is better for the engine and easier to start too.

 

[PineRidge]

I might suggest to all those planning the use of block heaters to wrap the extension cord around the steering wheel a couple of times before you plug it in. It will help you to remember to unplug the contraption before you drive the tractor off dragging your pole barn behind you. /forums/images/graemlins/frown.gif