Re: Warm up times (Was: long distance repair)...

[Alex Kowalski (audial@aol.com) (Law Guest Account) <lawguest@wppost.depaul.edu>]

Just shooting from the hip here, but I imagine a lot of things influence the
warm-up time, right down to the finish on the engine castings.  Some
types of surface finish radiate heat much more effectively than others (I
don't have the Bosch metallurgy primer with me, but the differences can
be very large).  

Other things I can think of include the volume of the internal water
jacketing,  the capacity to transfer heat from the exhaust manifold to the
head and/or block,  the amount of oil in the sump and its rate of circulation
through the engine, and how much metal (and which types) there is in the
engine relative to its displacement.  My guess is that relatively compact
motors with large displacements for their physical size will warm up more
quickly.   Also, mixture distribution at idle when the engine is cold will
surely affect the engine warm up.  If the fuel condenses on the inside of
the manifold (obviously not talking about port FI here) you're obviously
going to get some evaporative cooling taking place.  My small block Chevy
had exhaust heat-riser passages cast into the (_heavy_, cast-iron) intake
manifold in stock form because in cold weather most of the fuel would
spritz out of the carburetor jets and condense on the IM walls and form
puddles of fuel in the IM.  Not exactly a good thing for equal mixture
distribution.   You can block these heat riser passages off for more
performance when the engine is warm, but then the car becomes a real
SOB for the first 5-10 minutes when it's cold outside, if you can get it
started without fouling the plugs in the first place. 

Thank God for fuel injection.

Automobiles seem so simple, but they are fractal-like in their complexity.

Pardon me, but are we as a List just a little crackers for caring about
these issues as much as we do?  


Best Wishes,
Alex