19 Oct 1997 10:57:51 -0700
Robert Harris 
Subject: RE: rad and coolant
Sender: owner-diy_efi

I borrowed a book from Dave Williams, now overdue and on the way back  - I
promise! by Century published in the 60's that explains graphically wear and
temps and why a fast warm-up is critical.  This is the results of a 60 hour
Gasoline Engine Test on a small industrial motor


Temp        Cyl wear        Fuel Consumption          Power
40  f         .008 in          3.8 gal/hr             26 hp
00  f         .002 in          3.5 gal/hr             27.2 hp
140 f         .001 in          3.2 gal/hr             28.5 hp
160 f         .0005 in         2.9 gal/hr             29.0 hp
180 f         .0003 in         2.8 gal/hr             29.5 hp


"F. Thermostats

The thermostats function is to retard coolant flow through the radiator until
coolant temperature increases to operating range.  A cold engine does not
provide the best performance  and is subject to shortened life and sludging.
More than a gallon of water is formed as each gallon is burned.  In cold
operating engines a portion of exhaust gasses and water blows by the piston
rings and forms corrosive acids in the crankcase.  This contamination is
greatest in wintertime due to retarding of the crankcase ventilating system by
low air temperature and increased warm-up time"

Moral of all this is to bring the engine up to operating temp as fast as
possible to minimize wear.  If electric fans, don't turn them on until
operating temp.   If you can control matters (EFI can on most engines) get it
warm (~180) as fast as you can.    At the right temp you make more power and
get better economy.  A note about oil.  Seems to lubricate best at about 180 f
average and somewhere it MUST exceed the boiling point of water on an open
surface in order to drive the water out.  If you don't, all the water makes
sulfuric and nitric acid in your oil and all the wonnerfull things that follow.