Date:         Thu, 18 Aug 94 11:11:19 PDT
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         David.Kao@Eng.Sun.COM (David Kao)
Subject:      Re: engine temperature

The cooler the better? I have seen many postings talking about oil/coolant
temperature. It seems that everyone thinks the lower the better regarding eng
temperature. However, I think I should bring up a different point of view
from a book I read about. It probably worths some discussion here.

The book revealed a fact that is quite different from common sense of most
people regarding engine temperature. It showed a graphic of engine temperature
vs. cylinder wear. The graphic showed that the lower the temperature the 
more the wear of engine cylinders. The curve finallly leveled when eng temp
reaches a certain point.

The book also pointed out that this is easily proven by inspecting an engine
awaiting for rebuilding. The first cylinder right behind the radiator (where
it receives most cooling air from the cooling fan and thus is the coolest 
cylinder) has more wear than the fourth which is the hottest in pretty much
all cases. I looked at my old 71 BMW2002, yes the first cylinder obviously
has much more wear than the rest.

I think this is the reason why you need to warm up your car in the cold morning
days before drving it. Besides, you want your car to warm up fast. And you
want to have higher antifreeze/water ratio so that engine runs a little hotter.

For air cooled buses, the thermostat should not be altered to lower the eng
temp. It might does the opposite to the engine.


David Kao