"these things is designed (not surprisingly) to expect the waste heat resultant
from running PetroDiesel"
This statement seems to neglect the action of the thermostat. The whole point
of the thermostat is to keep the engine at optimum temp. For bioD to result in
the engine running cold the radiator has to be ambient while the engine is
running (or just over, I'm sure theres some leakage around the thermostat). The
engine produces waste heat, the thermostat ensures a portion of that waste heat
is kept in the engine, the radiator wastes the rest out.
I can assure you its MUCH colder here than its ever been in Berkley and my car
has no problem keeping up to temp. In fact I realized today that when I said
80C I probably ment 90C, the needle generally rides right at the top of the 8
in 80, about halfway between the 80 line and the next one...
-Curt
Date: Tue, 05 Jan 2010 13:43:13 -0800
From: ernest breakfield <erne...@backyardengineering.org>
To: Mercedes Discussion List <mercedes@okiebenz.com>
Subject: Re: [MBZ] running temps in the cold?
Message-ID: <4b43b271.9080...@backyardengineering.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
hi Max!
i'll check the temps with a laser thermometer again, but haven't
found any real disparities in the past.
good thought about the airflow over the rad when there's no coolant
flow; but there's also the oil cooler, and all the heat lost to air
that's generally circulating around the engine compartment,...
by any chance are you running BioD? i think this is the main
contribution factor in this issue,...
i guess i wasn't clear enough that this seems to be most apparent in
colder weather when running BioDiesel; in more normal temps and/or on
regular #2 it's usually just over 80C where we'd expect it, varying to
occasionally right up around 100C on an extended climb in warmer
weather. this thing really seems happiest (read: more powerful, smoother
shifting) when it's warmer, and i was thinking there might be some
advantage to keeping it closer to its target temperature. (like more
power, better oil flow, better evaporation of crankcase water
contaminants,..).
i strongly suspect it's in a large part because BioD doesn't put out
the same amount of waste heat as #2; many others in the BioD fleet
around here seem to have noticed the same thing. the effect is even more
exaggerated with the W/SVO crowd. seems that the cooling systems in
these things is designed (not surprisingly) to expect the waste heat
resultant from running PetroDiesel, and the cooling system is
overcooling when running anything else.
am still really interested in hearing about the thoughts regarding
shrouding (like yours; good point again!).
cheers!
e
_______________________________________
http://www.okiebenz.com
For new and used parts go to www.okiebenz.com
To search list archives http://www.okiebenz.com/archive/
To Unsubscribe or change delivery options go to:
http://okiebenz.com/mailman/listinfo/mercedes_okiebenz.com
