hi again Curt!
Curt Raymond wrote:
If blocking the radiator made any significant difference in the overall temp of
the engine that would seem to indicate that the lowered temp were due to some
leakage past the thermostat wouldn't it?
i'm sorry if it still wasn't clear to you that i understand this
point. (again, like i repeated *again* below in the message you included
below) the fact is that blocking the radiator doesn't only block airflow
through the radiator; it also blocks airflow through the engine
compartment, and some heat is lost into the air moving past other things
in the engine compartment as well. i understand your point, and agree
that the limited point you're addressing is not relevant in the case
we're discussing.
The point I keep making and you seem to keep sliding around is that only
something like 20% (I did find one study that said 28% w/biodiesel and 29% with
petro) of the energy of the fuel, any fuel, propels the engine and the temp of
combustion is many hundreds of degrees so therefore the engine should be able
to get up to temp at temperatures above freezing...
i'm not sure which point you're referring to (since that's a run-on
sentence of the type i tend to be guilty of! ;-) ); i certainly wasn't
trying to "slide around" anything. while i agree with the first part of
that sentence/paragraph, i think the conclusion at the end is based on
an oversimplification that doesn't take into account all the differences
in fuels.
i've tried to make this point before repeatedly, but let me try to
summarize this again one last time yet another way: fuels aren't as
similar as you seem to be trying to present them. they don't ignite at
the same temperatures (there's actually hundreds of degrees difference),
they don't burn at the same rate, and they release different amounts of
heat (and at different rates) even relative to the energy they release
for use.
as yet another example, even variations in the stock BioD is made
from will produce fuels with different energy content, flash points,
ignition points, burn & peak power rates; you should be able to verify
this yourself in a variety of places. (though they don't all agree
exactly with each other, they all agree that there are differences.)
thanks anyway for your comments!
cheers!
e
I still don't understand it... Wish I could find some real testing that
confirmed/explained this. I did a search but came up empty handed...
-Curt
Date: Mon, 11 Jan 2010 15:26:01 -0800
From: ernest breakfield <erne...@backyardengineering.org>
To: Mercedes Discussion List <mercedes@okiebenz.com>
Subject: Re: [MBZ] running temps in the cold?
Message-ID: <4b4bb389.8080...@backyardengineering.org>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
hi Curt!
i don't know if i'd be playing with BioD in those conditions
either,... ;-*
(FWIW, i don't think carbon buildup is much of an issue with BioD.)
again, as long as there isn't enough heat in the engine to warm the
coolant up to where the 'stat opens, the temp rating of a 'stat isn't
going to make any difference.
again, blocking the radiator grill wasn't just to prevent the loss
of heat through the coolant, as there are other places where heat is
lost from the engine (like the oil cooler and the engine itself). it
would seem there's sufficient loss through those channels of what little
heat is generated by BioD that the coolant isn't reaching 'stat opening
temp.
i may try blocking the grill yet (at least partially, and/or with
something slightly breathable). temps haven't been low enough here
lately that i'd see any results that i think would be of interest as
they relate to the original question, and it's not forecasted to get
below 40?F here for at least a week.
cheers!
e
'85 300D
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