Date: Fri, 24 Sep 2010 20:45:04 +0300
Reply-To: Janne Ruohomäki <janne.ruohomaki@GMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Janne Ruohomäki <janne.ruohomaki@GMAIL.COM>
Subject: Re: Coolant/Oil that oil filter interface.. reasons
In-Reply-To: <AANLkTi=+Csg2gNkwjz2mRjhv4DhOeXm21iQn88AdyPj7@mail.gmail.com>
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On Fri, Sep 24, 2010 at 5:08 PM, Don Hanson <dhanson928@gmail.com> wrote:
> I understand that many VW motors, some WBX included, have the oil
> filter/coolant heat exchanger like the one 'above' the oil filter that I
> found on my 93 Jetta (recent) transplant block. I just swapped this new ABA
> motor into my 84 vanagon in place of a 92 1.8liter inline VW. The
> 1.8l motor has no exchanger like that. Looking at this thing, it seems a
> bit....useless?
It seems a bit underbuilt, to me too.
> Is it supposed to 'cool' the oil? Heat the oil?
Both. I suppose.
> Up or Down to the temp of
> the coolant? That temp. is about 188f with an 87c
> thermostat...about normal oil temp anyhow. The temperature difference, as
> influenced by the coolant circulating around the oil filter pipe, is that
> same condition not present all over the motor?
It is a heat exchanger. It can do both, oil/air exchangers usually can
just cool. The more evenly the heat is spread through the engine, the
better. Those standard vanagon engines are probably not so prone to
damage due to cold engines, but I can imagine bigger straight 6
diesels can easily take considerable damage if the engine is punished
with high power when it is still partially cold. The whole engine
basically bends, when some parts heat up quicker than the others. That
high power output taken when the engine is still cold makes the
problem even worse by probably adding temperature differences by
heating up certain parts of the engine faster. Combine the previous
image with sluggish cold oil and just started engine where all the oil
has dripped down and sits on the oil pan as one big frozen chunk to
get the picture what an engine feels like when it is being started
from cold.
I live in area where it can be really cold during winter. I am
planning to upgrade my oil/water heat exchanger to bigger one. That
combined with remote controlled webasto and electrical aux water/oil
pumps will give me evenly heated engine in no time every winter
morning. Oh.. and mine is going to be turbo diesel. I would assume WBX
engine could actually be a bit more demanding on the oil temperature.
Dont really know, just a hunch. I dont think they went with that
complex WBX oil pressure warning system just for kicks.
I would assume that the oil in the engine makes closer friends with
the hotter parts of the engine than water.
> As coolant circulates
> through the head and block, it shares the same contact with the metal as the
> oi/ in adjacent passeges, right? Is there a real advantage to adding that
> extra small 'interface' at that "cooler? Heater?" ...whatever you would call
> it? It looks like there might be very little thermal exchanging going on
> there, between the oil and the coolant, given the surface areas involved.
I think exiting oil is quite a bit warmer than exiting water. Havent
really measured, but Im sure someone can confirm or deny?
> My 1.8 liter without that type exchanger had no issues whatsoever
> involving oil temps in the 60k hard hard miles I put onto it..
What does it mean when You say "no issues" ? Do you have oil temp gauges ?
> Just curious..any body else have an opinion or give a darn about this
> little widget?
I like them. Generally that is. I am prepared to take the extra risk
of mixing oil and water in the engine due to leak in this extra
complexity. Its still passive part, no electrons involved and no
moving parts. Certainly it can be made to outlast the rest of the
engine with modern technology ? I also like simple things. Properly
built oil/water heat exchanger is one of them.
> PS...I am leaving mine on there, for now, without any coolant circulating
> through. I might sometime hook it up and monitor the oil temp...see what
> happens in the motor...I bet Not Much..
Maybe not much. Might still matter, at least in the long run. Double
the size and test again on highway speeds during summer. And do
measure the cylinder head temperature also.