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Date: Tue, 11 Nov 2008 16:30:33 -0700
From: Bob White <bob@bob-white.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Oil Coolers - OFF TOPIC - hailing Lynn Hanover!
Message-Id: <20081111163033.b55b94a1.bob@bob-white.com>
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The way I was visualizing it, if you have a bottom inlet then you
would have a top outlet and vice versa.  I agree with what you are
saying, but suspect you might get better distribution through the
exchanger if the input were on the bottom.

I learned the ineffectiveness of plumbing a heat exchanger wrong with
the heater core on my old '52 Ford.  Since radiators outlets were on
the bottom and inlets on the top, I reasoned that the heater core
should be the same.  As soon as the water level in the system got a
little low (and it always did), the heater would only blow cold air.
After switching the hoses around, water going in the bottom would
always fill the core to the top outlet and the heater worked just fine
even with low water in the cooling system.

Bob W.

On Tue, 11 Nov 2008 18:00:32 -0500
"Thomas Jakits" <rotary.thjakits@gmail.com> wrote:

> Hi Bob,
> 
> thanks for your reply!
> 
> In both installations the oil-cooler is above the oil level by a good
> margin.
> 
> In my opinion the inlet position is not the critical issue, but the outlet.
> 
> As the oil slows down considerable in the inlet tank, it may (or not) loose
> the ability to push all the air out in front of it.
> If at the initial filling of the cooler after start-up (or opening of the
> thermostat) air gets trapped at the top of the cooler, this air never gets
> pushed out, just compressed to oil pressure values.
> With a top outlet, the air has no choice but leave the cooler through the
> outlet....
> 
> Am I way out there ?????
> 
> 
> thjakits
> 
> On Tue, Nov 11, 2008 at 2:46 PM, Bob White <bob@bob-white.com> wrote:
> 
> > Hi Thomas,
> >
> > If the oil cooler is below the oil level in the bike, I don't think top
> > or bottom inlet will matter too much.  If it's above the oil level in
> > the pan, then bottom inlet will ensure the cooler is always full of oil.
> >
> > My 2 cents and that's probably more than it's worth. :)
> >
> > Bob W.
> >
> > On Tue, 11 Nov 2008 14:27:00 -0500
> > "Thomas Jakits" <rotary.thjakits@gmail.com> wrote:
> >
> > > Hi all,
> > >
> > > I know this is a rotary and aviation list, but there is a lot of cooling
> > > going on here, so I just dare to ask a OFF TOPIC - no pics, so it should
> > > load quick too :)
> > >
> > > I would like to ask specifically* Lynn Hanover*, but if anyone else knows
> > > something too, please let me know!
> > >
> > > Hopefully soon I will start to restore my 79 R100S BMW bike.
> > > It does not have an oil cooler yet, but it will when I am done with it.
> > >
> > > My question regards the correct orientation of the cooler.
> > >
> > > To my knowledge ALL BMW airhead OEM oil cooler installations are with the
> > > connections at the bottom of the cooler.
> > > I have a mangled specimen off a GS at home - it seems to be a 6-row,
> > single
> > > pass cooler.
> > >
> > > I posted this question on ADV, but got no clear answer.
> > > I am  still waiting for a reply from one member who posted a reference to
> > a
> > > cooler manufacturer that says cooler orientation does not matter (in
> > > reference to the position of the connections .....)
> > >
> > > # My concern is, that if the outlet is at the bottom of the cooler, there
> > > may be a air cushion trapped in the upper part of the cooler - depending
> > on
> > > the oil pressure and heat, this may cause a significant loss of cooling
> > > capacity - question: Right or Wrong???
> > >
> > >
> > > Here the link to the post on ADV if you care to discuss (Beware, if
> > you're
> > > used to the polite, friendly and helping attitude on this list, you may
> > > encounter a somewhat different trend on other lists, ..... at times! ADV
> > in
> > > general is a great place, just now and then one encounters ridicule of
> > > varying degrees.....)
> > >
> > > http://www.advrider.com/forums/showthread.php?t=400352    ("Oil Cooler
> > > Orientation")
> > >
> > > All I really want is to confirm or refute my view!
> > >
> > >  Also, most "performance installations" Sport, Racing - seem to support
> > my
> > > suggestion - outlet on top....
> > >
> > > http://www.advrider.com/forums/showthread.php?t=328831
> > > http://www.advrider.com/forums/showthread.php?t=399841
> > >
> > >
> > > Any experience, data, tests  -   you guys/gals?
> > >
> > > Next question: Again orientation of the cooler.
> > >
> > > On this list I learned a lot about ducting. Obviously here we are
> > generally
> > > talking about 35-40 kts at a minimum or at least a prop blast on the
> > ground.
> > > On the bikes (I limit this discussion to BMW airheads) they are installed
> > > vertical in front of the engine or on the right side on top of a crashbar
> > in
> > > front of the cylinder.
> > > Generally there are no ducts - one had a "fairing" for optics at some
> > time.
> > >
> > > Check the following thread and you will see either installation at some
> > > point.
> > >
> > > http://www.advrider.com/forums/showthread.php?t=51879   (Plenty of GS
> > > installations right away, a center one is on a yellow bike nearly all the
> > > way at the bottom of the 1st page....)
> > >
> > >
> > > According to my wisdom gathered  on this list, either installation is
> > about
> > > useless:
> > >
> > > # Most of the cooling air would go around the cooler instead of through
> > > # Speeds are of course slower than with airplanes, but the cooling is
> > worse
> > > when standing still or in stop and go.
> > > # Cooling would be done mainly by radiation in this situation. Question:
> > > True/False?
> > >
> > > Question: Could cooling be improved in this stop/go situation by
> > installing
> > > the cooler at an angle (30-45 deg) so there would be some convective
> > action,
> > > once the heated air leaves the back of the cooler?
> > >
> > > I know, there is probably not much action.....
> > >
> > > My plan (pending replies...) is to have me a cooler custom welded (Ed
> > > Klepeis  ?), still need to guestimate the size: 2-pass, inlet at the
> > bottom,
> > > outlet at the top.
> > > Install with a 30 degree angle (top forward) and make a small alu-duct.
> > > Question how long should the the duct be at a minimum in front of the
> > > cooler?
> > > It will probably not be a real duct, but rather a guide - aesthetics are
> > of
> > > course of some importance on the bike!
> > >
> > >
> > > Any airheads on this list?
> > >
> > > Any suggestions?
> > >
> > >
> > > At the end my 100S lived its life without a cooler, but Austrian airs are
> > > way cooler than Panamanian, so a cooler she will get! :)
> > >
> > >
> > > Thanks for your time and suggestions!
> > >
> > > thjakits
> > >
> >
> >
> > --
> > N93BD - Rotary Powered BD-4 - http://www.bob-white.com
> > 3.8 Hours Total Time and holding
> > Cables for your rotary installation - http://roblinstores.com/
> >
> > --
> > Homepage:  http://www.flyrotary.com/
> > Archive and UnSub:
> > http://mail.lancaironline.net:81/lists/flyrotary/List.html
> >
> 


-- 
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
3.8 Hours Total Time and holding
Cables for your rotary installation - http://roblinstores.com/