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
>