X-Mozilla-Keys:                                                                                 
Mike Wills wrote:

Paul Lamar Wrote:

I am wondering lately if the oil water heat exchangers used by some that
are flying are really worth while. I for one will not bother and
merely use oil coolers. Probably two of Earl's supply rectangulars
fitted in the same cooling duct. The issue is coolant plumbing.
I don't want to use radiator hose so ridgid aluminum pipe with
wiggins fittings are my preferred choice. To complicate matters
by diverting some coolant flow to a oil water heat exhanger
may be more than most people want to address.

Paul Lamar

Paul,

 Who is successfully flying an oil/water cooler that is actually working as
the sole means of oil cooling? No one to my knowledge. But I can sure see
the advantage in reduced undercowl ducting; particularly if using a
radiator with the cooler built into the radiator tank. Then there are no
extra coolant lines/connections required.

As I recall Jim Mosur had something working as well as Andy Venable.
Both are on the list.

 The most successful cooler installations that I'm aware of use the stock
Mazda cooler mounted crosswise below the spinner with core perpendicular to
the airflow. This is Jim Mosur's config and also Ed Anderson's config after
giving up on his Earls cooler. Unfortunately the stock cooler doesnt fit in
the skinny RV-4 when mounted in this config. Other mounting configs using
the stock cooler have been less successful. Not to say it doesnt work -
just less successful than Jim's and Ed's.

 In my opinion the best possible config (theoretically from a space and
reliability standpoint) is the radiator with built in cooler. It offers
reduced connection  and  ducting requirements. I had previously ruled out
using one of these as I didnt believe it would fit. Im slowly becoming
convinced by both you and Fred that a large radiator can be located
horizontally under the engine and will be functional with a proper
diffuser. I'm still skeptical about how a proper diffuser (as I understand
the definition of a proper diffuser) can be built in the limited space
available under my cowl. Fred is continuing to assist me in this.
 The radiators with built in oil coolers are available from Fluidyne (among
others) who Ive mentioned here previously.

Mike Wills

I am building a variable or moveable wall 2D diffuser as we speak.
It may be a few days before I have results to share but not
to worry. I anticipate only a simple curve will even up the
flow through the rad. Jim Mosur has no curve. Just stright 
wedge shaped ducts and his is cooling well. I need
to order the air speed meter Fred mentioned.

Some others have the crudest sheet metal scoops and ducts 
imagineable and they are also cooling well if not providing 
low drag.

Paul Lamar
 
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