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Oil Cooler location

Depends...

Where is the best location for the Oil Cooler on a RV-4?

Hey Sully,
The original RV4 plans show the oil cooler mounted on the left rear aft side of the engine baffling. MANY iterations of that mount have appeared over the years including my own Four I started in 89'.
During my early test flights with a 6 row cooler mounted there I could never get the oil to cool inflight below 210F and would approach 230 in the climb. I replaced mine with an 8 row Positech cooler, switched to #8 size lines and relocated the cooler to underneath the forward left inlet baffle with a small scoop/lip. It required long oil lines (I had made at NAPA) similar to Cubs and Tri-Pacers but works very well there to this day, 27 years later.
Several other iterations I've seen I liked were the left rear baffle with a shroud allowing it to angle back 30 degrees. Another is a lower firewall mount with a 3" Scat from the baffle.
The real secret is getting your cowling to "draw" the air thru rather than trying to push it thru. On mine with the Vetterman 4 pipe filling much of the exit area I had to trim 2" off the lower lip.
Good luck, email me offline with any questions!

V/R
Smokey
[email protected]
 
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Left AFT baffle

I built all my baffles without the VANs kit because of my engine choice (O320H2AD) and put my oil cooler on the left baffle. I did use .063" material for the mounting section and added a diagonal stiffener to both sides. Works very well and zero cracks after 400 plus hours. Baffle building is its own little project, and when done correctly, results will be lasting with few problems.
 

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Has anybody tried cutting in a NACA duct on the side of the cowl, and use that for the oil cooler air? I was thinking that the 3 inch scat tubing from the rear baffle may be robbing air from the cylinders and perhaps you could cool the CHTS better by not taking air from the baffles? Perhaps there isn't enough pressure from a NACA duct though. .
 
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Has anybody tried cutting in a NACA duct on the side of the cowl, and use that for the oil cooler air? I was thinking that the 3 inch scat tubing from the rear baffle may be robbing air from the cylinders and perhaps you could cool the CHTS better by not taking air from the baffles?

I guess the "trick" is to figure out the best spot.
We all know how well those NACA vents on the canopy skirt work (not!!)
 
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Don't know the answer

I copied someone else on the mount and have an oil cooler shutter sandwiched against the top side. It leaves room to work on the left magneto for removal, adjusting timing, etc. Heavy aluminum angle bracket bolted into the top edge of the redder peddle well. Here in the northwest during most of the year the oil temp can be adjusted above and below the Lycoming specification. Attaching to the back of the baffle is a clean install too, and probably the same amount of work. Sorry for out of focus - these are the best log images I have.
 

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@Brian Vickers

Nice installation and very clean looking workmanship.

Is that a control cable installed to allow you to move the louvers from the cockpit?

Someone's going to mention the lack of safety wire on the filter. I know there's debate but someone was going to mention it.

If you'd let me/the forum know about the suspected louver control, it would be appreciated.
 
Oil cooler RV-4

cooler1.jpgcooler2.jpg

Hopefully the pictures attached and show my RV-4 oil cooler location. Originally I had the cooler mounted a couple inches higher on the firewall so the cooling air was more of a straight shot into the cooler airbox. When I went to the spline drive alternator I had to reposition the cooler for alternator clearance. Summertime oil temps are consistently 190-92.
 
Resurrecting this one. Hoping to get an answer.

@Brian Vickers,

Is that a control cable installed to allow you to move the louvers from the cockpit?

If so, is this typical of RVs?

Would appreciate your experience here.
 
Oil cooler shutter control

Freesmasm,
The shutter is in flight push-pull cable controlled from the cockpit. The control cable can be seen in the overhead view photo. There's a piece of blue masking tape on the end of the control cable wire. It gets used on every flight to stabilize at 180 degrees. In the winter I close it upon start-up to increase the oil temp faster prior to departure.
 


Here's is where I put mine, about the same as Brian's. Cooler was originally on a Piper Apache. If anything it cools too well. I have to partially block it off in the winter. I need to install a shutter.

Skip
NC
O-320 160 hp
Sterba prop
 
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