Neil, I feel the same way. It's borderline at 200 cub inch for me with this heat. I'd be fine flying in Canada vs Florida. With time and better cowl design / streamline, I think I can get it to work better. But right now, I might have to look for something closer to a new rad in 250 cub inch range.

Charlie, I changed the video from private to unlisted. Sorry for that. I also believe it's the same size of Tracy's. We figured if it can cool a 20B, it should cool a 13B. BUT I know my cowl design / inlets are not streamlined to perfection like his is. I monitor both the oil pan and inlet. Yes the oil pan is the hottest, which is why I want to monitor it. Conventional oil starts to break down at 250F. Synthetic will go well into the 300s. Then I monitor the inlet temperature because that is critical to the engine. Racing Beat says 205 inlet but that seems pretty conservative. My personal opinion is you atleast want the oil to hit 220+ during takeoff in the pan to burn off any water. Then come down during cruise.

Bobby, I have a digital manometer with tubes and a home hvac one with a fan to measure pressure. Say the leaf blower was 40kts at the inlet, I'd get around 9kts at the front of cooler to 6kts at the back. Crude testing right now, but no dead spots. In the air, playing around 120-130kts IAS. 

Steve, perfect. I think I'm going to get that. Then as I narrow down on tinkering, I can try to fine tune my cowl to get the CX racing oil cooler to work for better speeds.

Mat,

            I feel that it is simply size that is the problem.  I have run 2 sizes,  First was 300 cub inches and then I cut down to  just over 250 cub inches.  The bigger worked very well, so I cut down in the next install due to size.  It still cools  well but borderline, so hoping it will handle the turbo??     Here 85 degrees is very cold, so my suggestion is to upsize the cooler size—sorry more work but that is simply my opinion.

Neil;

 

From: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Friday, May 14, 2021 7:01 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Oil Cooler sizing

 

I'm trying to tackle the oil cooling. Currently have a CX racing 11x9x2 (https://www.cxracing.com/oil-cooler-kit/OC-248-30-AN10)

 

On a 30C / 85F day in FL @ 2200rpm cruising

Coolant is 180 outlet / 170 inlet 

Oil is 225-230 pan / 200 inlet / 215 PSRU. 

 

I use Valvoline VR1 20W-50 standard oil, and have synthetic sitting on the shelf ready to go. Since we can't post much in pictures here, I put a video on youtube of the setup. The cowl inlet is 4" and the opening to the start of the wedge is 3". I added some turning vanes to help the wedge shape send more air to the front, but didn't change the temps too much.  

The only thing left to do is increase the opening on the wedge. I could probably get away with a 5" opening. If that doesn't work, then time to source out a bigger rad. What sizes are you guys running?

https://www.youtube.com/watch?v=ONO4bJvw5rc

- Matt Boiteau