Thanks Dan. I guess my question still remains is whether the vernatherm is working properly since my previous CC with it kept the oil temp at ~175 year round from oat of 20 to 105. Guess a call to ECI who makes it (??) is needed to see if this is the norm for the vernatherm to only keep it at ~155 now.
Jon
All my planes needed a control for airflow through the cooler to control oil temp. Vernatherm never kept it constant for me. Same on the cub, except this cooler is way to big. Half blocked off in summer and full in winter. I plan to build an airflow control like Dan has mentioned in the Cub now too.
Dan - Please keep me/us posted... I'm interested in your sliding shutter for the Oil Cooler.
FYI - I added two baffles (see Chuck & Ryan's Build Tips: Heat) in front of cylinders #1 & #2 (see pic), now all four CHTs are roughly in-line. Previously I was getting 70 degree deltas. With all four CHTs now running about the temps, and about 90% of my Oil Cooler taped-off, I'm getting ~180 degrees Oil Temp on 8C OAT days (61-65% power LOP).
IMG_1608.jpgIMG_1616.jpg
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Here I am milling out slots in the shutter.
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Here the shutter is installed and showing it in the closed position.
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And now in the full open position. Like this there is still about a 50% restriction compared to the original design.
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A push/pull cable on the panel next to the carb heat opens and closes the shutter. And a partially closed position can be selected too. I'll get a few hours on it with our current cold weather and see how it performs.
Flying Carbon Cub EX #11 since 2011
shutter_stationary.PDFshutter_slider.PDF
I'd been asked about what I made a few times so thought I'd just post everything. There are two .pdf drawings that can be clicked on and downloaded above. No doubt a few improvements could be made.
"I’ve attached the two drawings I have for the shutter. Those along with the images should help you if you decide to make one similar. A few things I should mention also:
I didn’t make a drawing of the arm but you can see how it fits – a simple part ˝” wide by 2.25” long, with rivet holes to attach to the slider part.
The stationary part has two #10 flathead screws coming through it from the oil cooler side. So the part is chamfered for the flatheads. A .250” dia. steel bushing slips over the #10 screws and the slider part rides on these. These also are the stops to end the movement each direction. The images are slightly different as I made a change here. Originally I had four of these with two more on the top side. But there was an interference issue with the plenum.
The plenum will need a minor notch filed into it to clear the arm. The oil cooler front/top lip will need a slot in it for the arm.
The bottom/backside oil cooler lip should be brought up with a shim the same thickness as the material used for the other parts to keep things from binding.
I think everything else is explainable in the pictures. Pretty simple."
Flying Carbon Cub EX #11 since 2011
No I didn't. I don't think blocking the rear would be very effective. Limiting air flow on the front side is the best IMO. The knob is identical to the black carb heat knob.
I did fly it today but as luck would have it I had a malfunction with my oil temp gauge. Back on the ground I found a clipped wire going into the back side of the EI gauge. A week ago I added a power point receptacle behind the panel and I must have cut this wire when I was cutting the tail off of a plastic tie. It was an easy fix though and next flight I'll get a good feel for a change in oil temps.
Flying Carbon Cub EX #11 since 2011
A flew for an hour and a half with the shutter in place and a working oil temp gauge today. With the shutter completely closed it raised the oil temp about 10 degrees over fully open. I'd hoped for more. But different power settings make more of a difference. It is more effective at higher power. The OAT was in the teens.
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Flying Carbon Cub EX #11 since 2011
Thanks for the update. Question:
- does this confirm that the oil is essentially bypassing the oil cooler and the vernatherm is working? With the oil cooler either 100% closed or open the temp only changes 10 degrees, no need to even tape it off?
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