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  #1  
Old 10-19-2017, 11:43 AM
N729LS's Avatar
N729LS N729LS is offline
 
Join Date: Apr 2015
Location: Mesa, AZ
Posts: 181
Default Very slow oil warm-up?

I have recently acquired an RV-8 with an angle-valve IO-360. At lower OATs (below 60?F?), I find it takes inordinately long to get the oil temp up. I prefer to get up to 150-160?F, especially when doing formation TOs that require lots of throttle jockeying. At those temps, I'm seeing 90-100 PSI at 2700 RPM. Temp regulation in flight appears to be normal and cruise numbers for temp and pressure are good.

SO... I thought I understood the operation of the Vernatherm valve. But to more expert guys - Is there a failure mode of the Vernatherm that would not bypass the cooler at lower temps, ie. always have the oil cooler in the circuit? (At home base, I know I can install and use a sump heater, but sometimes when out X/C there is no power available.)

Thanks,
Andy Elliott
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  #2  
Old 10-19-2017, 12:09 PM
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Carl Froehlich Carl Froehlich is online now
 
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Location: Dogwood Airpark (VA42)
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Default

The vernatherm valve system always provides oil to the oil cooler. When oil temp is low, the valve opens allowing a bypass line around the oil cooler in addition to some oil still going to the cooler. It does not stop flow to the cooler, just reduces it.

I installed a butterfly valve to control cooling air to the oil coolers on both the RV-8A and RV-10. Even at OATs in the 70s I need to close down the oil cooler air a little to keep oil temp at 180 or so in cruise.

Carl
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  #3  
Old 10-19-2017, 01:14 PM
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Raymo Raymo is offline
 
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I have 1/3 of my cooler blocked off in the summer to get the oil temp > 180, which should be your minimum target temp.

Temps here the other day were in the low 70s and my oil temp only made it to about 175 in a 30 minute flight. Planning to install a slider mechanism for a more permanent solution that I can control from the cockpit.

That pressure is a bit on the high side and can be adjusted. When high, it might increase the amount of oil going through the cooler.
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RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, Dual PMags, Vetterman Trombone Exh, SkyTech starter, BandC Alt (PP failed after 226 hrs)
Catto 3 blade NLE, FlightLines Interior, James cowl, plenum & intake, Anti-Splat -14 seat mod and nose gear support
All lines by TSFlightLines (aka Hoser)

Last edited by Raymo : 10-20-2017 at 09:16 AM. Reason: clarification
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  #4  
Old 10-19-2017, 02:11 PM
gasman gasman is offline
 
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Location: Sonoma County
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Quote:
Originally Posted by Carl Froehlich View Post
The vernatherm valve system always provides oil to the oil cooler. When oil temp is low, the valve opens allowing a bypass line around the oil cooler in addition to some oil still going to the cooler. It does not stop flow to the cooler, just reduces it.

I installed a butterfly valve to control cooling air to the oil coolers on both the RV-8A and RV-10. Even at OATs in the 70s I need to close down the oil cooler air a little to keep oil temp at 180 or so in cruise.

Carl
I did the same thing on my 6A.... Using Phillips X/C, I have no high pressure problem when cold. But the oil took forever to heat up.
I installed a butterfly valve on my firewall mounted cooler. When I start up, the cooler is fully blocked. In cruse it is easy to set the oil temp just where you want.

The EMS won't let me forget to adjust it.
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  #5  
Old 10-19-2017, 03:28 PM
David-aviator David-aviator is offline
 
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The flow to the cooler is always open.
The vernatherm opens and closes the port to the engine depending on temperature.
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  #6  
Old 10-19-2017, 04:27 PM
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DanH DanH is offline
 
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Oil cold: Flow is through both the cooler and a cooler bypass port, in parallel.

Oil hot: Flow is through the cooler alone. The tip of the vernatherm closes the bypass port.



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  #7  
Old 10-19-2017, 04:40 PM
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N729LS N729LS is offline
 
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Thanks, everyone, for the input. My oil cooler is mounted on the baffling behind #4 cylinder, so the butterfly valve won't work. I am concerned that the shutter (slider valve) from Van's closes off a good part of the airflow even when open. I'm based in Phoenix, and from May-September, we need all the cooling we can get! Guess I could just remove it in the summer. I'll check the part number to see if it's the right one for the shutter to fit.
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  #8  
Old 10-20-2017, 09:14 AM
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Raymo Raymo is offline
 
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Quote:
Originally Posted by N729LS View Post
Thanks, everyone, for the input. My oil cooler is mounted on the baffling behind #4 cylinder, so the butterfly valve won't work. I am concerned that the shutter (slider valve) from Van's closes off a good part of the airflow even when open. I'm based in Phoenix, and from May-September, we need all the cooling we can get! Guess I could just remove it in the summer. I'll check the part number to see if it's the right one for the shutter to fit.
Please let me know if you find a part number. I thought Vans stopped selling the shutter/slider valve.
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RV-7A - Slider - N495KL - First flt 27 Jan 17
O-360-A4M w/ AFP FM-150 FI, Dual PMags, Vetterman Trombone Exh, SkyTech starter, BandC Alt (PP failed after 226 hrs)
Catto 3 blade NLE, FlightLines Interior, James cowl, plenum & intake, Anti-Splat -14 seat mod and nose gear support
All lines by TSFlightLines (aka Hoser)
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  #9  
Old 10-20-2017, 09:43 AM
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N729LS N729LS is offline
 
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Location: Mesa, AZ
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It is still listed in the .pdf 2015-2016 parts catalog as "EA Oil Cooler Vent", but does not appear in the on-line parts listing. Guess I'll have to invent something. Anyone already done that and able to provide a picture/drawing??
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