REFLECTOR: First flight

Grover McNair grover at mcnairperformance.com
Sun Jun 10 20:20:46 CDT 2012


Having raced Mazda rotary engines for about 20 years I respectfully disagree with the idea of not being concerned with the max temp of the oil. Rotaries cool as much with oil as with coolant. Keeping the oil outlet temp below 230 was always best for engine longevity. I support the comparison to coolant temp sensing.
I would put the oil coolers in series. Any fluid will follow the path of least resistance.
Grover McNair

Sent from my iPhone

On Jun 10, 2012, at 3:24 PM, Chris Barber <cbarber at texasattorney.net> wrote:

> Wow, thanks guys...funny, I get to a point that I think I am pretty versed and then new info (well, new to me) come in.  It should not be too difficult to add a sensor to the oil going into the engine after the coolers.  Thanks.
>  
> Chris
> From: reflector-bounces at tvbf.org [reflector-bounces at tvbf.org] on behalf of Al Gietzen [alventures at cox.net]
> Sent: Sunday, June 10, 2012 2:12 PM
> To: 'Velocity Aircraft Owners and Builders list'
> Subject: Re: REFLECTOR: First flight
> 
> Chris;
> I agree with John. Engine out temp on the oil can be 250F without worry.  If you have unused channels of the EM; rig a TC at the outlet of each cooler, then you'll know the delta T on each and if they are considerably different you can consider restricting flow to the one with the low delta T.  They don't need to be the same, but you'd like the higher delta T to be less than about 50F for best overall cooling. Will also indicate oil temp back to engine; which may suggest you really don't have an issue.
>  
> You can rig a TC to a metal line with a hose clamp and a pad of insulation between clamp and TC; TC junction against the line.
>  
> Al
> -----Original Message-----
> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of John Dibble
> Sent: Sunday, June 10, 2012 11:36 AM
> To: Velocity Aircraft Owners and Builders list
> Subject: Re: REFLECTOR: First flight
> 
> Ahh.  There's your problem.  You should be measuring the temp of the oil going into the engine from the coolers.  So you oil wasn't as hot as indicated.
> 
> John
> 
> On 6/10/2012 1:12 PM, Chris Barber wrote:
>> 
>> Maybe, but both get hot.  I am taking the temp reading as it is coming out of the engine at the filter.
>> From: reflector-bounces at tvbf.org [reflector-bounces at tvbf.org] on behalf of John Dibble [aminetech at bluefrog.com]
>> Sent: Sunday, June 10, 2012 12:57 PM
>> To: Velocity Aircraft Owners and Builders list
>> Subject: Re: REFLECTOR: First flight
>> 
>> Hmmm.  With the coolers in parallel, how do you know where the oil is going?  Seems like it will take the path of least resistance.  Maybe one cooler isn't doing much?
>> 
>> John
>> 
>> On 6/10/2012 8:34 AM, Chris Barber wrote:
>>> 
>>> I have two oil coolers already.  The standard cooler mounted under the aircraft laid flat with the radiator to make one large unit and fed with a large ram air scoop on the bottom of the cowl.  I also have a second oil cooler (standard aircraft cooler as  provided by Velocity) in the nose per planes plumbed in parallel.  It was originally plumbed in series but since it has smaller fittings, it was causing a pressure issue and oil would seep out from around my oil filter.
>>>  
>>> I got some pondering to do.
>>>  
>>> I was just looking at the distorted video I took while in the pattern on downwind.  It is only a few seconds long.  Very hard to see some of the info.  It does show my rpm got up to 6870 rpm but the map on the RWS monitor was only indicating 24.7. (?)  I am running a spring in the waste gate at 1.5 lbs. Coolant temps were 187 degrees while oil was 224 degrees.  GPS speed showed 128 kts per the Dynon. 
>>>  
>>> The IVO in-flight adjustable prop was at full fine. The IVO pith range is 45 - 105 and IIRC it is 68 inches.
>>>  
>>> Chris
>>> From: reflector-bounces at tvbf.org [reflector-bounces at tvbf.org] on behalf of John Dibble [aminetech at bluefrog.com]
>>> Sent: Sunday, June 10, 2012 7:27 AM
>>> To: Velocity Aircraft Owners and Builders list
>>> Subject: Re: REFLECTOR: First flight
>>> 
>>> I second that for the oil cooler.  Are you using the standard oil cooler?  I think a problem is that the standard oil cooler is intended for engines in the 180-200 hp range and for engines with more hp, a larger cooler is needed.  It doesn't take much increase in cooler size to make a big difference in cooling, so a larger cooler (1" taller) may be all you need and simpler than adding a second.
>>> 
>>> John
>>> 
>>> On 6/9/2012 8:28 PM, Al Gietzen wrote:
>>>> 
>>>> Way to go Chris!!  That is a life-changing milestone.  Congratulations!
>>>>  
>>>> Reminiscent of 1st flight with my plane - oil temp hit 225 and ended the flight with one turn around the patch. As you said; not critical, but you  don't want to run a rotary very long above that temp.  For me it took some work on the scoop; and eventually a second oil cooler to keep things in the comfort zone on a hot day.  You might consider an auxiliary oil/coolant heat exchanger.
>>>>  
>>>> Now that you are a "real" pilot, get out there at 0700 when air temp is below 80 and maybe you can fly long enough to enjoy it.
>>>>  
>>>> Al
>>>>  
>>>>  
>>>> -----Original Message-----
>>>> From: reflector-bounces at tvbf.org [mailto:reflector-bounces at tvbf.org] On Behalf Of Chris Barber
>>>> Sent: Saturday, June 09, 2012 9:50 AM
>>>> To: REFLECTOR
>>>> Subject: REFLECTOR: First flight
>>>> 
>>>> Cleared to take active and hold. Taxied out. Lined up castering nose wheel down center stripe. Cleared to take off. Added power and engine smoothly ran up. Airspeed coming in. 30 kts...50 kts ....60 kts, approximate rotation speed. Lots of runway (9000 ft).....hold it....70 kts....72 kts... Slight pull on the yoke....AIRBORNE!!! Leaped into ground effect. Screw this, pulled back on yoke and I am climbing. Jiggled the yoke a bit to verify control authority. 
>>>> 
>>>> Climbed to about 400 feet and turned right pattern to crosswind. The Dynon altitude and airspeed seem to be working. That's reassuring. Pattern altitude is only 600 feet and I was there already as I turned to downwind. Leveled off and noticed the clouds were lower than reported and appeared on the ground. Also, noticed coolant temps had dropped to 190....but oil temps were flashing at me and had reached 225 (synthetic Royal Purple). Damn. Ok. Fly the airplane, the oil is not at not a critical level. , but let's just finish the pattern and land. I grabbed my phone while on downwind and attempted to record some data but while I can hear the engine the video is  awful....uh, in my defense, I was a bit distracted and way more concerned with flying. I called the tower and informed them I was coming in. I think they were looking out for me since as I turned to base I noticed the fire department staged just off the runways threshold
>>>> 
>>>> I noted I was a bit far out on down wind so I stared easing over to turn base. Wow. I really overshot it as I blew by the runway and had to use full right rudder to get back to the runway. I wish I had had more rudder. In hindsight I think I was not using much aileron as I was cognoscente that I had no idea of stall characteristics so I did not yet wish too strep a turn. I was able to get over the runway and dump some altitude as I got over the numbers and pulled power. Crap, I am fast. I am lined up and right on the numbers but at 95 kts. I come and touchdown and bounced. Pulled power to idles and settled down easily but fast at 90 and rolled out and exited at Delta. The tower was clearing me back to the city hangars as I was exiting the active. I taxi back and noticed the oil temps had decreased but I don't recall how much, just noticed they were lower.
>>>> 
>>>> I got back to my hangar and popped the door and shut her down. The engine went silent without any hissing or gushing. 
>>>> 
>>>> I called my mom. 
>>>> 
>>>> I am mowing informing the world. 
>>>> 
>>>> I did a walk around and did not see anything missing. I am about to pull the cowl and check things out. 
>>>> 
>>>> I did notice I did not develop a slight hand shaking untill after I landed and exited the aircraft. ;-) Hey, how about that, it really is an aircraft now. Ten years to the day following delivery. 
>>>> 
>>>> Thank you for your support. 
>>>> 
>>>> Christopher Barber, JD
>>>> Houston, Ellington Field (EFD)
>>>> Velocity N17010
>>>> Turbo Rotary 13b
>>>> RWS Re-drive and engine computers
>>>> Dynon Skyview
>>>> Mistral intake
>>>> 
>>>> 
>>>> Sent from my iPhone 4
>>>> 
>>>> 
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>>> 
>>> 
>>> 
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>> 
>> 
>> 
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> 
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