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  #21  
Old 09-02-2019, 09:12 AM
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DanH DanH is offline
 
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David, have you tried some insulation on the metallic parts? Maybe some fiberfrax covered in aluminum foil tape?

Abnormal behavior initially after climb, vs generally normal after some time period in cruise. Kinda suggests something cooled down a bit. The photos don't show proximity to exhaust pipes.
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  #22  
Old 09-02-2019, 09:29 AM
BillL BillL is offline
 
Join Date: Sep 2007
Location: Central IL
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Default Great Job Team!!

It is great to see collaboration of a common design emerging for builders to use and remove some of the experimental risk of a build while adding durability and reliability to our birds. Congrats to all who contributed!!!

Quote:
Originally Posted by DanH View Post
Prediction: Near the divider will be much cooler than any lower cowl location when in flight, and not worse when parked hot.
Having lots of temperature data recorded, I will have to agree with Dan. Although the heads are higher it seems the case, barrels are the dominant driver of the under cowl, under plenum temperatures. I don't have the southern absolute temps but the shut downs seem to follow case and oil temps less than the heads, in my data.

Quote:
Originally Posted by TS Flightlines View Post
.. . . So we set out to test this idea. 2 airshow seasons with members of an well known show team with good results in 3 variations.
WE have a bunch of these flying around the world with no issues. The one part that did need some help was making a securing bracket that would work for that application. Dan Horton did a great job of this. Again, not for everyone, but better than it was. . . .

Tom
Tom, we have heat/temps, internal flow and fluids, fundamental structural of the mounts, and lastly vibration of the cube. Vibration of the small displacement high kind would be the one of concern since it is rigidly attached to the case. It is a fundamental question for anything that gets bolted directly to any engine.

So - was one of the configurations you tested in the field this mount structure? If so that would eliminate that as a potential issue.

There have been many rigidly attached to the lower structure and they seem to be working quite well. The only thing we could do better is measure the vibration of the cube and it's mounts.
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  #23  
Old 09-02-2019, 09:42 AM
kaweeka kaweeka is offline
 
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Dan,
I thought about the temperature aspect for the same reason you did while EI was doing their testing. I'll order some insulating material from ACS and report what happens. I really appreciate the brain trust!
David
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  #24  
Old 09-02-2019, 10:43 AM
TS Flightlines TS Flightlines is offline
 
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Bill---this mounting bracket was not tested, as it wasnt even conceived then.
The fitting concept was tested, with excellent results.

Tom
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  #25  
Old 09-02-2019, 09:31 PM
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RVbySDI RVbySDI is offline
 
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Quote:
Originally Posted by scsmith View Post
I violated one of the install guidelines and mounted it in the cockpit, between the boost pump and the mechanical pump. But it has long straight runs of tubing on both the inlet and outlet sides, with a smooth large radius bend in the tube far upstream. No elbows. I find that fuel flow indication when the boost pump is on is erroneous. Common finding, but the lesser of evils in my mind at the time.

I like your install, except for the elbow immediately upon exit of the cube. This turn in the flow so close to the cube may cause an error in the fuel flow calibration. As long as it is consistent, you can calibrate it out by tweaking the K value. If the influence varies at different fuel flows, it is going to be an issue.

Have others installed this way with an elbow right at the outlet?
just posting as an additional data point. I also mounted my red cube on the cockpit side of the firewall. In fact, due to the ECI constant flow fuel injection I have on the IO340, I have two red cubes inside the cockpit. The outflow cube, going to the engine is mounted as Steve mentioned, after the boost pump and before the mechanical pump. The return fuel line has a second cube on the cockpit side of the firewall as the fuel returns to the fuel selector.

Steve, I do have an elbow after the cube as the line exits the cube and goes through the firewall. My fuel flow readings have been exceptionally accurate. I have 9 years and about 650 hours with dead on accurate readings that are within .01-.02 gph when calculating my fuel burn at fill up. The potential problems with heat and vibration in the engine compartment were the underlying reasons I chose this location. It has worked very well for my airplane.
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  #26  
Old 09-10-2019, 01:08 PM
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RVbySDI RVbySDI is offline
 
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Quote:
Originally Posted by gfb View Post
This is a great improvement from the last one, thanks for sticking with it, we all benefit from your efforts.

Is Tom or someone making the brackets? Or might you post some dimensions? I have the afp spider bracket which doesn’t look like yours but is likely an easy replacement. Who makes your spider bracket?
I would second the request for some dimensional information on the final bracket.
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