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  #41  
Old 05-16-2014, 10:59 PM
crabandy crabandy is offline
 
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DanH, leftover brakeline/fueline material or hardware store stuff for the piccolo tubes I'm hoping is "similar" enough....

Adels for attaching the Piccolo tubes to the push rod tubes, what's handy for attatching the lower Piccolo tubes? Large Adels to the intake tubes?

I'm on kiddo duty tomorrow and need to get my shopping list in order!
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  #42  
Old 05-17-2014, 06:20 AM
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Quote:
Originally Posted by crabandy View Post
DanH, leftover brakeline/fueline material or hardware store stuff for the piccolo tubes I'm hoping is "similar" enough....
Use the exact spec tubes, installed per the spec, if you wish to have reasonably global information. If you don't care about the ability to make reasonable comparison to others who did the same test, do what you want.

The thinwall K&N tube was available on Ebay, etc. Hardware store vinyl tube seemed to work fine for hookups, although yellow tygon is more heat resistant.

Quote:
Adels for attaching the Piccolo tubes to the push rod tubes, what's handy for attatching the lower Piccolo tubes? Large Adels to the intake tubes?
Don't need adels. Safety wire and some tubing standoffs are fine. In my case the uppers were wired to padded fuel injection lines.



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  #43  
Old 05-17-2014, 01:58 PM
crabandy crabandy is offline
 
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Ok, my helper and I got her tore apart and found the exact K&S tubing at Hobby Haven 50 miles away.


Time to take mama to town for dinner, just happens Hobby Haven is just down the street from a lot of restaurants!
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  #44  
Old 05-18-2014, 10:19 PM
crabandy crabandy is offline
 
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OK, slightly embarrassed to show pics of anything of mine next to DanH's but I should get a B- for effort (It started feeling like work and I got in the get-er-done mode).
Piccolo tubes made as specified, mounted close to specs +/- 3/8 inch for various mounting issues.



I forgot to get a photo but I routed the tubes through the heater inlet on the firewall and zip-tied the tubes to a meter stick in the cockpit. Here's my measurements of the homemade manometer all in inches while flying and removing shoulder harness to try to read meter stick correctly:
Static: Upper tubes-11/78 Lower tubes-12 1/2
Idle RPM: Upper tubes-12 Lower tubes-12 1/2
130 IAS: Upper tubes 17 1/2 Lower tubes-15 1/4
160 IAS: Upper tubes 20 Lower tubes-14 1/2

Not sure the 160 IAS lower tube measurement is accurate, I recorded it as such but it doesn't fit the trend. Any feedback on my pressure differentials is greatly appreciated.

Full tanks and me yielded a gross weight of 1505 lbs and C.G. of 81.93 in my RV7. The airport weather system reported 30.17 inHg and 59*F, my aircraft altimeter set to field elevation yielded 30.17 inHg and OAT of 64*F. Winds aloft at 6000 in my vicinity were forecast at 4*C (I forgot to record direction), at 6000 MSL my OAT indicated 46*F. Perhaps my aircraft OAT reads 3-5*F high, it's mounted between the 2 and 3rd access bay under the right wing. For the speed test I used 5700 pressure altitude, my best guess at 6000 density altitude. I leaned to approximately 80-100*F ROP on my leanest cylinder (#4) which peaks at 1450*F. I performed 4 runs, heading 360 followed by a right turn to heading 240 followed by a right turn to 120 in an attempt to stay in the same air-mass. I also did a random run a heading 180, I wasn't sure I consistent results were possible with my piloting skill (or lack of) but here goes:
Hdg 360: 160 IAS/ 175 TAS/ 183 GS/ 359 TK
Hdg 240: 160 IAS/ 175 TAS/ 171 GS/ 240 TK
Hdg 120: 160 IAS/ 176 TAS/ 179 GS/ 120 TK
Hdg 180: 160 IAS/ 175 TAS/ 175 GS/ 178 TK

I hope to have Excel on my computer in the next couple days, if someone else could enter my info in the spreadsheet that would be great. The rough avg speed is 177 knt TAS with an IAS of 160 so calibrated air speed should be close to +1 knt at this airspeed I believe.

For my purposes the primary purpose of adding the ramp/bump was for CHT cooling, here's some screen shots of my EFIS during the above test. All screen shots here were without the ramp/bump under the above described conditions.
This shot is after a 3 minute taxi and engine runup after a cold start, CHT's all around 300.


At level off after takeoff and climb at 130 IAS from 960-6000 MSL.


Screen shot after all full power runs.


Screen shot after landing and 3 minute taxi back to the hangar.


I've re-installed the ramp/bump and hope to get a test flight done in the morning.
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  #45  
Old 05-19-2014, 12:46 AM
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GLPalinkas GLPalinkas is offline
 
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Quote:
Originally Posted by crabandy View Post


Hdg 360: 160 IAS/ 175 TAS/ 183 GS/ 359 TK
Hdg 240: 160 IAS/ 175 TAS/ 171 GS/ 240 TK
Hdg 120: 160 IAS/ 176 TAS/ 179 GS/ 120 TK
Hdg 180: 160 IAS/ 175 TAS/ 175 GS/ 178 TK

I hope to have Excel on my computer in the next couple days, if someone else could enter my info in the spreadsheet that would be great. The rough avg speed is 177 knt TAS with an IAS of 160 so calibrated air speed should be close to +1 knt at this airspeed I believe.

Andy, Here is what I got using the NTPS formula. I used 3 sets of numbers in different configurations.



The average for 4 runs using your numbers is 177.8 ( the same number as a 3 leg 120 degree test)

Hope this helps and keep up the good work.....
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Last edited by GLPalinkas : 05-19-2014 at 06:22 AM. Reason: Deleted some text
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  #46  
Old 05-19-2014, 07:06 AM
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DanH DanH is offline
 
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Quote:
Originally Posted by crabandy View Post
....I routed the tubes through the heater inlet on the firewall and zip-tied the tubes to a meter stick in the cockpit. Here's my measurements of the homemade manometer all in inches while flying and removing shoulder harness to try to read meter stick correctly:
Static: Upper tubes-11/78 Lower tubes-12 1/2
Idle RPM: Upper tubes-12 Lower tubes-12 1/2
130 IAS: Upper tubes 17 1/2 Lower tubes-15 1/4
160 IAS: Upper tubes 20 Lower tubes-14 1/2
Andy, I'm not sure what we're looking at here. Some numbers don't make sense.

Let's back up a moment and check the installation. A manometer measures the difference between two points. Your plumbing should be like this, one leg connected to aircraft static and the other connected alternately to upper or lower cowl pressure:



Here's your test card. Print it and carry it with you. The text assumes an electronic manometer, and also measuring exit temperature, so ignore those bits.

Zero the manometer before engine start (see the instructions which came with the instrument).

Climb to 3500 feet pressure altitude, i.e. altimeter reads 3500 when set to 29.92.

Set AP altitude hold mode if you have it.

Set AP to heading mode so you can steer with a heading bug.

Set your GPS to indicate track, or find an EFIS page which indicates track.

Set power for roughly 100 knots indicated, the first target airspeed. It does not need to be exact; anywhere from 95 to 105 will do. The key item is stability; we want a nice stable airspeed, meaning you need a stable altitude hold and a locked throttle quadrant.

Set mixture for about 100 ROP, best power, for max heat load to the cylinder heads. Trim when speed stabilizes. Again, no particular exact speed is necessary; just a stable speed which approximates the target speed.

When speed is stable, record GPS groundspeed and GPS track (NOTE: track, not heading).

Turn to a new heading (a 120 degree turn works well). When speed stabilizes, again record GPS groundspeed and GPS track.

Turn to a third heading. When speed stabilizes, again record GPS groundspeed and GPS track. Now record upper plenum pressure, lower plenum pressure, all CHT readings, exit temperature, and OAT.

To make the pressure measurements, simply connect the upper tube to the open manometer port and record the reading. Now swap the lower line for the upper line and again record the reading.

Pay attention to where you are going. The first heading will use some distance because you are setting power. The second goes quickly, just the time it takes for speed to stabilize after the turn. The third heading requires time to stabilize plus time to record the temperature and pressure data.

Now repeat the procedure for the next higher speed, ballpark 120 knots. Then repeat for 140 knots and 160 knots. The airspace required for each three-leg set will increase with increasing speeds; don’t hit anything solid.

When you get home plug the three groundspeeds and tracks for each speed point into the attached NTPS spreadsheet. The result is your true speed for that temperature and pressure data set.


Quote:
I leaned to approximately 80-100*F ROP on my leanest cylinder (#4) which peaks at 1450*F.
Excellent. Keep doing that, as it nets maximum heat load.
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  #47  
Old 05-19-2014, 08:10 AM
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MarkW MarkW is offline
 
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Andy,
To follow up on what Dan has said.
Your static numbers should be zero. At no forward speed your pressure would be zero difference between plenum and static.
Moving forward you would have a positive pressure difference between plenum and static.
Looking at your numbers we could take your static numbers and round those to zero by reducing 12.
If we took your 160 kts numbers we could also reduce those by 12 and get 8" upper and 2.5" lower.
They would be zero'd at altitude. And as Dan mentions you need to connect the static port to the ships static system as we all learned from training that the static changes in the cockpit during flight.
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  #48  
Old 05-19-2014, 08:47 AM
crabandy crabandy is offline
 
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Doh, seems I've negatively transferred the fuel tank pressure testing setup to my cowling pressures. My upper piccolos are T'd together and is the clear tubing, the lower piccolos are T'd together and is yellow.


I charted the initial level and figured the difference between the two would be my differential. I knew the static cabin was different, didn't think about hooking it to the static system.
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  #49  
Old 05-19-2014, 09:22 AM
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Might want to just buy a digital manometer. Quite a few different sellers available. Three of us have used this particular model and they were fine:

http://www.ebay.com/itm/Digital-Mano...item1c17cb2054
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  #50  
Old 05-19-2014, 09:25 AM
crabandy crabandy is offline
 
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A little bit warmer today, airport weather reported 60*F and 29.86 inHg. My EFIS was 65*F and 29.88 on the ground. Winds aloft at 6000 were forecast at 210@30 and 15*C, When I started my test at 5000 pressure altitude my EFIS was 60*F when I ended it was 62*F. Density altitude was close to 6000.

My RV7 was at the same 1505 Gross Weight with a C.G. of 81.93, with the bump/ramp installed leaned for 80-100 ROP on my leanest cylinder. Gusty winds and low broken layer today, smoother above the layer but I had a harder time getting everything stabalized. (no autopilot) Here's my 4 runs I believe it actually is faster:
HDG 360: 161.5 IAS/ 177 TAS/ 210 GS/ 002 TK
HDG 240: 161.5 IAS/ 177 TAS/ 147 GS/ 247 TK
HDG 120: 161.5 IAS/ 177 TAS/ 185 GS/ 106 TK
Hdg 030: 161.5 IAS/ 177 TAS/ 215 GS/ 029 TK

Not sure about the validity of my pressures now but here they are measured in inches of water at cabin static pressure. Very similar as the readings without the bump/ramp.
Static (zero point): upper 11 7/8 lower 11 1/4
Idle: upper 12 lower 11 1/4
130 IAS: upper 17 3/4 lower 14
161.5 IAS: upper 20 lower 14 1/2

EFIS screenshot after 2 min taxi and runup. OAT on the ground very similar Average CHT without bump/ramp was 299.75, with the bump/ramp 288.



EFIS screenshot after level off from 130 IAS at 6000 density altitude, about 15*F warmer today. Without the bump/ramp the average CHT was 367.25, with the bump/ramp they were 363.5.


EFIS screenshot after 4 speed runs at 6000 density altitude, again about 15*F warmer today. Without the bump/ramp average CHT was 377.75, with the bump/ramp was 381.75.


EFIS screenshot at shutdown, yesterdays was a low power gliding descent with a 2 min taxi after landing with average CHT's of 297.25. Today I flew level above the broken layer, dove down and flew level to the airport, did a go-around because of winds and a 2 min taxi average CHT was 302.75. I forgot to note the OAT at shutdown, but when I got in the car 30 minutes later it was 75*F.


Whew, lots of typing now I gotta run!
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Last edited by crabandy : 05-19-2014 at 11:11 AM. Reason: fixed photo links
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