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  #21  
Old 02-03-2019, 01:02 PM
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Piper J3 Piper J3 is offline
 
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Quote:
Originally Posted by pilotyoung View Post
Jim,

Is there any reason a dowel rod could not be used to measure and mark the fuel quantity in the tank?
Round dowel rod will work fine. Needs to sneak around the fuel return line that points up at the base of the filler neck.
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 459

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H
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  #22  
Old 02-03-2019, 02:17 PM
Dave12 Dave12 is offline
 
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You should be careful when using the dowel rod. Make sure it misses the fuel return line that is at the bottom of the filler neck.
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  #23  
Old 02-04-2019, 10:22 AM
NinerBikes NinerBikes is offline
 
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Location: Granada Hills
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Quote:
Originally Posted by rvbuilder2002 View Post
Your prop isn't pitched for cruising.... it is over pitched.
This will have a negative effect on oil temp in hot weather and can cause other problems (besides giving up climb performance that you don't have to).

I have no comment on the RPM difference. I have never seen any indication of a change with fuel type. My guess is that you are seeing differences with different weather conditions (density altitude).
What "other problems" are you suggesting?

This is not my plane, the owner set the plane up with the prop pitch he has because he mostly flies solo. That puts his gross weight with a full tank at about 1060 lbs on a full tank, if that makes any difference.

He usually cruises at 21-22" of manifold pressure and 105-110kts IAS 2500 - 7500 ft ASL, a little faster and in the yellow, if the air is glassy and smooth.
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  #24  
Old 02-04-2019, 11:53 AM
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Piper J3 Piper J3 is offline
 
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Quote:
Originally Posted by NinerBikes View Post
What "other problems" are you suggesting?
As Scott said, the prop is over-pitched. Full throttle in level flight should easily red line at 5500+ RPM. When pitched correctly ~ 115 kts at 5400 PRM is the norm with throttle pulled about about 1".

Over-pitch can cause serious detriment to the engine - detonation, high heat/wear, not to mention < TBO.

Search forum for setting prop pitch...
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 459

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H
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  #25  
Old 02-04-2019, 02:05 PM
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DaleB DaleB is offline
 
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And slower cruise speed, and higher fuel consumption...
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Omaha, NE
RV-12 # 222 N980KM "Screamin' Canary" (bought flying)
Fisher Celebrity (under construction)
Previous RV-7 project (sold)
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  #26  
Old 02-05-2019, 03:38 PM
NinerBikes NinerBikes is offline
 
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We will be flying to Copper State Fly In, this weekend. I should have a GoPro Hero 7 Black set up to video what the gauges are showing, so that I can more closely know and speak factually about observations on fuel usage, rpm and IAS readings.

Bob seems to think when he set the props that he would see 5500 rpm at level flight, but doesn't remember the IAS obtained in level flight, or the elevation of flight ASL. About 130 hours now on the Hobbs. He does remember a longer trip from So CA to Oregon and back, and average fuel consumption worked out to 4.9 gallons per hour for the whole trip. No idea how fast he was flying, then.
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  #27  
Old 02-05-2019, 09:23 PM
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Piper J3 Piper J3 is offline
 
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I guess I don’t understand why so much concern about exact fuel gage readings, or for that matter, differences in fuel burn rates. The gages we have… Moeller, digital EMS, and old sight gage on the side of the tank – all are very accurate at low fuel levels where it counts most. So if you’re burning 4.5, or 5, or 5.5 GPH you still need to plan and maintain sufficient fuel reserve.

I count my blessings that our fuel gages are far more accurate than wing root float gages in and old Cessna or electric analog gages in a Piper.
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 459

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H
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  #28  
Old 02-05-2019, 10:27 PM
RFSchaller RFSchaller is offline
 
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Location: Phoenix, AZ
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Jim,

My experience is that the sensor float travel does not span the entire height of the tank, so if you bend the float wire to bottom out at the tank bottom I agree with your statement of accuracy at the low end, but if a builder does not do that the indicated level will not be accurate at low level. My float reaches the upper limit of travel at 17 gallons, but is very accurate below 6 gallons. I usually have to fly about an hour on a full tank before the indicated level drops to 16 gallons.

Rich
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  #29  
Old 02-05-2019, 11:14 PM
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DaleB DaleB is offline
 
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My resistive float gauge reads 14 gallons until the level dips below that. It's accurate down to very low levels. The Moeller is useful while filling the tank and double-checking during preflight. I can't see it while flying. The D180 generally knows how much I have left, but it's a little pessimistic -- which I like.

What is the old saying? A man with two watches is never sure what time it is, right? I have three fuel gauges. But if I'm worried about whether I have X gallons or X.5 gallons, I've done something really wrong.
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Omaha, NE
RV-12 # 222 N980KM "Screamin' Canary" (bought flying)
Fisher Celebrity (under construction)
Previous RV-7 project (sold)
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  #30  
Old 02-06-2019, 04:35 AM
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Piper J3 Piper J3 is offline
 
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Quote:
Originally Posted by DaleB View Post
The Moeller is useful while filling the tank and double-checking during preflight. I can't see it while flying.
Dale

Why can't you see the Moeller gage in flight? A glance over your right shoulder should be all that's necessary.
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Jim Stricker
Hinckley, Ohio (1OA2)
EAA #499867
PPL/ASEL 1970 - Sport Pilot since 2007
80 hrs Flying Aeronca Chief 11AC N86203
1130 hrs Flying 46 Piper J-3 Cub N6841H
RV-12 E-LSA #120058 AWC July 2012 N633CM
RV-12 Bought Flying Oct 2015 with 48TT - Hobbs now 459

LSRM-A Certificate 2016
Special Thanks... EJ Trucks - Crew Chief A-4 Skyhawk
MJ Stricker (Father & CFI) - 1st Lt. Captain B-17H
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