VansAirForceForums  
Home > VansAirForceForums

- POSTING RULES
- Donate yearly (please).
- Advertise in here!

- Today's Posts | Insert Pics


Go Back   VAF Forums > Model Specific > RV-9/9A
Register FAQ Members List Calendar Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
  #11  
Old 06-14-2017, 10:44 AM
PilotjohnS PilotjohnS is offline
 
Join Date: Jan 2016
Location: Los Angeles
Posts: 346
Default Thanks all

Ok thanks everyone for the quick and thoughtful repsonses.

So I have decided no mods on the fuel senders, I will stick with what is tried and proven.

You are all right, what was I thinking?
__________________
Thank you
John S

WARNING! Information presented in this post is my opinion. All users of info have sole responsibility for determining accuracy or suitability for thier use.

Extra dues paid 2017, worth every penny

RV9A- Status: tail feathers done less tips
Wings 50%
www.pilotjohnsrv9.blogspot.com
Reply With Quote
  #12  
Old 06-14-2017, 10:50 AM
Mel's Avatar
Mel Mel is online now
 
Join Date: Mar 2005
Location: Dallas area
Posts: 9,666
Default Your thinking was fine!

There's absolutely nothing wrong with thinking outside the box. You did the right thing by researching before you jumped in.
__________________
Mel Asberry..DAR since last century
A&P/EAA Tech Counselor/Flight Advisor
Specializing in Amateur-Built and Light-Sport Aircraft
<n168tx(at)flytx.net>
North Texas (8TA5)
RV-6 Flying since 1993
175hp O-320
3-Blade Catto (since 2003)
FRIEND of the RV-1
Eagle's Nest Mentor
Reply With Quote
  #13  
Old 06-14-2017, 01:15 PM
Snowflake's Avatar
Snowflake Snowflake is offline
 
Join Date: Oct 2009
Location: Victoria, BC, Canada
Posts: 2,969
Default

I installed a fuel flow meter (red cube) in my aircraft, and now that i've used it I regret not installing two of them... One on each tank. I use an MGL gauge to read left and right levels (from the resisitive senders) and the fuel flow (from the red cube). Flow is used to show a total used number (which is combined for both tanks). The total used matches what I put in at the pump to within 1L out of a full tank. I only look at the levels as a rough guide, even after repeated calibrations and tweaking of set points I haven't managed to get them to read accurately (like, 3-4L off at some points).

Two flow meters would be mounted outside the tank, saving more volume inside for fuel. Less things to fail inside the tank, less holes through to the tank that might leak later, etc. etc.
__________________
Rob Prior
1996 RV-6 "Tweety" C-FRBP (formerly N196RV)
Reply With Quote
  #14  
Old 06-14-2017, 01:43 PM
JonJay's Avatar
JonJay JonJay is offline
 
Join Date: Jan 2007
Location: Battleground
Posts: 3,642
Default

Quote:
Originally Posted by Snowflake View Post
I installed a fuel flow meter (red cube) in my aircraft, and now that i've used it I regret not installing two of them... One on each tank. I use an MGL gauge to read left and right levels (from the resisitive senders) and the fuel flow (from the red cube). Flow is used to show a total used number (which is combined for both tanks). The total used matches what I put in at the pump to within 1L out of a full tank. I only look at the levels as a rough guide, even after repeated calibrations and tweaking of set points I haven't managed to get them to read accurately (like, 3-4L off at some points).

Two flow meters would be mounted outside the tank, saving more volume inside for fuel. Less things to fail inside the tank, less holes through to the tank that might leak later, etc. etc.
Works great until it doesn't. i have had a fuel flow sender fail slowly. I discovered it while I was flying a long leg. My fuel level senders are amazingly accurate once they get off the top of the tank. I noticed the issue through my normal scan, checking my level against the totalizer. I have four fuel status relative checks - fuel totalizer - fuel level - clock and brain - and to a much lesser degree, fuel flow.
I wouldn't want to give up any of them.
__________________
Smart People do Stupid things all the time. I know, I've seen me do'em.

RV6 - Builder/Flying
Bucker Jungmann
Fiat G.46 -(restoration in progress, if I have enough life left in me)
RV1 - Proud Pilot.
Reply With Quote
  #15  
Old 06-14-2017, 02:18 PM
Bevan Bevan is offline
 
Join Date: Sep 2007
Location: BC
Posts: 1,436
Default

Fuel level senders (one per tank) and a separate fuel totalizer system when used together are unbeatable in my opinion. Granted, the fuel level senders don't sense the top of the tank but that's not all that useful anyway. Sensing the bottom levels and comparing that to what the totalizer is telling you is useful.

Bevan
__________________
RV7A Flying!
O-360-A1F6 (parallel valve) 180HP
Dual P-mags
Precision F.I. with AP purge valve
Vinyl Wrapped Exterior
Grand Rapids EFIS
Located in western Canada
Reply With Quote
  #16  
Old 06-14-2017, 02:46 PM
larrynew's Avatar
larrynew larrynew is offline
 
Join Date: Oct 2007
Location: In New Braunfels, ist das Leben schön!
Posts: 711
Default

I am extremely pleased with the accuracy of the stock Van's resistive system combined with Skyview's fuel flow totalizer. The red cube has been amazingly accurate and the resistive fuel measurement is a good gross confirmation that I don't have a leak in addition to also being accurate compared to the totalizer and refuel totals after they come off the top. I have more confidence in the fuel measurements in my RV than I did in the military or airlines.
__________________
Larry New
RV-7A - Flying 500+ hrs
VAF Paid - Annual Autodraft
Reply With Quote
  #17  
Old 06-14-2017, 04:27 PM
airguy's Avatar
airguy airguy is offline
 
Join Date: Oct 2006
Location: Garden City, Tx
Posts: 3,872
Default

Quote:
Originally Posted by larrynew View Post
I am extremely pleased with the accuracy of the stock Van's resistive system combined with Skyview's fuel flow totalizer. The red cube has been amazingly accurate and the resistive fuel measurement is a good gross confirmation that I don't have a leak in addition to also being accurate compared to the totalizer and refuel totals after they come off the top. I have more confidence in the fuel measurements in my RV than I did in the military or airlines.
Same here. I started with capacitive senders in the tanks and had nothing but trouble with them, ended up going back to the standard resistive floats. My Red Cube totalizer is my primary fuel instrument though, with the resistive floats as a backup to guard against a leak somewhere before the totalizer. The resistive floats won't read the top 4 gallons in each tank and I really don't care anymore. I set the fuel computer to 36 gallons each time I top off, and it matches gallons pumped extremely well.
__________________
Greg Niehues - VAF 2017 dues paid
Garden City, TX
N16GN flying! http://websites.expercraft.com/airguy/
Built an off-plan 9A with too much fuel and too much HP. Should drop dead any minute now.
Reply With Quote
  #18  
Old 06-14-2017, 10:04 PM
rapid_ascent rapid_ascent is offline
 
Join Date: Mar 2008
Location: Dublin, CA
Posts: 822
Default

Oh I was thinking one set was for inverted flight.
__________________
Ray Tonks
2016 Donation Paid
RV-7 Fuselage in progress
* Mid Fuselage Complete
* Aft Fuselage Complete
RV-7 SB Wings
* Both Wings fully skinned
* Fuel Tanks Complete - No leaks finally
* Ailerons Complete
* Flaps Complete
RV-7 Empennage - Complete (a little fiberglass work left)
Vans Training Kit # 2 - Complete
Shop Setup - In Progress (Gathering Tools, Never Complete)
RV-7 Preview Plans
Vans Training Kit #1 - Complete
EAA Sheet Metal Class - Complete
Reply With Quote
  #19  
Old 06-15-2017, 12:19 AM
Evolution10 Evolution10 is offline
 
Join Date: Jun 2014
Location: oregon
Posts: 91
Default

I have duel senders in each tank - I used the senders provided by CIES (think Cirrus/Beechcraft among others). Works great and is incredibly accurate. I get readings all the way to empty. Never have I experienced any deviation in reading versus actual! Highly recommended.
Reply With Quote
  #20  
Old 06-15-2017, 08:58 AM
Larry DeCamp's Avatar
Larry DeCamp Larry DeCamp is online now
 
Join Date: Apr 2010
Location: Clinton, Indiana
Posts: 530
Default Another approach

Although resistive float senders are endorsed above, I read many negative comments in the archives about accuracy and reliability. In fact as installed, either the sender or the gauge didn't work. Yes, that could been resolved . But, I stripped them out and replaced them with simple optical sensors ( referenced here in archives) that trigger flashing lights with " yes/no" simplicity. I never leave the ground without measuring fuel levels and update the totalizer. The Red cube has been very accurate, two might be an enhancement but which one would you believe ? Then you look at your watch and flow rate for truth anyway. Bottom line, the low level sensor lights tell you accurately how much time is left in that tank or " don't land " on that tank if you have set the sensor low. I have set mine at about 2 1/2 gallon.
__________________
Larry DeCamp
RV-3B flying
RV-4 fastback project in the shop
Clinton, IN
Reply With Quote
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump


All times are GMT -6. The time now is 07:24 AM.


The VAFForums come to you courtesy Delta Romeo, LLC. By viewing and participating in them you agree to build your plane using standardized methods and practices and to fly it safely and in accordance with the laws governing the country you are located in.