VansAirForceForums  
Home > VansAirForceForums

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

- Today's Posts | Insert Pics

  #1  
Old 07-14-2017, 07:42 PM
LUKLA LUKLA is offline
 
Join Date: Apr 2016
Location: Phoenix,AZ
Posts: 53
Default Fuel tank Air vent.

Just curious.
Is any one has done your air vent differently than just making #30 hole in the fuel cap on RV12 gas tank.
I have heard there is new way ppl are doing but haven't seen any picture or schematic or instruction.
input will be appreciate as always.

LUKLA
Reply With Quote
  #2  
Old 07-14-2017, 08:10 PM
Slane Slane is offline
 
Join Date: May 2008
Location: Hillsboro, OR
Posts: 150
Default Fuel tank air vent

See section 37: http://www.vansaircraft.com/pdf/revi...Section_37.pdf
__________________
Scott Lane
Hillsboro, OR
RV12 Completed & Flying 2013
#120043 N728SL
VAF paid 2017
Reply With Quote
  #3  
Old 07-14-2017, 08:30 PM
2johns 2johns is offline
 
Join Date: Apr 2008
Location: Great Falls, Montana
Posts: 76
Default

I think it is a very good idea to change the fuel vent location as Van's has suggested in 37-01 Rev 5 due the possibility of the hole in the cap being plugged or a new owner being unaware of the hole in the cap, losing the cap, replacing it with a new one without drilling the the vent hole. A possible cause of a disaster. I made the revision moving the vent to the top of the tank. Only problem was that I have an automatic shut off and when it shuts off, a small amount of gasoline would spew out the new vent onto the floor. Why, I do not know. I then moved the vent an inch or so below the top of filler neck and plugged the fitting on the top of the tank using the same vent outlet location on the bottom of the fuselage to solve this problem.
Reply With Quote
  #4  
Old 07-15-2017, 10:28 AM
scottmillhouse scottmillhouse is offline
 
Join Date: Apr 2007
Location: Madison, AL
Posts: 134
Default

I recommend having both vents, the new tank and the cap. I initially built mine without the cap vent and was having variable fuel pressure when the tank was filled. Put a vent hole per instructions in cap and no problem the last 100 hours.
__________________
Scott- 2017 dues paid
RV-12 #120515, 319RV 175 hours.
1st flight 12/08/15, flew SNF, Oshkosh, Triple Tree & SERFI in year 1!
RV-9A, 536 hours, sold
Reply With Quote
  #5  
Old 07-15-2017, 11:51 AM
Phantom30's Avatar
Phantom30 Phantom30 is offline
 
Join Date: Jul 2009
Location: Coeur d'Alene, ID/Casa Grande, AZ
Posts: 543
Default

Quote:
Originally Posted by scottmillhouse View Post
I recommend having both vents, the new tank and the cap. I initially built mine without the cap vent and was having variable fuel pressure when the tank was filled. Put a vent hole per instructions in cap and no problem the last 100 hours.
Very interesting....me thinks I'll try that as I've seen changing (lowering) fuel pressure as fuel is consumed (and I know my vent works as fuel runs out if I overfill tank)...

Scott...where would find instructions on how to drill vent hole in cap?
__________________
Ric Dickison
307 (CAB) Phantom
Search and Destroy (Can
Tho RVN)
Distinguished Flying Cross Society Member
CH-47 & UH-1H "Driver"
Rotax 9 Series Service IRMT

RV-12 Kit#729 "N312RD" is now a full functioning fun machine!! Thanks Van for fulfilling my dream😎
2017 Dues Paid
Reply With Quote
  #6  
Old 07-15-2017, 03:45 PM
Piper J3's Avatar
Piper J3 Piper J3 is offline
 
Join Date: Nov 2014
Location: Hinckley, Ohio
Posts: 663
Default

Actually I subscribe to the vented cap all by itself. I use 93E10 auto fuel exclusively and donít want a lot of air exchange in the tank. Alcohol is very hydroscopic and will absorb moisture in the air. Also, octane rating for auto fuel will diminish if not stored in a sealed container.

So I run a cap with the small vent hole and have had zero problems in 258 hours. When I did the fuel tank SB I elected to not install the new vent system. Fuel pressure and fuel flow are rock steady regardless of fuel quantity.
__________________
-
Jim Stricker
Hinckley, Ohio
PPL - 1970
80 hrs Flying Aeronca Chief 11AC
1130 hrs Flying 46 Piper J-3 Cub
RV-12 E-LSA #120058 AWC 7/12 Bought Flying 10/2015 with 48TT - Hobbs now 288
Reply With Quote
  #7  
Old 07-15-2017, 04:43 PM
LUKLA LUKLA is offline
 
Join Date: Apr 2016
Location: Phoenix,AZ
Posts: 53
Default

Quote:
Originally Posted by Piper J3 View Post
Actually I subscribe to the vented cap all by itself. I use 93E10 auto fuel exclusively and donít want a lot of air exchange in the tank. Alcohol is very hydroscopic and will absorb moisture in the air. Also, octane rating for auto fuel will diminish if not stored in a sealed container.

So I run a cap with the small vent hole and have had zero problems in 258 hours. When I did the fuel tank SB I elected to not install the new vent system. Fuel pressure and fuel flow are rock steady regardless of fuel quantity.
So verdict is Just make # 30 hole in fuel cap and it will do perfect !!!

Thanks a lot Folks.
Lukla
Reply With Quote
  #8  
Old 07-15-2017, 05:04 PM
DHeal DHeal is offline
 
Join Date: Sep 2006
Location: Windsor, California
Posts: 599
Default

I have the Van's early plan's holes in the fuel cap. It seems to be working fine for me over 500+ hours. Just be sure that as part of your pre-flight that you remove the cap and blow air (breath) through the holes to ensure that they are free and clear of debris, bugs, etc. Also, during outside exposure to rain, I tape a piece of plastic sheeting over the cap that is positioned to keep rain out of the cap area yet would blow away in the prop wash if I were to forget to remove it before flight.
__________________
David Heal - Windsor, CA (near Santa Rosa)
EAA #23982 - EAA Technical Counselor and Flight Advisor; CFI - A&I
RV-12 E-LSA #120496 (SV w/ AP and ADS-B) - N124DH flying since March 2014 - 540+ hours (as of Sept 2017)!
VAF donation through June 2018.
Reply With Quote
  #9  
Old 07-15-2017, 06:35 PM
RFSchaller RFSchaller is offline
 
Join Date: Oct 2010
Location: Phoenix, AZ
Posts: 2,051
Default

I do the same as David. 600 hours and 5 years later the vented cap still works great.
Reply With Quote
  #10  
Old 07-15-2017, 06:42 PM
DBRuth DBRuth is offline
 
Join Date: Nov 2013
Location: Cumming,GA
Posts: 72
Default Double vent

I also have the new style vent system and the vented cap. I drilled mine to the tap size for 4-40 and then tapped both the cap and the lower plate 4-40, just in case I didn't like the results. I had a couple of flights when I smelled fuel on climb out before I vented the cap, and none since vented. Needless to say I have not had to block off the cap vent. 117 hours total, approximately 100 hours with both vents,no problems.
__________________
N412DR
Kit 120797
First flight 8/21/15 what an awesome aircraft!
HOBBS @114.5
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 07:20 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.