Constant gas flow, has anyone tried this ?
03-09-2009, 10:06 PM
#1
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Sep 2002
Location: Mexico City, MEXICO
Posts: 441
Likes: 0
Received 0 Likes
on
0 Posts
Constant gas flow, has anyone tried this ?
Hi all
I wonder if this gas tank set up has ever been used by anyone succesfully and if it really works on gas engines?
Reason why I am asking this (or perhaps I am beeing too paranoic?), check out this:
[link=http://video.google.com/videoplay?docid=41325231501487529]gas flow video[/link]
I wonder if this gas tank set up has ever been used by anyone succesfully and if it really works on gas engines?
Reason why I am asking this (or perhaps I am beeing too paranoic?), check out this:
[link=http://video.google.com/videoplay?docid=41325231501487529]gas flow video[/link]
03-09-2009, 10:15 PM
#3
My Feedback: (19)
RE: Constan gas flow, has anyone tried this ?
Thats just a large tank feeding into a smaller or "header" tank. You would plug what I would refer to as the filler line on the smaller tank for flight. Not really necessary for gassers because the pump in the carb assures a constant fuel supply to the engine in most any attitude.
You see this basic setup used on helicopters (less the fill line on the small tank) and on some glo power airplanes. Again used to assure a constant, bubble free fuel supply to the engine. Glo engines die when bubbles go through the carb where the spark ignition on gassers keeps things going with maybe just a bit of a hic-up if the line goes dry for a bit.
You see this basic setup used on helicopters (less the fill line on the small tank) and on some glo power airplanes. Again used to assure a constant, bubble free fuel supply to the engine. Glo engines die when bubbles go through the carb where the spark ignition on gassers keeps things going with maybe just a bit of a hic-up if the line goes dry for a bit.
03-09-2009, 10:20 PM
#4
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Sep 2002
Location: Mexico City, MEXICO
Posts: 441
Likes: 0
Received 0 Likes
on
0 Posts
RE: Constan gas flow, has anyone tried this ?
mm... makes sense, also the more complex the easier to fail.
I had a have had couple of dead sticks in the past due to a seemingly unknown reason, I wonder if what the video shows could ever happen to me.hh
Although this ariplane lands safely, its clunk will eventually be outside the flotation line.
I had a have had couple of dead sticks in the past due to a seemingly unknown reason, I wonder if what the video shows could ever happen to me.hh
Although this ariplane lands safely, its clunk will eventually be outside the flotation line.
03-09-2009, 10:51 PM
#5
RE: Constan gas flow, has anyone tried this ?
Interesting video. I always thought the fuel would stay at the back of the tank when the nose of the plane was pointed down. I guess not. I learned something.
03-09-2009, 11:29 PM
#6
My Feedback: (1)
Join Date: Apr 2003
Location: Left Coast ,
CA
Posts: 4,890
Likes: 0
Received 0 Likes
on
0 Posts
RE: Constant gas flow, has anyone tried this ?
I guess the argument about which way the fuel goes in your tank on a down line has been answered. Where was that video when the debate was hot and heavy.
03-10-2009, 08:38 AM
#8
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Sep 2002
Location: Mexico City, MEXICO
Posts: 441
Likes: 0
Received 0 Likes
on
0 Posts
RE: Constant gas flow, has anyone tried this ?
That´s the point around the gas tank set up described in the schematic above.
I rarely do long down lines; however I do a lot of 3D.
The only other time where I have had thousands of questions in my mind aboout what did really happen to my airplane is right after experiencing a dead stick.
I wonder if this could explain some of them.
Anyway since the gas tank set up is rarely used I guess we don´t have a valid statistic data to confirm that this could bullet proof agaist dead sticks due to fuel starvation.
I rarely do long down lines; however I do a lot of 3D.
The only other time where I have had thousands of questions in my mind aboout what did really happen to my airplane is right after experiencing a dead stick.
I wonder if this could explain some of them.
Anyway since the gas tank set up is rarely used I guess we don´t have a valid statistic data to confirm that this could bullet proof agaist dead sticks due to fuel starvation.
03-10-2009, 09:10 AM
#9
My Feedback: (19)
RE: Constant gas flow, has anyone tried this ?
Most common cause of dead sticks in gassers is probably having the idle speed set too low. In glo engines, its probably fuel flow interruption. I have solved unexplained dead sticks on glo engines by using a small header tank mounted in the cowl area near the engine. Just never seemed necessary with gas though.
Gassers usually have long fuel lines. Just the fuel in the line can sustain a gasser for a very long time at low throttle or idle during downlines. The pump pulls fuel as soon as the clunk is back in fuel and the spark ignition assures the fire never goes out in the cylinder. All in all, things just work out to prevent problems. Just another reason people like gassers.
Gassers usually have long fuel lines. Just the fuel in the line can sustain a gasser for a very long time at low throttle or idle during downlines. The pump pulls fuel as soon as the clunk is back in fuel and the spark ignition assures the fire never goes out in the cylinder. All in all, things just work out to prevent problems. Just another reason people like gassers.
03-10-2009, 10:19 AM
#10
Senior Member
Thread Starter
My Feedback: (7)
Join Date: Sep 2002
Location: Mexico City, MEXICO
Posts: 441
Likes: 0
Received 0 Likes
on
0 Posts
RE: Constant gas flow, has anyone tried this ?
ORIGINAL: Truckracer
Most common cause of dead sticks in gassers is probably having the idle speed set too low. In glo engines, its probably fuel flow interruption. I have solved unexplained dead sticks on glo engines by using a small header tank mounted in the cowl area near the engine. Just never seemed necessary with gas though.
Gassers usually have long fuel lines. Just the fuel in the line can sustain a gasser for a very long time at low throttle or idle during downlines. The pump pulls fuel as soon as the clunk is back in fuel and the spark ignition assures the fire never goes out in the cylinder. All in all, things just work out to prevent problems. Just another reason people like gassers.
Most common cause of dead sticks in gassers is probably having the idle speed set too low. In glo engines, its probably fuel flow interruption. I have solved unexplained dead sticks on glo engines by using a small header tank mounted in the cowl area near the engine. Just never seemed necessary with gas though.
Gassers usually have long fuel lines. Just the fuel in the line can sustain a gasser for a very long time at low throttle or idle during downlines. The pump pulls fuel as soon as the clunk is back in fuel and the spark ignition assures the fire never goes out in the cylinder. All in all, things just work out to prevent problems. Just another reason people like gassers.
After reading your reply, I feel more comfortable now.
03-10-2009, 10:55 AM
#12
Senior Member
My Feedback: (1)
RE: Constant gas flow, has anyone tried this ?
The header tank concept is used quite a lot for gas engine installations. Engine stops from fuel starvation just don't happen unless the tanks are dry. However the planes aren't used for aerobatics either.
03-10-2009, 12:47 PM
#13
RE: Constant gas flow, has anyone tried this ?
The fuel in the header tank behaves just like the fuel in the main tank, just as shown in the video.
Note that the fuel is always sucked from the central point of the header tank.
When bubbles arrive from the main tank, they go to the top of the header tank, regardless the position of the airplane, and stay there.
As long as the growing accumulation of air does not reach that central point, the engine receives fuel.
Later, when refueling, that big bubble of accumulated air is pumped back to the main tank, and the next flight starts with an airless header tank.
Note that the fuel is always sucked from the central point of the header tank.
When bubbles arrive from the main tank, they go to the top of the header tank, regardless the position of the airplane, and stay there.
As long as the growing accumulation of air does not reach that central point, the engine receives fuel.
Later, when refueling, that big bubble of accumulated air is pumped back to the main tank, and the next flight starts with an airless header tank.
03-10-2009, 01:07 PM
#14
My Feedback: (35)
Join Date: Jul 2003
Location: Bowling Green,
KY
Posts: 2,497
Likes: 0
Received 0 Likes
on
0 Posts
RE: Constant gas flow, has anyone tried this ?
Same system used in turbines. Main tanks feed a hopper tank to keep air out of the lines. A must for jets. The hopper tank is tilted at a angle to keep the air on top. Dennis
03-10-2009, 01:31 PM
#15
Senior Member
Join Date: Jul 2005
Location: Pearl City,
HI
Posts: 603
Likes: 0
Received 0 Likes
on
0 Posts
RE: Constant gas flow, has anyone tried this ?
ORIGINAL: lnewqban
The fuel in the header tank behaves just like the fuel in the main tank, just as shown in the video.
Note that the fuel is always sucked from the central point of the header tank.
When bubbles arrive from the main tank, they go to the top of the header tank, regardless the position of the airplane, and stay there.
As long as the growing accumulation of air does not reach that central point, the engine receives fuel.
Later, when refueling, that big bubble of accumulated air is pumped back to the main tank, and the next flight starts with an airless header tank.
The fuel in the header tank behaves just like the fuel in the main tank, just as shown in the video.
Note that the fuel is always sucked from the central point of the header tank.
When bubbles arrive from the main tank, they go to the top of the header tank, regardless the position of the airplane, and stay there.
As long as the growing accumulation of air does not reach that central point, the engine receives fuel.
Later, when refueling, that big bubble of accumulated air is pumped back to the main tank, and the next flight starts with an airless header tank.
