The clunk on any type of line will not function reliably if it goes to the front of the tank. The flameout situation is a mixture or mixture /glow plug situation.
I have tried with no success more than once to induce fuel starvation to kill motors that had suffered throttle problems and would be at anything from 1/4 to 1/2 throttle. They have ranged from a SIG Seniorita to a H-9 Sukhoi with a ZDZ 80.
The seniorita sould be flown until it was barely visible and put into a vertical dive that lasted for close to 15 seconds the engine never missed a beat. The Sukhoi displayed the same situation so I flew it around until it went dry and dead sticked it. It had my prop on it so that was my best choice.
The seniorita flew on for about 35 minutes until I drove it onto the runway and broke the prop. It was not my prop.
Any way the point is that empirical findings compiled from 36 years of RC flying suggest that the clunk staying to the rear of the tank supplies fuel until the tank runs dry regardless of flight position, including waterfalls transitioning to a spin to a crash where the engine never missed[8D] a beat.
ORIGINAL: opjose
ORIGINAL: RCKen
ORIGINAL: opjose
The problem with the fuel stiffner is that when you have approximately 1/3 of a tank left or less, and you go nose down, the engine can become fuel starved.
This still doesn't happen. Remember, you are dealing with inertia here. Even with only a small amount of fuel in the tank, if you put the plane in a nose down attitude the fuel will STILL remain in the back of the tank. It's nothing but pure physics. The inertia of the fuel and plane keeps the fuel in the back of the tank. The only time fuel will flow to the front of the tank when the plane is nose down is when there is no forward motion on the plane. I'm sorry to say this, but there is NO circumstances where the clunk should ever be in the front of the tank. As Missleman said, if the clunk were somehow to go forward the fuel line would be pinched anyway and not pickup any fuel.
Ken
No you don't have it quite right.
The fuel is traveling the same speed as the airplane. It will "lay flat" along the bottom, if the plane noses down, the fuel flows downhill starving the engine.
The only time that the fuel stays at the back of the tank is when the plane is accelerating at a relatively high rate (say 6/8 "G" dependant upon inclination). Then inertia kicks in.
This is pure physics...
There is no problem with the clunk traveling forward provided that it cannot get entangled or stuck. If anything this is preferable as it permits the clunk to remain where the fuel is.
The fuel line does not get pinched if you have things set up right... especially it's length.