ORIGINAL: RC11
Matt,
Where do you get Viton and what clunk are you running?
Slightly off subject but..... People think the clunk and clunk line must be able to follow fuel and be able to bend in a downline to go to the front of the tank. I don't think this is possible. If you have ever dinked one in and the clunk is in the front of the tank, it can be difficult get the fuel line and clunk beat around back to it proper possition in the back of the tank. So I am doubting the clunk is that mobile. If you hold your plane nose down and look at the clunk it will at best bend to the upper limits of the tank. What are the dynamics of fuel and the clunk in a downline? I gots to know!!!
Thanks Proffessor,
RC can other classmates chime in also?
Hi, Rick,
I agree that the clunk is not all that mobile, nor should it be. When you think about it, when a model is descending (with engine at idle) the liquid in the tank is "feeling" virtually zero gravity, so neither the fuel nor the clunk are going to the front of the tank. However, I store my models in a small utility closet and I must store them with the spinner down, which means with soft fuel line the clunk can work its way to the front of the tank. This happened, and I lost a nice model (RC Guys Decathlon) because of it, so now for the fuel pick-up line I use a brass section in the middle so that there is no chance the fuel line can fall forward in the tank.
When I used to fly smaller aerobatic glow models and fling them about the sky, occasionally bubbles would get into the line and there'd be the occasional deadstick. I started using OS Bubbleless clunks and that was the end of that. The engine will run down to the last drop with no change in performance. I don't know if it's necessary for pattern, but that's what I use with all gas and glow fuel systems because it removes any doubt.