Roto Flow fuel tank

[stangflyer]

Silver Fox;17350 wrote: I guess seeing is believing. This should answer your question of what actually happens inside your tank on a downline. Adjust your clunk accordingly.

Wayne



http://m.youtube.com/watch?v=WtbSqEtLQX4

Ohio AV8TOR;17364 wrote: Have you even flown full scale aerobatics or been in a plane doing a downline or hammerhead? Down lines are negative G's not positive. Gas in our tanks are more influenced by gravity than G's. G's just make the fuel weigh more and have more pressure in the position gravity puts it.

Actually, no...I've never flown full scale aerobatics. I'm pretty sure I said "G" force and not referencing neither positive or negative. That being said, after viewing the video....it seems all information I have ever read or been told goes right out the tail pipe with the exhaust. I actually argued this very point with my son at one point. Very interesting to see it "live".

 

[Ohio AV8TOR]

Yes that video speaks volumes

 

[stangflyer]

Silver Fox;17350 wrote: I guess seeing is believing. This should answer your question of what actually happens inside your tank on a downline. Adjust your clunk accordingly.

Wayne



http://m.youtube.com/watch?v=WtbSqEtLQX4

Ohio AV8TOR;17457 wrote: Yes that video speaks volumes

Yes it does. I am glad Wayne posted it.

 

[orthobird]

i have had 5 of these tanks, and at first, they all did pretty good. after some time, i started to notice erratic operation of the engine after 5 minutes of flight or so.



i removed the tank,and problem went away.,



i have a good buddy, and he has one and his friend has one also. both say they have absolutely no problems.



so i determined, that my tanks, once fuel level gets under level of the brass tube that runs length of the tank, the seal on the rotating clunk must be going bad on mine, allowing air into the brass tube and thus bubbles in my fuel line that goes into the carb.



why did my fail within one year and not my buddies? i do not know, except, i asked them, they both use TRUFUEL. i use 88 octane gasoline from the pump and i mix in redline oil. we can guess that the ethanol in the gasoline destroyed the rubber seals in my tanks, whereas they were running unleaded and un ethanol fuel. just my 2 cents. i am not knocking those tanks, and the guy who sells it gives great service. Would be interesting to know from him if they have upgraded their seals so that they are resistant to ethanol in the gasoline.

 

[stangflyer]

I was wondering about the ethanol fuel. It seems like a bit of a "pita" to drive 12 miles to get my 90 octane non ethanol fuel. But I see the difference in how my motors run as opposed to some of the other guys. I didn't think it would make much difference at first, yet I do now. Maybe that is the cause of the seal failure??? Would be interested to know.

 

[TazmanianDevil]

Off topic. Speaking of gas, I come from Israel and we fly here standard 95 unleaded without ethanol. The higher grade is 98 unleaded with no ethanol. When I first came to the NATs 2013 I've noticed that your gas do effects the engine performance this year at the worlds I saw it again at first I thought it's the weather but now I do the math and it seems to me it's the gas.

Back here the engine is a rocket.

Adi

 

[orthobird]

TazmanianDevil;17723 wrote: Off topic. Speaking of gas, I come from Israel and we fly here standard 95 unleaded without ethanol. The higher grade is 98 unleaded with no ethanol. When I first came to the NATs 2013 I've noticed that your gas do effects the engine performance this year at the worlds I saw it again at first I thought it's the weather but now I do the math and it seems to me it's the gas.

Back here the engine is a rocket.

Adi

wow Adi that is impressive!! so the gasoline you put in your car is 95 and 98 octane?

 

[BikeRacer]

Thats really interesting about the higher octane fuel. I'm a mechanic so I was always taught that you will lose power if you increase the octane because it burns slower. Then only time you need higher octane is when the engine has higher compression or other factors that require it. I have heard several stories though like this one or guys running AV gas and swear that it runs better. I wish I new the true science behind octane.

 

[SlowHuck]

BikeRacer;17736 wrote: Thats really interesting about the higher octane fuel. I'm a mechanic so I was always taught that you will lose power if you increase the octane because it burns slower. Then only time you need higher octane is when the engine has higher compression or other factors that require it. I have heard several stories though like this one or guys running AV gas and swear that it runs better. I wish I new the true science behind octane.

My guess is that engines run better on Avgas because of the lead. Better lubrication, thus cooler and quieter operation. When I was actively flying FS, I would ride my old Ironhead Sportster to the local county airport and keep it topped off with 100LL from the airplane pump. Ran much smoother and quieter (considerably less valve tapping). As an added bonus, it smelled like an airplane!

 

[orthobird]

Ant;17405 wrote: I know for a fact my clunks all stay at the back of the tank, because I put a drinking straw over the fuel line to prevent it from going to the front. been doing that for 3 years and never had a problem and I fly hard.



In my opinion, you don't want the clunk line getting curled up, or what if it did go to the front and get hung up, then you go into a hover and bye bye engine.

and airplane too!!!