whiskey29

Hi guys,
I have used bubbles less tank with pylon plane (with carbs) and i put the tank under the wing which is about 13inch away from the carburetor and it work just fine thru out the whole tank, but its just small 130cc tank.
I want to build pusher or tractor rc jet (prop) with 260cc tank, and I need to put the tank somewhere near the cg which is further away (about 20inches away) than my pylon setup. Has anyone tried something like that before ?
thanks

jaka54

Hi!
I think you have to try this out for yourself because there are very few modelers here that have used Tettra "Bubble less" tanks.
In pylon racing they are mandatory to have a reliable engine run, but using one as far as 50 cm from the engine could be too far away.
In my "Pushy Cat" racer, based on the 1989 Formula 1 winning Reno racer I have the 150cc Tettra tank mounted 20cm from the carb on my .40 R/C engine and that works well.

1QwkSport2.5r

It all depends on the engine and how well it draws fuel. If you have an R/C throttle, it may not work well enough due to fuel draw at lower throttle. If it’s a fixed throttle engine, it will probably work since the tank pressure will be more consistent. I’ve ran a sport .46 on a standard tank and a Tettra tank 6” below and 7” behind the engine and it ran fine (Jett tuned muffler was used, which has higher tank pressure than OEM muffler). However, priming and starting the engine was a pain due to being inverted. My engine had a small carb though. Set the engine up on your test stand and try to set the fuel system up how it would be in the plane and test the engine. Run several tanks of fuel to get a good feel for whether it’ll behave or not. It may, or it may not.

FWIW: I use a 10oz Tettra tank with my Jett .56LX (full wave piped) powered outrigger airboat that’s 4” below the engine and it will suck the tank dry no problem. I don’t know that it would run as well with the tank much farther away though.