Nitro doesn't suck. Exhaust pressurizes the tank pushing the fuel through.
Pkugging vent lines is exactly one of the reasons to stay away from the octane tank. Another is tge fuel cap.
The smallest pressure leak will cause tuning issues.
to avoid a peeing contest i agree to disagree, we both have different experience i'm not going to throw out a i ran this for x years just going to give my 2c
nitro carbs as virtually every carb petrol/gas or otherwise will use the venturi effect in some way or another, yes nitro use the exhaust line for extra pressure as some gas use a fuel pump, a nitro can run without extra pressure like gas but may endup being lean and endup being a pain to tune
as i said i would use the return line to pressurise the tank, ( black tube on the octane tank )
the fuel tank cap will be fine i doubt hpi would allow a tank to be designed where fuel could slosh around and escape from around the cap,
think of a gas grass trimmer/weedwacker and the way most of the tanks are orientated when in use more often than not fuel is sitting against the cap but not leaking out but usually seeping from the vent, it's just common sense for a fuel tank to have a good seal on the cap for the safety of the operator
plugging the vent hole or tube if it has one ( doesn't look like it from what i can see ) that will ensure the tank stays pressurized if it does have a hole use a screw with a suitable O'Ring/grommet if its a hose use a stopper that's common for plugin nitro fuel lines
i'm using a 400cc aircraft tank mounted behind the engine of my savage, all i had to do was plug the 3rd hole for the filler tube with a nut and bolt, its airtight and works perfectly although a little unsightly but it fixed the annoying mid tank lean issue and doubled my run time
just have to think outside of the box just because something is made for one application does not mean it can't be used for another, nothing wrong with trial and error
we both have differing opinions and methods to do it both are valid one just uses some improvisation and modification, just depends on how you look at it and how you want to execute it
from looking at it i know it may look like it would work i thought that when i initially thought about converting to the octane platform but after i looked into it it was pretty straight forward although it will need some modification for the position of the engine as the octane engine has a larger footprint and different mounting points on the engine plate
it is doable but the required modifications are not really worth the benefits if any of the octane chassis other than the option to fit the 15cc gas engine in the future
Sorry for the long post didn't expect to type a wall of text,
