Fill tube dimensions - WCH I110

[hybridfreak]

Hello,

I want to get my good old West Coast Hybrids I110 flying again but I am lacking a couple of parts.

I can source all I need but I'm lacking some information regarding the fill hose/injector size and don't have a hose to measure.
The instructions say 5/32" fill hose, which I have found with different inside diameters. Can anyone tell me which one is the right one?
I've found from 2 to 2,7mm ID (0,08" - 0,11"), which is quite the range

Thanks!
Roman

 

[OzHybrid]

At 5/32 any nylon tube should be ok pressure wise. But it affects your injector size as the tube is the injector. If you can find the (expired) West Coast Hybrids website address, you might be able to use the wayback machine to get the manuals.... then search for www.westcoasthybrids.com in the wayback machine. It's a great resource.
If you cannot find the manual, go with the smallest bore as it will be the highest pressure one.
As you're in Germany, you might want to consider changing to 4mm air line and fittings if you cannot get the imperial size easily.

Looks like the West Coast Hybrid is using the compression ferrule internal to the tank volume. This will reduce the available nitrous by the encroachment into the tank volume.
The 2006 save of the website has some information.

https://web.archive.org/web/20061107095416/http://westcoasthybrids.homestead.com/home.html

 

[hybridfreak]

Thank you!

I did find the manual, that's where I got the 5/32" from. A member on a German forum found which hose is most likely used:

https://ph.parker.com/us/en/product/flexible-nylon-tubing-n-series/nn-2-5-025
So it's very likely they used the 0.0106" ID hose but using the ferrule the ID is somewhat random.

I think in the end I'll run some numbers and do some CAD to make my own internals pretty sure that I110 casing can output way more than 428Ns!

Cheers,
Roman

 

[OzHybrid]

Thank you!

I did find the manual, that's where I got the 5/32" from. A member on a German forum found which hose is most likely used:

https://ph.parker.com/us/en/product/flexible-nylon-tubing-n-series/nn-2-5-025
So it's very likely they used the 0.0106" ID hose but using the ferrule the ID is somewhat random.

I think in the end I'll run some numbers and do some CAD to make my own internals pretty sure that I110 casing can output way more than 428Ns!

Cheers,
Roman

The Rattworks I90 uses 1/8"OD nylon hose as fill and injector. Hybrids are not super sensitive to injector size changes. You just produce a bit more or less power, unless you go silly. So a size somewhere in between will probably be ok. Main thing is to never have your combustion chamber pressure greater than your tank. That's bad...

 

[hybridfreak]

The Rattworks I90 uses 1/8"OD nylon hose as fill and injector. Hybrids are not super sensitive to injector size changes. You just produce a bit more or less power, unless you go silly. So a size somewhere in between will probably be ok. Main thing is to never have your combustion chamber pressure greater than your tank. That's bad...

Good info! I think I'll go with an oversized fill hose and restrict flow between hose and tank using carburetor jets. They're cheap, small and available in all kinds of sizes. That way I can quickly adjust injector to nozzle size and have different thrust curves