Flexible Needle Valves?

Levent Suberk Mon Mar 23, 2020 1:58 pm

Are these flexible needle valves available for Cox engines? What are the advantages and disadvantages?

Marleysky Mon Mar 23, 2020 2:19 pm

#1 Advantage (IMHO) is getting your fingers away from spinning prop.
#2 would be the extra length to get outside the cowling.

I have some WenMac/Testors NV with braided wire “flex” cable, do not recall seeing anything like them from Cox, other than pushing flex fuel tubing over nV.

aspeed Mon Mar 23, 2020 3:52 pm

I've never seen one for a Cox. Besides the obvious advantage, I like the short ones best, like the Russian combat motors. They won't get bent, and are lighter. I've seen the long ones vibrate like crazy at certain rpms. Having said that, the OS have a sleeve that you can put in a piece of wire for an extension. It tightens with a set screw. I have used a piece of leadout wire with a wheel collar for a knob to adjust from outside the cowl. A Cox needle could be cut off a bit and a sleeve with two set screws used to add an extension. If there is just a little nub sticking out, then a crash would only bend the flexible portion. Not something I would do normally.

Jason_WI Mon Mar 23, 2020 4:20 pm

There is a flexible needle valve used on one of the Cox cars back in the day. I have one and I think there is a picture of one in the Cox engine handbook.