I've been back at c/l flying from the 60"s for only a short time (about two years) and am trying to catch up on what's what.

It seems that ST nva's are favored by many.  My question is: "What is the reason for this preference?"  I'm not "doubting" anything.  Just would like to know the particulars.

As a casual observation, it seems that the 90* bend on the end of the ST needle is more likely to cause someone to turn their knuckle(s) into the backside of a spinning prop.  Seems safer to "twist"  a knurled cap than to "turn" the "L" bend on the needle.

Thanks,

Joe

I kinda like the K&B Universal NV assembly for sport models, tho when I crash, the needle survives, but the spraybar breaks. To get sorta serious, I much prefer the PA (aka Randy Aero) Needle Valve Assembly. It's like the ST, but has a plastic cone instead of a split collet design. The difference is very apparent when using it. The nut can be very tight, but the needle can still be turned, a good thing. You can get them from Randy or Leonard.  Steve

I only get PA needle valve assemblies from Randy at Aero Products now.  He has them made for all size engines.

They have all the features of the ST, but like Steve pointed out, they have a nylon cone in the needle locking nut.  That allows the nut to only be finger tight (my fingers) and the needle will not turn unless you turn it.  The nylon cone also insures there are no air leaks there.

The needle locking nut on the ST NVA can get loose after a while and tightening it enough to keep the needle from turning while the engine is running gets to be a pain.

Bill <><

What is the spraybar O.D. of the PA needle valve assy.?

.157  same  as  a  ST   or  the   OS  FSR  NVA , the only  exception is  the   SS  FOX  PA  style  it  tapers  down to  127   same  as  a  FOX

Regards
Randy