Fox,35 NVA options

[Lyle Spiegel]

I'm  interested in updating my Fox 35 stunt with collet style NVA. Have been told ST style from PA (Randy) and RSM (Eric) no longer available. Any suggestions for other NVA? Will the NVA for  Brodak 25 work ok ? Other ideas?Thx

[Bill Little]

Hi Lyle,

Steve Wooley and the guys use to use an OS NVA.  The old one, not the ones for the FPs and LAs.  I think Leonard Neumann has some.  It is, of course, bigger in OD in the venturi throat, but they used them stock.

BIG Bear
RNMM/AMM

[Motorman]

There are improvements you can make to the Fox unit. Cut off the top knob and bend the stem 90 degrees. cut a piece of thick silicon tubing that will seal between the needle and the spraybar. The trick is to get the right length for the needle setting you're using and not squeeze it too much or leave a gap. These two things will help stabilize the needle from vibration and seal air leaks. You can also use teflon paste on the threads but it will stiffen up the needle when it dries.

Years ago I got a few after market supertiger NVA from Len on Stuka that had the fuel discharge hole drilled in the wrong place. Don't know if he ever fixed that problem but the hole is supposed to be down stream of the valve seat so check it if you go that route.

MM

[Trostle]

the hole is supposed to be down stream of the valve seat.

MM

Not so if you want maximum fuel draw.  If it is spray bar with a single hole, the hole should be approximately 30^o to downstream through the venturi.

Just saying.

Keith

[eric rule]

Lyle:
I do not know who told you that the ST needle valve assemblies are not available but they are wrong! I currently have in stock all three sizes of spray bar plus over 3000 needles.

For your Fox .35 engine you need the STNVA (cost is $9.99 for the complete assembly). This is the one used in the ST51 and is the shortest of the three lengths. Medium length spray bar (used in the ST 46) is STNVA46 and costs $14.99. The longest spray bar is STNVA60 (used in the ST 60) and costs $16.99

Eric Rule
RSM Distribution

[RandySmith]

I'm  interested in updating my Fox 35 stunt with collet style NVA. Have been told ST style from PA (Randy) and RSM (Eric) no longer available. Any suggestions for other NVA? Will the NVA for  Brodak 25 work ok ? Other ideas?Thx

Hi Lyle

Yes you got bad information, many NVAs are availible  from multi sources, Although I do not have the Stainless Steel PA/Fox  NVAs in stock, I do have the  ST, and the new OS ( which is much closer in size to the Fox diameter), and maybe A couple of KK NVAs,
you can get what you need from me , Eric Rule, and others, with the OS you only need use 2 washers, with the  ST you will either need to drill the Fox venturie bore, or file the sides of the Spray bar down. do NOT  turn it down on a lathe, it will break

Randy

[Motorman]

Not so if you want maximum fuel draw.

If you want to actually meter the fuel, the discharge hole has to be down steam of the valve seat on a SuperTiger NVA. If it's up stream it becomes a sliding valve that doesn't work right because, the hole/needle size and needle taper are wrong for a set up like that. I've never had any problem with fuel draw from the SuperTiger NVA but, I have had problems keeping a setting with units that weren't made right.

MM