News:



  • June 14, 2025, 10:11:43 AM

Login with username, password and session length

Author Topic: FOX 35NEEDLE VALVE  (Read 1368 times)

Offline Bob Disharoon

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 448
FOX 35NEEDLE VALVE
« on: April 07, 2007, 04:15:36 PM »
Just got a new NVA from Fox..the spraybar has one hole and the needle tip is rounded at the bottom, lacking the old flat spot..is this something new and and will it make any performance difference? I really hope this is the last Fox question....think Ive finally asked all of em..thanx, BOB ???

Offline Bill Gruby

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 1488
Re: FOX 35NEEDLE VALVE
« Reply #1 on: April 07, 2007, 04:36:25 PM »
Hi Bob;

  Best advice I can give you on this one is install it -- see what happens-- if it doesn't work then give us the info on what happened and then ask your question again. Armed with the info you will get it will be easier to help you diagnose your problem. OK

  "Billy G"   H^^
Bill Gruby
AMA 94433
MECA 5393-10

Offline peabody

  • 23 supporter
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 2866
Re: FOX 35NEEDLE VALVE
« Reply #2 on: April 07, 2007, 05:23:09 PM »
They work fine.....poke the hole towards the crank....

Offline Bob Disharoon

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 448
Re: FOX 35NEEDLE VALVE
« Reply #3 on: April 07, 2007, 05:34:36 PM »
Thank you, MR. Peabody..thats excactly the answer I needed, before I broke the package open. Out of curiosity..any idea when Fox made this change?..thanx in advance..BOB

Offline Jim Thomerson

  • Trade Count: (0)
  • Admiral
  • ******
  • Posts: 2087
Re: FOX 35NEEDLE VALVE
« Reply #4 on: April 08, 2007, 06:26:52 AM »
This is the story as I recall it, so don't hold anyone else responsible (me either).  Think it was around 1990, anyway, after Duke passed away.  Replacement NVA's are one of the things engine makers make money on.  John Lowery showed Betty Fox that all the Fox engines at a contest had other maker's NVA's installed.  Design was changed. 

I haven't flown the new Fox NVA's to comment on them.  The previous Fox 35 stunt NVA's did not work for me.   I would fly three flights in a row and get three different engine runs without touching the needle. 

Offline Marvin Denny

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 889
  • Welcome to the Stunt Hanger.
Re: FOX 35NEEDLE VALVE
« Reply #5 on: April 08, 2007, 09:59:18 AM »
  The new uniform taper needles are a little easier to get a good setting with, but are STILL too loose in the threads to keep a good setting without putting a short piece of fuel tubing around the threaded portion between the ratchet knob and needle body face to get and maintain a seal.  They DO screw in a little farther to get the setting and so stay a little more shake proof than before.

  Bigiron
marvin Denny  AMA  499

Offline Scott Hartford

  • Trade Count: (0)
  • Commander
  • ****
  • Posts: 350
Re: FOX 35NEEDLE VALVE
« Reply #6 on: April 11, 2007, 10:01:07 PM »
QC is still somewhere between non-existant and third-world. ::) The last one I pulled new out of the pack had such poor threads on the spraybar to mounting nut I thought it was going to strip with very little pressure so I tossed it and used a ST. ~^

Offline L0U CRANE

  • AMA Member
  • Trade Count: (0)
  • Admiral
  • *
  • Posts: 1076
Re: FOX 35NEEDLE VALVE
« Reply #7 on: April 12, 2007, 12:44:17 PM »
Bob,

There are a few other nice NVA available, which are closer to the OEM Fox spraybar diameter. The ST and a few others' spraybars are significantly larger diameter, which may cause some loss of power - if that is a consideration.

I like the OS and ENYA sets. ENYAs are a bit tricky to locate, but OSs are available from Tower. Either of these will most likely require some 'packing' to center the spraybar hole in the venturi. I use aluminum "backup washers' available for pop riveters: light, soft (easily drilled that last bit to fit smooth and snug), and thicker than brass or nickel plated common washers.

The Fox spraybar is around 0.125". ST is over 0.140". ENYA and OS are around 0.130". The stock Fox 35 venturi minimum diameter is a bit over 0.250", so a bigger spraybar can really restrict the flow. Yes, better 'fuel draw,' but if it cuts power too much, that's not a big help.

Prices are not out of line, either...
\BEST\LOU

Online RandySmith

  • Administrator
  • Trade Count: (0)
  • Admiral
  • *****
  • Posts: 13756
  • Welcome to the Stunt Hanger.
    • Aero Products
Re: FOX 35NEEDLE VALVE
« Reply #8 on: April 12, 2007, 01:13:55 PM »
Just got a new NVA from Fox..the spraybar has one hole and the needle tip is rounded at the bottom, lacking the old flat spot..is this something new and and will it make any performance difference? I really hope this is the last Fox question....think Ive finally asked all of em..thanx, BOB ???

HI Bob

There is a NVA that is a perfect fit for the FOX 35, it was made to go into only that motor and is Stainless Steel, with a Stainless needle, perfect fits  and  has a  seal under the lock collet, you don't have to file, shim, pack, or plate.....etc...
I have them here, they are the same type as the ones I put in my PA engines

Regards
Randy

www.aeroproduct.net

Offline Bob Disharoon

  • Trade Count: (0)
  • Captain
  • *****
  • Posts: 448
Re: FOX 35NEEDLE VALVE
« Reply #9 on: April 12, 2007, 01:36:46 PM »
Thanks Randy..I did not see it on your site, but would like to order one and need the cost. could you PM me with the info?..thanx again....Hoosier D.

Tags: