NVA

Hello all,

Lately I've been trying to find an inexpensive source for needle valve assemblies. I have a lot of engines converted from R/C and have almost exhausted my supply of NVAs. What I would like to find is one type that will fit a range of engines from .25 to .40. The diameter of the spray bar is my concern. I can modify the venturi. My goal is consistency of spray bar diameter. I see ST NVA's for sale on the bay for 20 bucks but that is double my budget, it really is painful to spend more for a NVA than what I pay for an engine. If I must I would be willing to tap the venturi for an R/C type NVA and set it up as a "dribbler, but would rather have the conventional C/L type setup.

LAST EDITED ON May-09-04 AT 09:22 AM (CDT)
 
Tom,
Have you ever heard of Stuka Stunt Works? They have a wide variety of needle valve Assys., venturis, mufflers and other stuff --- all worth the money. Check with our host, Leonard Neumann at Stuka Stunt Works.

Don,

I was sorta hoping for a response from the good folks at stuka. I know they do fine work. As posed in my question above, I am looking for a "one NVA fits all" and hope I can adapt one as a generic for all my various size OS's.

Even though this forum belongs to Leonard, he will not toot his own horn, so it is up to the rest of us to toot it for him. Send him an Email about what you want.

>Don,
>
>I was sorta hoping for a response from the good folks at
>stuka. I know they do fine work. As posed in my question
>above, I am looking for a "one NVA fits all" and hope I can
>adapt one as a generic for all my various size OS's.
>
>Tom

The only problem with a "one NVA fits all" is that there is a difference in the width of the case of various engines and also a difference in the cross hole on some. And there is no consistency. The Fox 35 uses a .125 needle and the current Fox 40 uses a .155.

On the old OS engines the 20/25 engines used a .125, the 40 used a .135, but the 35S used a .155. And the .40 used a longer one, just to keep things confused.

On the present crop, the 20-40FP and the 25-46LA all use the same .135 needle. I have OS needles of .135 diameter for the FP/LA series and .155 diameter OS needles for the 35S.

The most universal needle, however, would probably be the ST. These are made in small, medium, and long lengths, however, to accomodate the various widths of the engines. For engines that use a smaller cross hole, you can drill these out, and resize the venturi accordingly. You may wish to get different lengths of these, although you can use spacer washers (which I also have) if you simply want to use the longer ones on everything. Longer needles cost more, however, although not nearly what you quoted from e-bay.

I send you an e-mail on these, but thought I would post this here as it was more pertinent in answering your question.

I just bought a bunch of ST 51 NVA (with needles) from Tower. Price was reasonable, $8.99 and they qualify for the $3.99 "Parts Express" shipping.

Thanks for the help all. Leonard has fixed me up. I was using different types of NVA's from my parts box of 35 years ago. They work ok but there are hardly two the same diameter. I have use of a lathe now and I started makeing different sized throats on the venturi depending on the NV diameter. I decided this is madness. I really can't tell the difference of the throat diameters of the venturi by eyeballing them so I wanted to set them up the same on the same engine type. I have mostly OS MAX 40-H and OS MAX 30-S engines. My 40 FPs already have the stock C/L NVAs. I was thinking about selling the R/C carbs to help pay for the NVAs from Leonard. I may have to take them over to R/C field next week.

I see you'r fixed up now, but for future reference it sounds as if what you really want is the old "universal" NVA, which has a thread and nut each end instead of being fixed one end. Not sure who does these these days, but they are around.