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Engine basics => Engine set up tips => Topic started by: Allen Eshleman on July 06, 2015, 07:20:27 PM

Title: Smith Needle Valve shortening
Post by: Allen Eshleman on July 06, 2015, 07:20:27 PM

Has anyone shortened a Randy Smith needle valve?

I have thought of cutting one off and putting a piece of 3/8 balsa on the end, glued on with epoxy or thick CA.  The idea is to make a round piece about about 3/8 inch thick both ways, drill a small hole just a bit smaller than the needle stem.   

Another way would be to cut it and bend it but that is good stuff.  Too hard to bend.

If I wasn't hauling in tight quarters and meeting the ground too often, I wouldn't need to do this.

Title: Re: Smith Needle Valve shortening
Post by: RknRusty on July 06, 2015, 10:19:02 PM

I cut a ST needle to a stub and secured a wheel collar on it with a 4-40screw that was long enough to get a grip on when tuning it. I added some JB weld just as added security.
Rusty

Title: Re: Smith Needle Valve shortening
Post by: bob whitney on July 07, 2015, 08:10:25 AM

  cut the needle about 3/8 longer than u want it . thread it into the spraybar , use a propane tank to heat up the end of the needle cherry red and bend it ,let it cool and u are good to go

Title: Re: Smith Needle Valve shortening
Post by: RandySmith on July 07, 2015, 08:56:51 AM

Quote from: Allen Eshleman on July 06, 2015, 07:20:27 PM

Has anyone shortened a Randy Smith needle valve?

I have thought of cutting one off and putting a piece of 3/8 balsa on the end, glued on with epoxy or thick CA.  The idea is to make a round piece about about 3/8 inch thick both ways, drill a small hole just a bit smaller than the needle stem.   

Another way would be to cut it and bend it but that is good stuff.  Too hard to bend.

If I wasn't hauling in tight quarters and meeting the ground too often, I wouldn't need to do this.

Hi Allen

the needle is bendable, I have no problems bending them , as they all come straight, try a vise or vise grips if you have trouble, not on the threads though :-)

Randy

Title: Re: Smith Needle Valve shortening
Post by: Allen Eshleman on July 07, 2015, 01:08:42 PM

Thanks Randy, Bob and Rusty,

I know what I need to know.  I have one straight extra.

Title: Re: Smith Needle Valve shortening
Post by: Steve Helmick on July 09, 2015, 06:28:12 PM

FWIW, it's that angled "handle" that makes the NV tend to unscrew itself. A long needle with a heavy knob on it will likely break off at the end of the threads. Dirt sometimes used an R/C car pinion gear for a knob. Mine broke the NV off when I tried that. They're not cheap, but if you can get some worn-out ones from R/C car guys for nothing, it'll do, if you can keep the NV short.

Randy's NV Assys are THE BEST.   y1 Steve

Title: Re: Smith Needle Valve shortening
Post by: Allen Eshleman on July 11, 2015, 02:15:13 PM

I found a cutter that I have which was able to cut a Smith needle and I did it.  Then I used Rusty's idea and put on a hub with a screw in it.

Agreed Steve, Randy's nva's are the best.

Title: Re: Smith Needle Valve shortening
Post by: RknRusty on July 11, 2015, 09:22:26 PM

Allen, glad you liked my idea. I hope it works well for you.
Rusty

Title: Re: Smith Needle Valve shortening
Post by: Allen Eshleman on July 11, 2015, 09:26:18 PM

I soaked mine in super glue.  I hope that holds.