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 Needle and seat modification 
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Joined: Wed Jan 29, 2014 12:00 am
Posts: 64
Hello Everyone,
I have many .100" viton tipped holley needle and seats, and was thinking about opening them up to
other sizes, either to .110" or .120". The thought was to cut off the lower crimp and remove the needle before drilling. My only concern is, should the needle seat be touched up, to ensure it seals?
I would think, the needle may seal tighter by reducing the seat area..? Has anyone on here had luck opening them up?
Thanks


Wed May 31, 2017 4:27 pm
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Joined: Wed Jul 02, 2014 6:17 pm
Posts: 545
Alkyvette wrote:
Hello Everyone,
I have many .100" viton tipped holley needle and seats, and was thinking about opening them up to
other sizes, either to .110" or .120". The thought was to cut off the lower crimp and remove the needle before drilling. My only concern is, should the needle seat be touched up, to ensure it seals?
I would think, the needle may seal tighter by reducing the seat area..? Has anyone on here had luck opening them up?
Thanks


At $8-9 each I personally wouldn't.............. :thumbr:


Wed May 31, 2017 4:47 pm
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Joined: Fri Feb 08, 2013 2:37 pm
Posts: 1744
Not a problem, I do it regularly to make large inlets (.130" +) to use with spring needles. It is best to drill in a lathe, but I have done by hand with a drill motor. After drilling, deburr with a stick of wood, wooden chopsticks are good for this, and then a twist of ScotchBrite, then, drop a 3/16" steel ball (vacuum secondary check ball, QJet accelerator pump check ball) in the orifice and tap the ball lightly using a brass rod and small hammer or the side of your needle-nose pliers. The ball will swage a smooth seat. Test by assembling in a bowl with a fuel line and suck a vacuum on it. If it holds the vacuum it is OK and will hold fuel pressure.

You can make big inlets for QJets this way too, .150", .160"+. You can make the seat bigger than the rubber tip, but you need to drill the rubber tip out of the needle in a lathe so the drilling is centered. Drill the needle with a 3/16" drill and that will leave the three ribs on the side of the needle to act as guides for the 3/16" ball used to replace the rubber tip.


Wed May 31, 2017 6:21 pm
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Joined: Wed Jul 02, 2014 6:17 pm
Posts: 545
tuner wrote:
Not a problem, I do it regularly to make large inlets (.130" +) to use with spring needles. It is best to drill in a lathe, but I have done by hand with a drill motor. After drilling, deburr with a stick of wood, wooden chopsticks are good for this, and then a twist of ScotchBrite, then, drop a 3/16" steel ball (vacuum secondary check ball, QJet accelerator pump check ball) in the orifice and tap the ball lightly using a brass rod and small hammer or the side of your needle-nose pliers. The ball will swage a smooth seat. Test by assembling in a bowl with a fuel line and suck a vacuum on it. If it holds the vacuum it is OK and will hold fuel pressure.

You can make big inlets for QJets this way too, .150", .160"+. You can make the seat bigger than the rubber tip, but you need to drill the rubber tip out of the needle in a lathe so the drilling is centered. Drill the needle with a 3/16" drill and that will leave the three ribs on the side of the needle to act as guides for the 3/16" ball used to replace the rubber tip.


Man, you guys have got some time on your hands then cos it seems like a LOT of work but maybe not for you bad asses...........any pics of the mods........... :thumbr:


Wed May 31, 2017 8:05 pm
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Joined: Fri Feb 08, 2013 2:37 pm
Posts: 1744
If you think that is a lot of work, perhaps you need a different hobby, maybe quilting or needlepoint, something that will give you proper lessons in time consuming.

If you are serious about getting over rough terrain in desert racing or rough water with a boat, you need the correct bucking spring properly adjusted and a spring needle in a large enough seat orifice to supply the required fuel at low pressure, 3 or 4 lbs. Where are you going to buy a .130" inlet with a spring needle?


Wed May 31, 2017 9:36 pm
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Joined: Wed Jul 02, 2014 6:17 pm
Posts: 545
tuner wrote:
If you think that is a lot of work, perhaps you need a different hobby, maybe quilting or needlepoint, something that will give you proper lessons in time consuming.

If you are serious about getting over rough terrain in desert racing or rough water with a boat, you need the correct bucking spring properly adjusted and a spring needle in a large enough seat orifice to supply the required fuel at low pressure, 3 or 4 lbs. Where are you going to buy a .130" inlet with a spring needle?



Didn't expect that smart ass answer but ok..........and who said anything about fing springs? I get it, enjoy and maybe YOU should take up those hobbies as it may make ya less grumpy.......................... :wft?:


Wed May 31, 2017 11:56 pm
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Joined: Fri Feb 08, 2013 5:50 pm
Posts: 2363
Anything worth doing right can be time consuming. Some carbs you can make out decent with, occasionally you take a loss to learn. I've spent a ton of time on a flow bench with carbs, and will likely never recoup that time.


Thu Jun 01, 2017 9:51 am
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Joined: Mon May 06, 2013 9:32 pm
Posts: 101
Mark I sent you a PM last night. Did you get it?


Thu Jun 01, 2017 9:58 am
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Joined: Wed Jul 02, 2014 6:17 pm
Posts: 545
jmarkaudio wrote:
Anything worth doing right can be time consuming. Some carbs you can make out decent with, occasionally you take a loss to learn. I've spent a ton of time on a flow bench with carbs, and will likely never recoup that time.


The subject was "Needle and seat mods" NOT how to build/mod a carb and trust me, I spend lots of time and EVERYTHING goes under my dental lab bad ass light/magnifying glass and then ran on my car and you can see the messes I find on my FB page plus 99% are "Cleaner and Meaner" and several have won races, runner-ed up or even won Drag Week so I GET IT..............Never gave sewing a chance but maybe when I'm old and crazy, then I'll get back w/you guys............... :thumbr:


Thu Jun 01, 2017 10:44 am
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Joined: Fri Feb 08, 2013 2:37 pm
Posts: 1744
Aww Thumper, now you've gone and hurt my feelings. There you go taking everything so serious. Needle point is fun but knitting is more likely to have a calming effect, sort of like tatting, perhaps you should try either one, unwind a little, your shift light is blinkig.

Since you want to take everything so literal, check the thread title. It says "Needle and seat modification" but you say you don't have time for modifications because the easy way is only $8 ....... to wit, "At $8-9 each I personally wouldn't....." ..... so what are we to think?

P.S. I see t compliments you get from people for your carb work, so you don't need to be so quick to think you have been impugned over something so simple. (note to self: wear kid gloves when teasing Thumper and use the sarcasm smiley liberally because his leg is numb and he can't feel it when you pull it)


Thu Jun 01, 2017 12:06 pm
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