I'm going through my centerdrain NH. I've drilled out the 3 brass plugs and cleaned the passages. I've got it all apart except removing the throttle and choke shafts. They have no noticeable slop, so I saw no reason to remove them. I want to install a new float valve, but would like your thoughts on pros and cons of the viton tipped valve vs the so called original spec valve. I want to ensure that I get full fuel flow. Does the viton valve have a smaller passage than the other? If so can the seat be drilled out to the correct size for better flow? The so called original spec version has a stainless steel needle - is this original? I've read Stan Howe's comments about the rough finish on the currently available original spec needles and seats and all the work he has to do to make them seal properly. So I'm a little gun shy of these. I'd appreciate your thoughts on these. Thanks.
To my knowledge and a bit of experience there's no fuel shortage with the Viton needle. Other's may chime in.
I have always used the Viton tipped needle with great success.
The main precaution is when you set the float height. Old school guys like me had a bad habit of using a screwdriver to force the valve shut and bend the float arm to achieve the correct height. This damages the seat area especially the soft seat versions with troublesome results.
Larry Smith makes a new repro of the original version, and it works great. (RV Anderson also makes them for the Holley G.) They both are sold thru Lang's and Snyder's. Some other manufacturers' might not work as well. When You call in your order, ask whether the ones they carry are made by Larry or RV or someone else. If you don't get the right answer, go elsewhere. The original type won't deteriorate like the rubber-tipped ones.
Thanks for your comments guys. Are the Viton tips used currently any more resistant to today's fuels than those made a few years ago? I've seen a lot of comments in the archives about the tips deteriorating after a couple years or less.
Has anyone else had problems with the new original spec valves leaking due to a poor finish on the needle tip or seat? Thanks.
I have had no problem with the original spec. I did have a viton tip float valve however, there was a gas station in the area that got a load of E-85 by mistake I had filled up and when I got home the Carb leaked until I shut the gas off Viton tip was AWOL when I took the Carb apart.
Thanks G.R., that lousy gas is what concerns me with the Viton tipped valve. I'm leaning towards an original spec valve, even if I have to polish it a bit and lap it in. It seems like it would be more reliable in the long run.
I try to use the steel ones as opposed to the viton tipped needles in NH's and other carbs where they are available. I buy them from Langs. The Holley G tips seem to be fine although I give every one a good smack before I install it to form the seat to the needle. The NH ones used to be perfect but the last couple batches of them I've had to work on the needle to get them to seal. I don't know if I have a camera that will take a good photo of the tips but they vary in quality quite a bit. I work the tip with an oil stone in my Unimat lathe and then give it a good whack in the seat and install it in a little fixture I made about 3 inches long so I can suck on it and see if it will hold. If I can get it to hold in the fixture I install it in the body and do the test again.
Seems like a lot of fooling around when you should be able to just install the set and not worry about it. I don't know who is making them but I know where I'm buying them.
By the way Steve, I've never had any luck lapping them in. The only way I've ever been able to get them to hold is to get the tip smooth and them give them a good whack with a lbbfh*. Not just a little tap. I give them a good whack. I also have had to ream the hole in the seat out and whack the needle again to get a good seal. I get pretty disgusted after I buy a couple hundred bucks worth of needle and seat sets and have to work on them to get them to work. I save every one I remove from old carbs that looks like I might be able to marry up a set and get it to work instead of spending ten or fifteen bucks on new ones that I still have to work on.
Here is another gripe about the new ones. The Holley G seat thread is 7/16s - 32. I had to buy a tap and die set in that size to get the seats to thread in like they should. The seat boss is my problem but the seat itself should be threaded with a good die so the threads are sharp and the correct depth. I have a special tool to remove and replace the seats and like them to screw in easily and tighten correctly. I run the tap in the thread boss and run the die on every seat just to make sure it will do that. The two I installed last night were right but I've had some others that would not screw in until I ran the die down the threads.
*little bitty big fella hammer
There was a discussion on these about a year ago. They apparently leaked when new too, as they had a seating tool available for seating the float valve to the seat. As I recall, this is posted in a service bulletin somewhere in the early '20s.
Stan - thanks for chiming in, I really appreciate hearing your experience and tips. I just ordered one from Lang's. I have a small lathe, I'll follow your advice about stoning the tip and the LBBFH treatment. I don't have a reamer that small, but will see what I can do.
Larry - thanks, I'll go back and see if I can find that thread.
These are right out of new packages, got them less than a month ago. The first two needles are NH, the last one is right out of a new package of Holley G to the tune of fifteen bucks a set.
This is why they don't work right out of the package. They are being cut with at lathe bit instead of ground with coolant and a super fine stone.
The last pics show the threads on one of the NH seats right out of the package.
I dunno what happened, pic three was supposed to be pic five. Lest you think, whatever you want to think, I'm not. Here is the package it came out of and the other packages in the background.
Stan - thanks for posting these great photos. I see what you mean. My order is in to Lang's, so I'll see what they look like when they arrive. I imagine they will be the same. It's too bad they didn't spend a little more to have them ground. I'd gladly pay a little more for it.
You might try lapping them in with toothpaste. I have never had to try that technique with a Model T carb, but I have done it to several antique outboard carbs and it works well. Toothpaste is a mild, fine abrasive so it won't gouge the metal. Just make sure to clean it all out of there when you're done.
You'd spend a lot of time lapping these. They are ROUGH! I have a set up that it doesn't take me long to true them and grind them smooth it just gripes me that they are so poorly made and that I have to spend my time fixing something that should be good from the vendors.
Stan, I understand the frustration. I personally am glad there is anything available. At Ford-N-More we sell the new steel needle brass seat float valve. I have sold/installed many and every single one, from day one has needed to be seated. The time it takes to fix the valve assembly can be done faster than it takes me to write this post. We've been selling the the viton valve for 20 years. It is a fine valve but the fuel orifice is much smaller than the original size. Down side to this is on any T 1909-1925 50mph is the top speed, any faster the seat doesn't flow enough fuel. The 26-7 cars can overcome this because they have more head.
Well, Mike, if you're happy somebody is making crappy quality parts I guess that's your deal but it isn't mine. There are still millions of steel needles made everyday and I can't believe there isn't somebody out there who can make a steel needle with a ground tip for an NH so it doesn't have to be redone.
Either you type really slow or you have some way or fixing the tip that I haven't figured out. Smacking a rough tip with a hammer only works until there is a little wear, then it will start to leak.
My experience is that when the new steel needles came out they were much better quality than they are now. None are as good as the originals, which had a couple different designs but the better ones had a hardened tip on a softer shank. I assume those were Ford but they may have been aftermarket.
I can still buy ground tipped needles for a lot of different carbs that I can't imagine sell anywhere near the volume NH needles do. Maybe this is an opportunity for Ford N More to make a correct one that works right out of the package.
Stan- To help you seat the needle: I clamp the needle in the 3 jaw lathe, then take a fine file and run it across the tip of the needle (I also do this on original needles when I recon them) I then polish the tip with some fine sand paper 400 grit. the final step is the icing on the cake. I use "time saver" yellow 40N coarse. I hold the seat in my fingers and drive the needle with a handle held drill. (To drive the needle I clamp a piece of 1/4" x 1" vacuum tubing in the drill chuck then place the needle in the tubing.) I slather the needle in yellow compound and let it spin in the seat at high speed, a couple dips in the compound and the needle seats! Super easy and very quick. Hope this helps you out.
That's about the way I used to do it. I now have a setup to grind the surface of the tip smooth. Not to disparage the way you are doing it but there are a couple concerns with doing it that way. First is holding the angle even all the way across the tip so it will wear evenly for long life and second is that lapping it with timesaver will widen the seat. The narrower the seat the less pressure it takes to make a tight seal between the seat and the needle. I find it better to get the tip of the needle smooth enough so it will seal and then form the seat with a tap of a little bitty big fella hammer. LBBFH =)
I don't do many NH's so it isn't a big deal to do the tips but it gripes me to pay ten bucks apiece for something that is crap.
Shouldn't have to do anything to them. I am paying for a product that is advertised as being a quality product made in USA. They may be US made but the quality isn't all that good. If I could find some good Taiwan ones I would use them.
I appreciate both of you sharing your experiences. It is a shame that these extra steps are necessary to make the valves useable.
Stan - is there any reason not to use an arbor press to seat the needle, rather than the LBBFH? It seems like the amount of force applied could be better regulated this way. It also let's you feel the pressure applied. By description alone, it's pretty hard to tell how much pressure is being applied by the LBBFH technique.
Probably could but I've been smacking them with a lbbfh for about 60 years now and it's just a whole lot easier for me. It actually doesn't take much of a tap on the needle to form the seat if they are made of soft brass as they should be. Some of the seats are made from some kind of cheap crap brass that takes a bigger smack.
My point is that there were several hundred million cars built that had a mechanical carburetor with a steel needle in a brass seat. The carb was assembled and the seat didn't leak. You could, and can, buy a replacement that could be installed and it didn't leak. Why can't somebody made a needle and seat for an NH that doesn't leak ?? They make them for all sorts of other carbs. It's because nobody wants to and most people buying them won't say anything to the manufacturers or vendors about their quality and just accept junk at high prices. I just bought another couple hundred bucks of these made in USA sets and they leak unless I work on them. If I could find someplace to buy decent needles I would make the seats myself. They are not hard to make and I have the tools to do it. I make quite a few anyway for oddball carbs. I don't have time or energy to make them to sell but I'd make some for myself.
Well, I'm tired of carburetors for today, I'm shutting down and taking the rest of the day off. Saturday night isn't as much fun as it used to be but I'm going to go eat a steak somewhere and see if I can find some Country Music and some cowgirl to dance with without going to the Senior Citizens Center. I'm not that old yet.
My order from Lang's arrived today - minus the original style float valve, out of stock. Grrr... next time I'll call rather than order online. I'll call around to other vendors and see who has them in stock. I may just order a Viton tipped valve also, they are cheap enough. That way if I can't get the original style to seal, I can fall back to the other one.
Chaffins probably have them.
I finally got a new original spec float valve. The needle looked just like the one Stan posted; lathe turned, not ground. I put the needle in my lathe using a collet and smoothed it up using a couple different Arkansas stones until I got a nice smooth surface. After cleaning the needle and seat, I set them in an arbor press, and gently pressed the needle into the seat to get a good fit. Now it seals fine and holds a vacuum. So I think it will be ok. But I also bought a Viton tipped set to keep as a back up, just in case.
If the viton tipped needles don't come with a little "hairpin clippy thingy" that connects the needle to the float lever I wouldn't hold my breath on that working either.
They'll shut off the gas for sure but have a nasty tendency to stick in the seat if not physically pulled off.
What Craig said. I recently went digging though a box of old parts and found an original style needle to replace the Viton version for that reason.
Just took apart a rebuilt to check before putting on the T. This one was used by me for awhile, then stored. Cleaned.
But when checking, the float dropped, but the needle stuck. Had to use a needle nose pliers to pull out this Viton tipped one.
Looking close I could see the plastic had 'set' in the tiny machined lines of the seat, thereby the plastic Vitron was 'adhered' to the seat, causing it to be stuck fast.
Poor picture, but maybe you can see the upper most circular line around the black tip, there were about 3 or so of those circular lines, which likely matched machine lines in the brass seat. I think steel on brass, if surface finishes are very good, is better than plastic on brass.
Going to order a steel float needle for replacing this one.
Yup. If there were quality steel tipped ones that were usable right out of the bag. At one time, and I'm not sure if these were the Ford made ones or a part made by somebody else for Holley NH's, there was a needle made with a hardened and ground tip that had been added to the softer steel triangle piece. Those were the best. I had several NOS ones of those that I hoarded for a long time and finally used them. The problem with the new ones appears to me to be that they are machined from a piece of round stock on a CNC lathe and the tip is just as cut with the bit, it is not ground as it should be. They are pretty soft, too. I don't think they are being hardened at all. I'd like to set up a little system to regrind all the old ones I could find but I do very few NH's so have just been regrinding the $15 ones from the vendors that are supposed to be so great but leak like a sieve. I just do them by hand on a little lathe with an oil stone.
The new gas and all the chemicals in it is dissolving a lot of tips. I had some that would turn to mush in two or three minutes soaking in California gas.
In my experience, the weight of the float is not enough to pull open a needle that is stuck a lot of times, even with the little wire clip on it. I do quite a few conversions for 4 and 5 ball Kingstons and make a system that pulls the needle open as opposed to the ones that most restorers use that rely on the fuel pressure to push the needle up and allow flow. It's hard to get the right compromise between a float weight that will close the needle tight and one that will pull the needle open.
I've seen a lot of 4 and 5 ball conversions that were done with a Tecumseh lawn mower engine needle and seat that was J B welded into the original seat. Fortunately, they are easy to drill out and replace. Very little fuel flow and a rubber tip on the needle.
My float making project is dragging on. The guy who is supposed to be making them for me has so much business with the floats he is already making he isn't much interested and doesn't have time to make Model T carburetor floats.
Glad I followed Stan's tip about stoning the tip in a lathe. It only took a few minutes to do. Then firmly, but lightly pressing the needle onto the seat in an arbor press worked great. With the carb assembled and upside down, I can suck on the fuel inlet, stick my tongue over it and it will hold the vacuum just fine. I then flip it right side up and the needle unseats and I can blow through it. So I think it will work fine. Just waiting for it to warm up to flush the tank and line, then reinstall it.
Another problem with the needle and seat sets is that the seat appears to be made of the new Chinese brass that is all over the suppliers. Brass used to be soft for applications like seats, small rods, etc. It was pliable and malleable. I have a set of horse shoeing tongs that I cut flats on years ago to form the little flats on the end of the brass pins used to hold the weights in the needle setup in Stromberg and most other carbs of the era. Old brass would flatten out under the pressure and make a nice little end to keep it from falling out of the holes. The new brass is so brittle that pressing it to flatten the ends just shears it off. It is not Spec 360 - free machining brass - as it should be. I think the seats - at least the last ones I got - are also being made from this brittle brass which is harder to form a seat in.
The new brass also is not pliable. If you try to put a bend in it it will just snap off.
Frustrating. The seats really aren't all that hard to machine, I buy brass from a couple places that still sell American made brass rod in the correct sizes (not "close enough" metric) that cuts like butter on the lathe, threads as it should and is easy to form a seat in. Think: U & J carburetor seats, Kingston letter series carbs, oddball carbs, etc. I also have several boxes of old seats and needles from the 30's to 50's and can usually find one made of that old soft brass that can be made to fit. I have all sorts of odd thread taps and dies to match the odd threads used by a lot of the carb manufacturers years ago. I did run in to one the other day I didn't have. 7/16 x 27. I have 7/16 x 18, 7/16 x 20, 7/16 x 24 and 7/16 x 32 but not 7/16 x 27. Waiting for the set to come from England then will finish making the seat and finishing the carb.
Off to the shop, working today while you guys are watching football. Trying to get a couple U & J's on the road to new owners. Took a few hours off last night and went to the Montana Public Radio Anniversary party when I at least got my name read for being part or MTPR for 20 years as a program host. I am now about the 5th or 6th longest term host still producing programs. I had people come up to me last night and say, "I've been listening to you since I was just a little kid." =)
So what does a guy like me who doesn't have a lathe or any fancy machining equipment do to clean up the tip and get a good seal?
I've had poor results with all 3 types of valves available for the NH.
Put it in a drill and run it against a sharpening stone, then emery cloth.
Derek - if you have a drill press that runs concentric, you can chuck it and hold a good flat white arkansas stone on it with some water or light oil. Just keep the stone flat against the tip surface. Some 2000 grit sandpaper wrapped around a hard flat tool like a small file should work too.
BTW- another thing I spent a bit of time on was making sure the float arm pressed straight down on the needle. I had removed a ball valve and the lever was way off.
Stan, watch that tap set from England, it may be Whitworth or BSF (British Standard Fine) threads, which are 55º threads, not 60º like UNC and UNF are.
Thanks Ken, I've bought a bunch of taps and dies from them, they always specify if they are UNF or BSF. In many sizes they have several different thread profiles.