Carburetor Rebuilding, where did I get this?

[Ben Umberger]

I routinely capture information on given topics and nicely put it in proper folders for later recall. As I was looking through my carburetor folder I found the text below. I suspect I got this from the forum but I don't really know. I would love to know who wrote it, there are some details I haven't seen before. It is clear to me that I don't have the entire test but would love to have it.

BTW what does it mean to "Peg out the holes" (end of page 2)

Thanks to the guy who wrote this and thanks to whoever helps me find the full text

Ben L. Umberger


The test follows:

Carburetor
(Possible)Identification: A is 1" throat, B is 1 1/4", and I believe BB is 1 3/8".

Sounds like a '26-'27 choke rod. They are square and slide in a socket that is the top half of a U joint on the carb needle. The hole is for a pin that holds a small collar with a tap on it. The tab has a hole in it and the choke rod (wire) runs from this hole down to the choke lever. So when you pill up on the choke rod it slips in the top portion of the U joint, but the pin lifts the collar, and choke wire pulling the choke closed. At least it does on my '26.

Unless you're restoring for concours, hang the NH on the wall and get a better carb. As well as newer carbs, almost any aftermarket carb. from the era will provide better fuel mix than an NH. That includes the Schebler FA and Stromberg OF, which by the F means they were built for the T.

Someone said that you could replace the cork float in the Holley G with a John Deere Brass float. JD P/N is 93004/AR-10066R. You have to unsolder the JD tab and put the Holly G tab on it. I think the float is the one used on John Deere ca. 1939 on the Model D. I priced one once and it was pretty spendy, I think in the neighborhood of $40.00
Overhaul
I would take the carb. off and remove the float, and both needles, blow every thing out with air. At the back of the carb. at the flange there is a 1/8" brass plug. Drill the plug out follow the passage down the carb. towards the venturi about 2" is another 1/8" plug that is on the outside of the carb. Drill this plug out also. Now follow that passage down to the venture tube about an inch or so and you will find another brass plug on the side of the venture tube drill this plug out also. These three passages are always blocked. Use air to clean them out. Now take a white coat hanger from your wife’s closet and run it in all three passages. You should be able to see the end of the wire go through all three passages. Now its very important that you locate two very small holes on either side of the butterfly that is on the flange end of the carb. These two holes are about 5/64", take a wire or a 5/64" drill bit and make sure that these two holes are clear. They go into the 1/8" hole that you drilled out earlier. Now go to a hardware store and get some brass welding rod and sharpen the end and cut three plugs to put back into the carb. before you put the flange plug back in take your WD 40 and place the little red tube in the rear of the hole and see if you can spray it through the carb ;and out the bottom of the venture tube. If it is going through OK, plug the flange hole. Next make sure that your venture tube is clear. I always take the valve seat out of the venture tube and run a wire and air up the intake air passage under the name tag. Use you white wire its easier to see. Next make sure again with your white wire that the over flow passage is clear. Your float can't work if its not clear. This passage is located about 1/4" from the rear of the name tag. If you have not done so in the past you may want to bead blast the entire inside to the carb. before you do the above steps. Dave Huson

I have found that the spray on paint remover found in paint or hardware stores will cut old gas varnish fairly quickly. This is the strong stuff that burns if you do not have rubber gloves on.
Carb Float Fix
Many mechanics have been conditioned to ask for a float each time they rebuild a carburetor, due to the reasonable price of modern, mass-produced floats, and the propensity of nitrophyl (foam) floats to absorb gasoline after time. In dealing with older, NON-CURRENT-PRODUCTION brass floats, neither of the above are true, and a mechanic should attempt to 'save' the float if at all possible.
The first step is to clean the float and inspect it for obvious damage. Small dings and dents are quite common, even in unused floats, and occurred when the manufacturer shipped the floats in bulk. Major dents (generally caused by water freezing in the carburetor) are not generally repairable. If one can hear liquid sloshing around inside the float, skip to the next paragraph. If the float looks to be reasonably damage-free, it should be tested. Testing is accomplished by grasping the float arm with a pair of needle-nose pliers, and submerging the float in very hot water. The hot water will pressurize the air inside the float, and a leaky float will blow a stream of bubbles.
If the float should need repair, it is important to understand how the float was originally produced. Virtually all brass float pontoons (the floating part) are composed of two pieces (a few are more) of brass soldered together. The pieces differ in the seam area, as one piece has a male seam and the other a female seam. One float piece will also have a small hole for temperature equalization. This hole will be covered by a small drop of solder, and will be as far from the seam as possible. The manufacturer would solder the two pieces together, allow the float to cool completely, AND THEN close the equalization hole. Soldering MUST be done using a soldering 'iron'. Repair should not be attempted using either a torch, or a soldering gun. If you plan on disregarding this advice, read the next paragraph first! The following procedure works for us (no, we will not repair your float unless we restore the entire carburetor): First, if liquid is present inside the float, find the hole, and remove the liquid by placing the hole down inside the hot water. The pressure will force the liquid from the float. If the float has much liquid, it may be necessary to remove the float from the hot water, allow the float to cool, and repeat the hot water dip. Once the liquid has been removed, and the leak has been marked, open the equalization hole by removing the solder. Solder the leak closed using as little solder as possible. A small piece of tape over the equalization hole will allow the hot water test to be preformed. If there are no leaks, remove the tape, and ALLOW THE FLOAT TO COOL COMPLETELY before closing the equalization hole. A final test, and you have 'saved' a valuable float.

There is usually a small pinhole somewhere else, not near the seam. First, make sure the solder is off the hole, then do the seam, and when it's cool, then solder the hole shut. Trick here is to keep the solder flowing onto the hole sight while the air cools off, then it sucks the solder into the hole instead of out of it. David D.

Level
The MTFCA carb. manual does not list a setting for the H-1 that I can find. On most T carbs I have worked on...with the float at the top of its travel...the top of the float is parallel with the flat surface of the carb body directly above it. In other words the gap between the top of the float and the bottom of the carb body is equal all the way across. Michael

Leaking Needle Valves
A new method to fix a seeping float valve: By Reid Welch.
Your carb probably drips. My carbs used to drip. Almost everybody's carb drips until the float valve is upgraded to a modern neoprene tipped valve. But you may not need to go to such extremes as to spend a dime. For the nearly sure-cure, go to a Chinese restaurant and have a good meal. Bring home a chopstick. What? Yes, a chopstick. You are going to improve your float valve- maybe even make it dripless, with a chopstick. Before proceeding further let me say this is my own technique. Have read every old book in sight and you know the standard line: "grind in a leaky valve" (please, don't try that) or "Hold valve in seat and tap with a small hammer" (never worked for me yet) Here's the problem: These steel tipped, brass seat valves did not leak drip when they were new. The steel cone is actually a type of early stainless steel, Monel metal to resist corrosion. Even though the brass seat is considerably softer it is generally the case that the steel valve shows some wear. Maybe very considerable wear.
What do you do about that? Nothing- only as a last resort would you reshape the valve because the necessary precision requires a good lathe. The valve has to be perfectly round or it can never seal. Even when worn looking the valve may remain perfectly round; it just has become broader contact area on the seat. This is of no advantage, but it's not a fatal flaw either. Years of "yammering" around on the brass seat has polished away much Monel metal, but in so doing the valve probably rotates too. And if it rotates as it yammers it will remain very round. Obviously, we cannot seal a round hole against a fluid so penetrating as gasoline unless the plug is round too. Or made of Viton rubber. But WE are men, and WE like to make things work despite age and decrepitude. The carb's, that is. We do that, and save five bucks on an NH Viton valve. And can live easier with non-NH carbs for which no new float valve is available. It's been frustrating forever- We've turned and trued steel valves and polished the Monel to perfection. Result: carb still dripped. What next to try? The seat. I've tried "grinding" the newly trued valve into the seat, using Simichrome polish and then clean oil. Still dripped.
If the float valve is round, and IF the float valve is getting a square push from the float then leakage owes to some invisible defect in the brass seat.

In clock work(another hobby), steel pivots run in brass bushed plates. When cleaning a clock, the most important aspect of the cleaning is to "peg out the holes" with a sharpened orangewood stick. Orangewood whittles to a very fine, sharp, tough point for pegging such tiny holes as are found in watch plates. We peg and re-peg, twirling the stick in the brass hole until no more stain comes off on the stick. Only then is the hole clean of wear products and dirt. Now a float valve seat is not a clock bushing but in a way it has a much rougher life than a clock bushing- We are going to peg the old brass seat out with a chopstick. And the seepage will almost surely be eliminated. Why?? The float valve continuously pounds and vibrates into the soft seat. Fuel contains tiny bits of solid dirt. Dirt gets worked into the seat. BUT the real culprit is the brass itself. When brass is pounded over and over, what happens?- it spalls and develops tiny fractures. A layer of microscopically rough dead brass resides on the seating surface of the valve. This layer is not only rough, but it is porous. THIS is the #1 reason why otherwise perfect float valves allow the carb and you to suffer with "wet nose" syndrome.
Sharpen the chopstick as needed. Twirl the dry chopstick firmly, by hand, in the float valve seat. Examine the tip of the stick- it became black. Scrape off the stick and twirl again a few times. Scrape off the dirt. Continue doing this "pegging out" until the stick comes out clean. Use magnifying glasses if you need to because you must know the stick is coming out clean- it's rubbing surface merely becoming burnished by the pressure. Now oil the tip of the stick and twirl a couple more times. Done.
Examine the float tip under a strong lens. Normal appearance should be bright and shiny, exp. where the seating occurs. It does not matter if long wear has necked the seating area so long as it has a polish. You might as well polish the tip by hand, or better yet- polish it with gentle rouge on the buffing wheel. Wipe it clean, and "peg" its tip into some soft end-grain wood. Insert the dry float valve, turn carb upside down and do the Suction Test (see MTFCA carb rebuild book. If nothing else is wrong your valve will hold tongue suction until the cows come home, or your tongue gets a hickey. You will not have a carb drip again for a very, very long time- But DO use an in-line pleated paper fuel filter.
Remember- this drippy carb syndrome can be caused by simple dirt pounding into the brass seat. BUT the other endemic cause of leakage has never been addressed before this posting: the "dead" brass surface on the seat. The chopstick removes both the micro-dirt and all the dead brass. IF the carb still seeps, check that the seat has it's fiber seal washer intact and sealing, and the body or fuel elbow is not cracked or defective. (talcum powder helps find tiny leaks). Per old advice read in the club magazine, seal the bowl to the underside of the casting with #1 Permatex sealant. You can remove the Permatex later with alcohol. So will today's fuel tend somewhat to remove Permatex or about anything else short of epoxy. IF a drip remains, and the valve passed the suck test, Look at float condition, float height, and alignment of the float's pusher on the valve- IF the valve fails the suck test (it should be perfectly tight, holding suction indefinitely), be sure the fuel union is not cracked. Be sure the seat is bedded on a good fiber washer. If the suck test still fails the valve tip is out of round OR the seat is out of round. Pegging will not true up the seat. Truing a brass seat is easy- if you have an appropriate size, preferably new, steel bearing ball. Tapping the ball into the seat will can make a band of contact that is very round indeed. The ball must be of a size that will leave a ring that the float valve will seat upon. That is, the ball can't be too small or too big. Don't use an old, rusty, used up bearing ball. Get a nice new one out of some cheap new bearing. Drop the ball onto the brass seat. Use a short wooden dowel punch and a small hammer and give some sharp raps around on the top of the ball. Examine your work with the strongest lens available. Or go see a jeweler and have him look at the seat for continuity. Then repeat the pegging process again. You will find by the new "dirt" on the stick that smacking has re-spalled the brass. Pegging cleans out the fractured metal. Finish with as before, with a final pegging with the stick oiled.
If the new seat corresponds with a round, undamaged portion of the float valve the suction test will be perfect. If the seat corresponds but the test fails, then the float valve is indeed out of round. DO not try to "grind" in the float valve. It has become a small job. Unless you have a good, precision lathe, give the valve to a friend who has a lathe and a talent for detail. If you saw the very worn float valve on my Xenith you'd expect it to leak. But I did not even have to touch it beyond polishing the tip and pegging out the seat. There are no drips on the floor and no gas smell in the garage. And DO use a good inline filter! Reid

Holley NH that caused engine overheating. I found that the brass nut on the top of the carb. was cracked, the one that keep the needle from backing out. So much excess air was being sucked through the top of the carb. that the previous owner had to open the needle 3 turns to get the T to run. The mixture was causing the T to overheat and the tail pipe to get very hot and glow. A new brass nut solved the problem. Have you checked for any intake air leaks in the carb. itself, carb to manifold, or manifold to block? Sucking in excess air could make you need to open the gas needle too much. All three of my cars run best between 1 to 1-1/4 of a turn open


END of the quoted text

[Steve Jelf]

This is by three or four writers. The first is Dave Huson. The second is "David D." (Dewey?) The third is from "Michael". The fourth is from "Reid". The last paragraph is anonymous.

[KBurket]

Part of it is from here:
https://www.antiqueautoranch.com/montan ... binfo.html
See section with heading “Leaking Needle Valves A new method to fix a seeping float valve: By Reid Welch.”

[John Codman]

What is the problem with an NH? The NH on my T runs beautifully. About four years ago I took it apart to clean it (bad fuel) and replaced the bowl gasket. Other then that, I haven't touched it in the ten years that I have owned the car.

[George Mills]

Hey Ben,

I'm going to take a wild long swing at this one. If this is a MTFCA forum clip or even a clip from the old MTFCI forum...

Dave D. most likely is Dave Dufault of New Hampshire. Not sure of Daves present status in life...but would generally say he use to be very savvy on things like carbs, of all variations.

With it being Dave (perhaps) I would then guess that REID is either Reid Welch...way back when original forum top contributor and one heck of a guy, or a guy named John Reid who was around for a while but can't say how many years ago that was.

Wouldn't spend too much time gopher holing it...but thats where I'd start!