For some reason I have found I really enjoy rebuilding carburetors of the T era. I have an ongoing experiment where I rebuild and run different carbs on my T. So far I've run several swayback NH (stock and modified), several straight through NH, Stromberg LF, Stromberg OF, and now a Holley G. Have several non T carbs from the teens I'd like to try such as a Carter straight through that seems about the right size.
What a sweet, well mannered model T carburetor is the Holley G. The top end is lower and takes longer to arrive but for just driving low and slow like most of us do, the G is like an old pair of gloves that fits just right. I'm kinda in love with it. As many of you know it really has no bad habits. It starts well, runs well, idles well. Not a great choice for max speed on a go fast car, but what a great carb for regular T driving.
Now I want to experiment with different degrees of opening the center diameter of the strangling tube. I assume one would rather quickly run into diminishing returns due to all the other restrictions built into the casting. Anyone else been down that road please share and comment?
The best of all T carbs as supplied by the factory. Expensive to make, accurate assembly a must, separate venturi, separate idle tube -- all cost money and took machining time.
I don't think you will gain anything by changing the strangling tube but you might. Let us know.
I sure will, but it will only be a seat of the pants thing, not hard scientific data unfortunately.
Erich, For awhile I had an NH swayback on my 16 Touring when the motor was newly reconditioned. I had discarded the brass Holley as I needed to fit up a new line and put a tap on. I have since refitted the Holley and to my delight I have a perfect routine sorted where it just about starts on compression every time. It idles nice and smooth and I am also in praise of the Holley G!
I'm glad to see this. I have both kinds of G's, and will have to rebuild one and try it.
I, too have found the Holley G is my favorite carburetor for my stem-winders. With the large puddle it seems to be the carburetor that results in the easiest starting, which is important if you have an Armstrong starter.
It is not the best for top end speed, however it is also a very quiet carburetor. A Holley NH always has a sucking air "whooshing" sound to it.
Your mileage may vary.
: ^ )
I rebuilt a Holley G and put it on my car just before the trip to Richmond for the Centennial. It worked flawlessly for the entire trip, which totaled 1.800 miles. I have driven G's for several thousand miles over the years.
They make for an easy-starting stemwinder, as Keith mentioned. Also, their starting procedure is very predictable once you learn it, which is important when hand cranking. It's a very good all-around carb, IMO.
I have taken several Gs apart and, of course, found parts damaged from previous work. I save everything and put together the best of what matches. I also look at what it would take to make some of the parts. I have just about worked out a way to make the copper pickup tube for idle fuel. The learning curve resulted in several gnarled copper straws that hardly make a useful swizzle stick.
This tube and the part it threads onto are the most frequently buggered bits I've found. I can make both of these, but the little birdbath inlet nozzle is not so easy to make new or fix once one has converted it into a two piece sub-assembly.
I won't mention the casting I ruined while trying to remove a corroded bowl nut. There were a vise and cheater bar involved. Oh the lessons I learn while creating or destroying......
I hate to take the G off my car now. I plan to swap out the strangling tube for a modified version and try that experiment.
I do want to try out a newly rebuilt straight through NH though. Who knows, maybe the G will end up being the long term choice. After all, driving the T at max speed is not what I like about driving the T anyhow (LORD knows the brakes are not a high speed proposition).
Here are a couple Holley G's I just redid. The went to Argentina. If you are rebuilding G's here are a couple things to watch for.
I never reuse the venturi "strangling tube" again, I replace it with the new ones that are available. Getting the old one out can be a challenge if you want to reuse it. If you do, remove the snap ring that holds it in and make a little tool that will slip in from the choke end and get down under the bottom edge -- you can probably pop it out and reuse it.
Remove the jet in the bottom below the venturi. There is often a bunch of crud in there and it needs to be cleaned. Make sure the mating surfaces are clean. Nearly every one of the repair kits available has a phony little paper gasket in there. About 50/75/90 % of them will squeeze out of the mating surface and not seal. Make sure yours fits and if you have access to hard fiber gaskets that size use that instead. Or use a copper gasket instead. If you can't adjust the mixture after you put it back on the engine, that gasket is most likely the problem.
Make sure the needle is straight and actually hitting the hole in the jet. Even a very slight bend in the rod will cause it to miss the hole.
Check the mating surfaces where the cover goes on. An air leak there will make it hard to get it to idle and hard to start.
Often the cover is bent and the body is warped enough that those surfaces have to re re-machined to fit.
If you want to do a snakey mod, you can make an idle mixture adjustment where the cap goes over the supply from the copper tube. Add a needle there and you can adjust the idle mix perfectly. As it is the only idle adjustment that can be made is with the main adjuster.
This is one I have in now for rebuild. It's a nice one except for the adjuster rod being gone. I'll make a new one anyway.
Oh darn it now Erick! I will have to go put that 1919 G through the rebuild and try it. Or not! I have had several G's pass through my hands but have never done a rebuild and tried one on my car. My back up Kingston L4 starts easy stem winding but as with your G, not much for quickness. Right now I am running the Marvel, not as easy to stem start but has a decent top end.
By the way, Erich, Carter made an accessory carb for T's. I have one in my collection. They are pretty rare.
The Holley G is the lowest flowing carb of all the models. It makes sense it would work well at the low end. It's giving all it can.
You'd be better off running a Briggs carb.
Flow is only one measure of a carburetor and how it will perform. Flow is easy to get. All carburetors are a compromise, etc., etc., etc., etc. Holley G's start well and perform well on stock Model T's. There are many other carburetors that will perform better at higher speeds, etc., etc., etc., etc.
Stan, the carter I have looks just like that but it isn't made for a T. I can make it work, but it isn't the T specific model.
On the Carter you show, how is the mixture adjusted? Mine has needle valve on the side (like the photo above) that seems to be only for idle mixture. Seems the main mixture is controlled by the size of the orifice in the jet?
Interesting how the idle fuel passes through a variable orifice built into the butterfly shaft.
Do I recall a very recent article on T carb performance testing in one of the club magazines that showed the G not in last place, but the L4?
Mark, follow Keith and I (and others) and drink the G kool-aid. At least just to know how you like it. Easy to swap out if you don't fall in love.
Stan, I am always glad to soak up your time tested experience. Thanks again.
Let me clarify, it took slightly longer to get there, but it still let me hit 44 mph. Other carbs let me get up to 50 plus if all is perfect. The G is not a real limiter of T performance for regular T driving.
I have no doubt some (not all) other model T carbs top out at a higher max flow rate, but the G flow seems plenty high enough for day in day out driving.
What kind of carb is this? It's been laying around here for ages, and if it's any good I'll use it on the Speedster that I plan on building
Hal, that is the common Holley G in cast iron, I think the most commonly found. I will say up front, I'm no expert, but, looks like a bit later in the G production run due to the long throttle arm and the double choke arm, indicating it was for an electric starter car.
Hal, it would be a fine candidate for rebuilding. It is missing a few parts, but they shouldn't be to hard to scrounge up.
On second glance, it looks to have been built up from several vintages of G parts (brass and iron)?
It a Holley G, the carb under discussion. It's a combination. It has the cast iron body introduced about 1919, and the earlier bronze top plate and throttle lever. A later version of the ones Stan posted above. Looks like it has the double choke lever for use on electric start cars.
I appreciate the input, Thanks
Holley G pics.... just some pics from G restoration.
Works of art!!!
The talent displayed here amazes me. If I were to try to rebuild a carburetor I would need a peck basket to keep all the left over parts in.
I think I'll just continue to send my carburetors out to you experts.
Notice the difference in top plates between Hal's picture and Stan's? I'm not taking the time to look it up, but the presence or absence of DETROIT helps in dating what you have.
One cover has the patent date of Dec 22, 1914 the other has patents pending.
I just rebuilt a holley g carb and was basing it on what i had taken apart. it did not have the copper tube that everyone is mentioning above (low speed/idle and venturi) I need more info or am I better off just ordering a rebuilt one and start all over again. Always hard working on others trials prior to mine!! Any thoughts would be greatly appreciated.
OH GOODIE! Pictures, just what I've always wanted...thanks Stan!
Now how about a spread on the Stromberg OF?
Hi Erich, not sure if you got my telephone message on Friday, but the Carb parts arrived. I can drop them off if you like, just give me a call, when you have time.
My 15 touring had an NH on it when I bought it but it came with either a Brass G or Kingston. I bought one of each just to have with the car so it's correct. In any event, several years ago, I decided to rebuild the Holley G and give it a try simply because it is so cool looking. I did have to lap the needle and seat to make them seal well and I also had to make the brass nozzle that the tube screws to and install a modern float.
I was blown away by the performance. The carb is very quiet compared to the NH and provides tremendous low-end torque. That low end power is what I need living here in the West Virginia Mountains. I found the G to out-perform the NH when climbing the hills here.
I found the same to be true with the Holley S (2-screw).
Agree with you. I have one on the 1914 runabout and it runs great and is easy to start. The 1914 gives me more free starts( about every time when I prime it)as the 1922 woody and the 1926 touring.
Just have a question. How do you take out the mean spray??? The float seat is the same problem.
I tried about everything I could read on this forum.
have a fine sunny day
Andre (with horrible spine pain)
What do you mean by the "mean spray"? If you are referring to the brass nozzle that the copper tube is screwed too, I usually grab it from inside the throttle body with needle-type vice grips and backing it through the opening. Sometimes I've had to clamp the carb in a vice and get at it with the grips on the inside and the screwdriver from the outside and turn in unison. It buggers it up but I replace them anyway. I remove the seat by machining a slot in it that allows me to get a fat screw driver in there and turn it out.
I was talking about the main spray. must be the pain killer.
The idle jet just screws out of the threaded hole it is in. To remove the main jet it helps to have a tool that keeps the tool centered in the carb but having the end turned to just fit in the dip in the jet. It also helps to have a washer that slips over the tool and centers it in the body. Very easy to make. Also, the jet is not the same in the early and later versions of the carb. If you are replacing it with another make sure it is exactly the same.
The original gasket between the jet and body was a thin lead or copper gasket. The ones supplied in the gasket sets are paper and will squish out of where they are supposed to be, allowing gas to be drawn around the jet and the G won't run. I use a hard fiber gasket in there instead of the crap supplied in the kits.
Stan, how do yo clean the carbs? They look great.
Bead blast with ultra fine bead, two ultrasonic cleaning baths, wire brush with .006 stainless steel wire wheel -- yup, the ones that are $65 each -- powder coat and 800 grit whisker sanding drums and several buffing/polishing wheels. As well as three lathes, two mills,5 drill presses, etc. I also have about 25 or 30 shop made grinding setups for cleaning and straightening the seats so the gaskets will hold when tightened.
Got a great package in the mail the other day. Leonard Evansic from Pennsylvania sent me some of the tools he had made for working on Holley G's. Very well thought out and well made. How nice is that!!!! I put the seat tool to use over the weekend. Worked perfectly.