MTFCA Forum

Are the balls in the 5 ball carb all the same weight? We have a large 5 ball on our racer and it runs rough. Not sure if it’s due to the carb, or can timing, or a combination of factors.
Thanks,
Rob

Have you seen this…

https://modeltfordfix.com/rebuilding-th ... el-t-ford/

This article doesn’t discuss the weight… but doesn’t mention the importance of it either. It fails to mention a specific size too, so may suggest they are all the same

Maybe something in one of these older post will help:
https://www.google.com/search?q=MTFCA+5 ... e&ie=UTF-8

Thanks guys. Bruce has the cab in MN. We'll go through the links and see what we learn. I think the carb is the reason for the rough running, primarily at lower engine speeds. When you pull on the throttle, it hits on all and takes off.

I've worked on a number of 5-Ball Kingstons of various sizes for tractors/cars and Royce Peterson's outstanding article in the link Kevin posted above, is the best I've ever seen on rebuilding them. One important note is that the balls need to be all the same size, the right size for the seat/cap and made of brass. I've seen several carbs where the balls were replaced with steel ball bearings which are too heavy to allow the carb to work properly. Also the ball cap position is very important for correct air flow as shown in Royce's article. Here is a link to the source I've used for the brass balls: https://www.mcmaster.com/balls/

Good luck on your project.

Although period correct for your car , is the 5 ball actually the carb that ran with that engine? Do you have any photos or documents which show a 5 ball on that engine. Perhaps if you are looking for a better low rpm idle a different more adjustable era correct carb might be the go? As proven, the 5 ball works well with open throttle, but that hot engine/cam timing etc was made to go flat out,not idle! Just my thoughts!

Thanks Roger.

Warwick, the other remaining racer, the largest, also has a 5 bal. Unfortunately, no literature or drawings I’ve found indicate any other carburetors, although it wouldn’t surprise me if they used different types.

Below, photo of the carb on the 410 c.I. racer at THF:

Thanks for the great pic of the intake and carb set up. From the pictures, that carb and manifold look custom made to suit the big engine. The 5 ball looks to be made of some kind of alloy and may be of bigger size construction all around?? The carb outlet is different to the normal 5 ball on a 1910 production car and is mated up to a custom inlet manifold. Similar to stock production but still all different and unique? Maybe a standard 5 ball is not suited to the application for low speed and RPM's. Great looking and sounding piece of Ford history. Your mates will be sure to get it sorted for you. I hope to be able to see it and maybe even ride in it one day.

A ride is always available. The carb we’re using has a 1 1/2 in. throat. A friend who has our old K touring has been running the same size carb on his K touring for a few years and it idles and performs well. This one has steel balls and one ad for the five ball has bronze balls listed. We’re going to find new balls and try to make sure the seats are fitted well.

Stan Howe mentioned that the balls have a special weight too.

https://www.mtfca.com/discus/messages/3 ... 1359018341

I was curious, so I weighed one of the brass (bronze?) balls from inside my 5 ball on a digital scale. It weighs 5 grams. I will check my other 5 ball carbs that I have to see if there is variation.

Also, they are bronze balls, not brass apparently. Of same weight. See original ad below.

The interesting bit is that there a “ various sized openings “ mentioned instead of all the ball seats being same size?

All of the seats conform to a 7/16 ball and are finished to a degree where little to no leakage can occur past the ball when completely seated. The design is elegant simplicity in that a sphere, of course, wants to seal a ring, and will do it well so long as the ball surface finish is of sufficient form and the "ring" has no occlusions.

By design, the through-holes vary such that at a given pressure differential, each ball has progressively more area exposed to high pressure, and thus more force/lift available to unseat the ball and allow more air into the mixture. The result is that the ball covering over the largest hole will lift first and the ball with the smallest hole will lift last (and only under the most extreme of pressure differentials). This allows for a variety of fuel richness through the vacuum range without having to change mixture settings through that same range. Different carburetors achieve the same thing in different ways. The Kingston is remarkably efficient for its time and design.

When they state that the "balls lift from their seat at the exact same pressure every time" does NOT mean that they all lift in unison...but that EACH will lift exactly and consistently at THEIR designed pressure differential.

Post Script: insofar as the original design was for bronze balls, replacements should take into fact the density/specific gravity of bronze vs any other replacement. Brass is a reasonable substitute, while steel or bronze/aluminum (being less dense than bronze) may play havoc with the stochiometric balance produced by the carb. Bronze/aluminum would be especially problematic, being decidedly less dense than any other material previously mentioned. Whether or not it can be noticed or much less measured would be a big question given so many other variables potentially in play.

I've found that the 5 Ball Kingston was one of the best of the early carbs of that period. They were very popular on many styles of engines including the big prairie tractors of that era and were known for their responsiveness with varying loads. When these tractors were running sawmills, they had to go from a very lite load to maximum output almost instantly and the Kingston was one of the few carbs that could give that kind of performance. Of course, they were also used on many of the cars in the early years for the same reason. Before the development of carbs with accelerator pumps, Kingstons were one of the best designs to handle the rapid demand changes of engine load. After all Henry must of liked how they performed using 5 Ball (and later 4 Ball) Kingston carburetors on Model Ts from 1908 thru 1913. I'm guessing that Rob's specially built racing engine would likely have use it too and once they get it correctly rebuilt and dialed in, he will be happy with its performance.

Remember, this is a race engine.
Cam & compression can have a big effect on the idle.

I imagine the guys working on this car know this, but here are a couple photos from the Henry Ford Museum. They show the Model T Frank Kulick raced for the Ford Motor Company from 1910 until 1913. It clearly shows the 5 Ball Kingston just like what Rob has on his car and Frank reached a speed of over 107MPH with it.

Thanks again everyone. I'll address a few things, and then add several questions. Roger, great pic of the racer at THF, with it's Kingston 5 ball. While THF called it a 1910 racer, it was actually initially developed and raced against the Blitzen Benz in in September 1911. Originally that engine (if I have the research correct, and that's always a moving target as we learn more) used was a389 c.i., and evolved over the summer of 1911 to the 410 c.i. it remains to this day. The engine is "hidden" in the T style chassis by pushing it forward into the V nosed radiator (no fan). It's so wide the outcropping on the right side of the brass radiator was needed to allow an oil filler (consider where the oil filler is on a T). The Bosch dual ignition mag was moved behind the firewall under the "lunch pail," but that wasn't done until the summer of 1912.

In early 1912, this racer made two official runs on ice (Lake St Clair), mimicking Henry Ford's record setting run years before with 999. It achieved a top speed of 109 mph. The racer beat the Blitzen Benz the fall before on the Michigan State Fairgrounds track, clocking 50 seconds from a standing start. At the time, the Blitzen Benz held the world one mile circular track record, I believe about 48.25 seconds, but FROM A FLYING START." After the timed match race, the Ford driver, Frank Kulick, offered a match race against the Benz, and Bob Burman, the Benz driver, for $5,000 (about $155,000 today). Burman replied "no, not with this racer."

Ford, with Kulick driving, also raced two other "specials" that day, this 300 c.i. (Actually 298, to make the 231 to 300 c.i. Class) and a 228 c.i. (161-230 c.i. Class) racer at the same meet, with both winning 5 mile races.

Ford and Frank Kulick did not again run in a track race, but the big racer and 228 c.i. did run in the 1912 Algonquin (near Chicago) hill climb, setting course and overall records on both hills.

Below, a photo of the racer taken at the Ford Detroit Branch store, winter of 1911-12, after the 1911 win over the Benz. The mag hasn't moved to rear of the firewall yet:


Frank Kulick seated aboard the big racer at the 1912 Algonquin Hill Climb. This is the last time the big racer would compete, setting records for both hills and the overall hill climb. THF has the trophies from all the Ford wins at Algonquin, although, like the racer, they are not on display. The mag has moved to the rear of the firewall. The outcropping is noticeable on the right side of the radiator brass for the oil filler. The frame is lowered by using a straight front crossmember and a rise toward the rear of the elongated frame. Under frame trussing like that used on several earlier Ford racers and the Model K helped hold the strain of large motor on a longer T style frame:

More questions.
“I’m about to open my mouth and remove all doubt…”

Seats measurements are .663, .638, .625, .638, .628.

The balls currently in the carb are steel, .688. Anyone have an idea what they should be?

You're describing balls as being 11/16" or so in diameter...that seems large to me. Perhaps my eyes are deceiving me, but in your picture, at least 1 ball appears larger?

If undisturbed/molested, the screw-on cap has a skirt in which the ball just fits when it lifts. This is your clue to the correct size ball.

As far as the through holes, I think someone has mucked around and wallowed out some sizes. There should be 5 different sizes of holes, and each seat has a different shape from the factory, to control the flow of air vs the amount of lift. They are not all supposed to be just a random chamfer...some are chamfers (largest hole(s)) and some resemble bowls with barely line contact with the balls at the innermost opening of the bowl (the smallest hole). Repairs through the years may have simply ground identical seats into them which all conform to the tool used (which alters the factory seat shape). When you say "seat measurements" you should be using a ball gauge or plug gages to measure the through-holes...that is the meaningful dimension.

I almost wonder if someone might have removed the seats? Do you see any evidence of threads going through where a seat would have been?

I don't have one in my shop right now to compare but am going on memory.

Scott_Conger wrote: ↑

Mon Dec 05, 2022 11:17 am

You're describing balls as being 11/16" or so in diameter...that seems large to me. Perhaps my eyes are deceiving me, but in your picture, at least 1 ball appears larger?

If undisturbed/molested, the screw-on cap has a skirt in which the ball just fits when it lifts. This is your clue to the correct size ball.

As far as the through holes, I think someone has mucked around and wallowed out some sizes. There should be 5 different sizes of holes, and each seat has a different shape from the factory, to control the flow of air vs the amount of lift. They are not all supposed to be just a random chamfer...some are chamfers (largest hole(s)) and some resemble bowls with barely line contact with the balls at the innermost opening of the bowl (the smallest hole). Repairs through the years may have simply ground identical seats into them which all conform to the tool used (which alters the factory seat shape). When you say "seat measurements" you should be using a ball gauge or plug gages to measure the through-holes...that is the meaningful dimension.

I almost wonder if someone might have removed the seats? Do you see any evidence of threads going through where a seat would have been?

I don't have one in my shop right now to compare but am going on memory.

Scott,

Does it maybe appear that with Rob's carb, all 5 seats & through-holes are the same size and that the variable here is the ball diameter/weight? The idea being that differing ball weights would lift sequentially, in the same way that equally weighted balls would lift off of differing seats/through-holes.
I realize this doesn't jive with the dimensions that Rob reports, but it does seem to agree with the photos he provided. I also realize that was not the scheme that Kingston used, (that I know of at least).

Jerry

anything is possible!

Within the understanding of the era, carburetors in general have always been extraordinarily well thought out and executed in their manufacture. The subsequent repairs? Not always so much.

In an awful lot of instances, so much butchery has occurred on less common articles through the years, short of finding original literature or the elusive NOS part, it is often easy to go down the wrong path when attempting to resuscitate these things. That may be the case here.

This is an interesting thread to read. Wouldn't the 'effective diameter' of the 5 holes be the diameter of the 'ring' where the balls contact their respective seats? That dimension determines the area of the ball that is exposed to the pressure differential that causes the ball to lift to introduce air into the fuel mixture? If the seats were resurfaced in a way that changed the diameter of the contact 'ring' or if different diameter balls were installed the function of the system would definitely be altered. Ditto for changing the ball material to a more or less dense metal as has been pointed out. It appears to me that the original design varied the seat configuration but used 5 identical balls to achieve the desired fuel mixture over a range of intake vacuum levels. I'm most interested in learning how this really works out. Best, jb

Wouldn’t the parts list offer different sized balls if they were different? I think the seats are different sizes not the balls.

Ed

you're correct...that is how it was originally designed: 5 equally sized, equally weighted, bronze balls

Thanks guys. I’ve sent this on to my friend Bruce who has the carb now. I agree, one would think there is only one correct size ball, but it looks like “after market” work may have changed things dramatically. Maybe Bruce will post his observations. I hope we can get this carb functioning properly.

From my friend who has the carb:

“Scott is correct, the center ball is 11/16", the other two are 5/8" and are in the only seats they won't fall through. The measurements are ID of the hole, showing there really isn't a graduated size in this unit. I suspect that the seats were "cleaned up" at some point and lost the factory setup. I fear that the only way to save this unit is to bore out the seats and thread in New, correctly machined seats. But we don't know what that is at this point!”

Any suggestions?

I don’t have a boat, nor need a small anchor….

Rob

at this point I'd start a new thread and request (implore!) sample sizes from owners of cars successfully running them. Once the through-hole diameters are established, then the correct seat geometries can be applied following that information.

I think you're in for some extensive work

A boat might be cheaper

Thanks Scott. I guess I was a “Captain” when I left the reserves. But that was Army…. (and I really don’t need a boat….)

A friend with my old K touring has a 5 ball that he just took off the “K.” It has the same size intake, although is a little different configuration (maybe off stationary or tractor engine). Maybe we’ll try it?

Found a replacement, or parts donor. Hopefully my "anchor" didn't just double in size.....

Money cannot buy happiness, but it can finance the illusion.

Good for you

Thanks Scott. I could use more illusions…..

Rob: Thanks for posting.

The caps appear not to be identical, (or is that an illusion?) apparently to limit the lift of each ball, some lifting more than others? Are all the ball seats identical? Thanks, jb

… —- … … —-…

I’m not sure the one we have hasn’t been altered beyond repair (at least without major corrections). The throats appear to be the same, and this one appears to be in good unaltered condition with new balls. We’ll see……

Thanks,
Rob

I do understand the concept of these carburetors and how they're supposed to work. What I do not understand, is how they're supposed to work when coupled to a vibrating engine, going down a bumpy road. I would guess that those balls have got be vibrating around, moving everywhere and doing everything but sitting on their seats, waiting for the right vacuum to lift them up. They must work well on a nice steady flow bench, but in a car???

They're heavy for their size and I'm certain that they stay seated just fine (when they're supposed to be seated). It would take a lot of energy at low frequency to cause enough lift to be meaningful to the air/fuel balance. They really are great carbs for the era and would not have lasted in production if they were faulty on rough roads.

Now, if I said that steel ball bearings would sit tight on a bumpy road would you agree?

Thursday's Factoid:
If you think they would sit tighter than factory bronze balls, you'd be wrong. Steel is less dense than bronze and thus lighter in weight per cubic inch...they are actually lighter. I cannot count the number of times people find steel balls in there and (correctly) replace them with brass because they (incorrectly) believe the steel is too heavy. One of the few instances in life where being wrong will lead to the right result.

Yes Scott, I realize they must have worked fine, despite my "concerns", or they would be non-existant today, versus just fairly hard to find.

Just had a quick look at my 5 ball, restored by Stan. Balls all measure .435", ports below all .410". Don't have a scale in my workshop but I am guessing that same size means same weight. Not sure how this chimes with the progressive response to vacuum described above. I haven't yet run this carb myself but I trust Stan's reassurance that he ran it up on his test engine.

Thanks Jem. We’re goi g with the replacement, and trying to determine what the ball size should be. While a larger carb and balls/seats, the relation between the ball and seat may be similar.

Hopefully we try it later this week.

So the balls in Rob's carb are 11/16" (0.688) and 5/8" (0.625), or is that just the size of the holes that the balls drop in to?

Jem's are 7/16" (0.435).

How many different sizes of 5 ball carburetors are there?

The Kingston Model # 4100 for Model T's had 7/16" balls and was unchanged through its end of use in the Model T. The balls lift about 1/32" when open if the seats are perfect and the caps are made correctly to properly limit lift relative to the reworked seat(s).

The Kingston Factory number for the complete carb was P/N 553

Kingston catalog # for the ball(s) was 4122, the Factory P/N for the ball(s) was 2122 and the FORD P/N for the ball(s) was T3088

The complete carb sold for $9.00

Scott (or anyone), any idea how large the holes/seats were? We’re trying to determine how large replacement balls should be, based on how far down in the seats they should fit? Also trying to determine any rhyme or reason to how the different seats were graduated?
Thank you,
Rob

The skirts on the inside of the caps should tell you your ball diameter unless they have been cut off. Even if they were, hopefully some sort of tell-tale remains of the diameter of the skirt(s). Of the 5, I'll bet you can cypher out the original ball size from one of them.