Please give me your thoughts on the grouse jet. I have been using one on my holly NH. I have been trying to narrow down a bit of a miss that sometimes turns into an awful hesitation. I've looked at the usual things . Advise is welcome
I had an early Kingston carb outfitted with a grose jet. When the gas got too low in the tank the engine would start missing and then quit. I'd still have over a gallon left in the tank. Finally figured out that the float valve was sticking slightly. Its the grose jet.With the carb off and blowing into the gas intake line, by mouth, I noticed that slight extra pressure was needed to unstick the valve. Maybe they're better now than they were. This was about 15 years ago.
Grouse jets might work fine for gas tanks in the cowl but they are reported to stick and hang up when using the under seat tank. There is not enough head pressure esp when the lank is low.
I've tried them on both kinds and don't like them. Same problem as above on both cowl and under seat tanks. They don't allow as much fuel flow. Might be OK on level ground, but not good on hills.
My experience with them is that they like to stick either open or closed with both cowl and under the seat gas tanks and cause problems. I replaced both of mine with stock valves and have not had a problem since. Just another case were modern is not necessarily better.
I had them and don't like them. In the Holley NH I like the Viton tipped float valve,
Funky gas additives out here caused the Viton valve to swell, distort, and stick. I installed one of Larry Smith's original style NH valves and not only have had no problems but better performance due to the correct 1/8" orifice.
John, I had something like that happen on my 13 hack. When I started the day on tour, the car ran fine. In the afternoon, it started to do what you describe and even worse. My problem turned out to be vapor lock with the position of the gas line (1/4 inch) too close to the tail pipe. When the afternoon came I had 1/2 tank or less and the pressure was not enough to make the gas flow through the heat. I rerouted the gas line and solved the problem. I also have a grose jet on all my cars.
No problems with a Grosse-Jet valve on a straight-thru NH..... '26 Runabout.
Almost swore to having my first valve problem today.... turned out to be carb & intake icing due to our high humidity & mid 80's temps. Really didn't want to put the hot air pipe back on a hot engine, richened mixture & put up with the chugging till it cleared itself.
One of my Model T buddies had a Grosse Jet valve on his '13 for about 10 years. He swore by them until one time when it started acting up on a tour. It took him about 3 days to figure out the problem, and he's a very experienced T driver/maintainer/mechanic. Now he doesn't swear by them, he swears at them.
Gross jets are big trouble. I use original needles and seats when ever possible. If you read Hugo Richter's book he describes how to restore one using a drill press and a file, then tapping the needle with a slight blow from a hammer so it deforms slightly to fit the seat.
As a side note, I count four different spellings for Grose Jet in this thread. Although "grose jet" is the correct one, perhaps in view of the number of people who complain about them, "grouse jet" is more appropriate...
Even Russ Potter doesn't use them any more!
Gotta update spell check LOL
The needle and seat is not perfect but maybe a little better than the grose jet.
I was on the way home from a country church picnic yesterday and the T speedster started running rough. I kept going and made it to my farm gate where it died. The switch was still on and I saw fuel coming out of the carb. (electric fuel pump). I pulled off the carb bowl and was able to stop the fuel by pushing up the float.
If I was a little smarter, I would have shut off the electric fuel pump, drained the bowl, and turned the pump back on. It must have been a piece of trash in the needle and seat and the fuel pump would not let the float drop to clear the piece of trash.
In a word- Junk.
I had one on my '26 Touring and I could not get the carb. to stop dripping. I replaced it with one of Larry Smith's new needle valve and seats. Haven't had a leak since.
Larry's needle and seats are perfect reproductions made from Ford blueprints. There is no Viton tip so they are not affected by modern gasoline additives.
I've had one in my '21 Roadster for 20+ years. It doesn't stick or drip but it will starve the carb out if I drive at 45 or over for any length of time. Seldom a problem, so I leave well enough alone.
I've had one on my Kingston 5 ball restored by Russ Potter years ago. Runs flawlessly. I have an in line filter, perhaps that's why.
do larry smith's needle valves work in a 5 ball kingston? i'm not familiar with mr. smith. the viton tipped needle sticks all the time and requires the pressurization of the tank to pop the needle loose in my 1911.
My needle and seats are for the NH only, and are available from most of the vendors. RV has them for the G.
Never had a problem with a number of Grosse jet equipped cars. Never even turn the fuel off, they just work;)
Instead of fooling with all this valve business ya'll need to upgrade to a better carb:
I added this bad boy to my car and HOLY SMOKES it's like driving something with 20 more HP. I could not believe the difference it makes. Idles down slower, starts easier, and accelerates like a bat out of H-E-DOULBE-HOCKEY-STICKS. It doesn't give me any float trouble garbage. You will, however, have to get used to seeing a few drips gas dribble out onto the ground whenever you choke it start up.
Stuart, I would be interested to see how your viton tip needle conversion was done in your 5 ball.
The biggest problem with all the of the needle and seats in recent years has been the formula they use for the gas. Some of the viton tips practically dissolve in the new gas.
Seth, that's what I been telling you boys. Zoom Zoom. Those things really run!
Mr. Stan, I am certainly a believer. I just amazed me what a difference it makes in the way the engine performs. New head? Better exhaust? Different ignition? Psh, first thing anybody should do is get a zoomy carb. THEN, decide if you need other upgrades.
I REALLY want to get a Zenith intake (or any intake for that matter) that is offset like the one in your picture. Right now the only one I could find has the flange oriented parallel with the frame instead of perpendicular, requiring me to use an adapter plate. Also, I can't run my Bosch front plate magneto until I figure out a way to move the carb aft.
If anyone has or sees an intake like that, let me know! Hopefully someone will see one at Hershey or something. This goes for anyone on the board!
stan...without taking the carb apart to inspect, it appears to have a std needle with a , i assume, viton tip and screw in seat. i was told it was done by mr potter some years ago. the tip does not appear to have disintegrated, at least at the time when i did have it apart after i had trouble after purchasing it.
The intake is harder to find than the carb, I think. The carb was easy to get off before the engine was hauled in for scrap or maybe was taken off and saved because it was brass. I don't have an extra intake right now, I have a couple of the carbs.
You have to be careful buying an intake, too. Eldon Townsend made an intake that would let you mount an SO4 that looks similar to the S4BF on a T. They are not as good a carb and the S4BF won't mount on the flange.
I agree with what you said about get a good carb. It was the fastest, cheapest, easiest upgrade in the day and is still about the first thing to do for a good running T.
As far as your 5 ball, I've gone through three different designs to put a modern seat and needle setup in them, I now have one that works and will still flow enough gas. A lot of people -- not Russ -- have used a Tecumseh lawn mower seat and they won't flow enough fuel.
Back to the salt mine.
Don't those Zeniths have a pot metal venturi that goes to "pot"? How do you address that?
I have a Zenith set-up just like that, with the correct Zenith intake. The intake ports, where they meet the engine block, look like they're about half the diameter of a stock T intake. I'm surprised they work as well as folks say. It's what's kept me from using mine. Does your example have small ports as well?
Yes. I machine new Venturi for Zeniths, the pot metal ones are all bad.
Yes. I have wondered about the small ports, too but I wonder if it is not on purpose? It could be to add a second Venturi effect to the intake and also to balance the amount of fuel going to each pair of cylinders. I dunno for sure but I can't imagine a big company like Zenith not doing it for some purpose.