The Grose Jet

Grose Jet

It was a classified add in the Competition Press, the newspaper that became Autoweek, that I first saw it.  “2 Balls do the Trick” was the tag line.  It was an inventor’s replacement for the troublesome needle and seat used in carburetors as a valve to control the fuel that filled the carburetor’s fuel bowl.  The fuel bowl is like a tiny gas tank that is part of a carburetor.  It provides fuel as needed rather than waiting for it to be delivered from the fuel tank.  The needle and seat is opened and closed by the float in the fuel bowl.  When you re-built a carburetor setting the upper and lower limits of the float was critical to smooth performance.  As the fuel is sucked out of the fuel bowl the float sank and pulled the needle away from the seat allowing gasoline to flow into the bowl until the float reached the point that the needle was pushed against the seat and shut the flow off.   The “needle” was shaped much like a rod with a cone on one end.  The rod was usually not round.  It had three or four flats so that the fuel had less resistance as it flowed past the cone end.  The cone end came in contact with a seat that was angled much like the seat that an intake or exhaust valve seats against.

Over time the cone would develop a ring wear pattern where it constantly came in contact with the seat.  They were usually both made of brass, but sometimes neoprene was used for the cone part to try to limit the wear pattern.  Once the ring was worn into the seat, the valve never worked as it should and affected the carburetor’s performance.

Mr. Grose had the bright idea of completely re-designing the needle and seat valve.  His idea was to use a ball bearing that would constantly present a new surface to the seat and therefore provide a consistent metering of fuel.  A large ball was used as the surface that the float would act against while a smaller ball would come in contact with the seat.

It was a simple and elegant solution to pesky problem with carburetors.  The race car world loved it.

Carburetors were complex devices that performed a very simple function.  Carburetors atomized the fuel so it could be burned.

When gasoline is in its pure liquid form it doesn’t like to burn.  I used to watch guys throw their cigarette buts into a pail of gasoline and put out the cigarette.  DO NOT EVER DO THIS!!!  It was a stupid thing to do because if there was ever enough gasoline vapor above the liquid it would have been tragic.  The point is that for a gasoline engine to work well the fuel burns best when it is mixed with air.  The ideal ratio is about 14 parts air to one part gasoline.  This is not a constant though, which is why carburetors are so complex.  The ratio must constantly change based on manifold vacuum, throttle plate position, engine temperature, and on and on. 

If you want to see a simple example of how a carburetor atomizes fuel look at a spray bottle of window cleaner.  As air is pushed across the top of a hollow tube a vacuum is created that pulls up the liquid and mixes it with air forming a spray mist.

One day I decided to drive up to Stoneham, near Boston, and pick up a Grose Jet.  This was in the days before Mapquest or GPS so I looked up the address in the ad and found a map of the town.  It was called D & G Valve Mfg. Co., Inc. on 8 Mt. Vernon Street, and I really did not know what to expect.  Would it be a large brick factory with chain link fence and guard house?

It turned out to be a house in an old Stoneham neighborhood.  I went to the door and knocked.  A large man with a machinist apron on greeted me and invited me in to the manufacturing shop set up in the basement of his house.  He wanted to know what model of carburetor I needed a gross jet for.  Since I was there I picked up one for the Quadrajet on my mother’s Pontiac as well as the Holley on my VW.  He took the time to show me how his jigs were set up to manufacture the different Grose Jets.  For motorcycles he used glass for the larger ball to keep the mass down and deal with the vibration better.

He pulled two Grose Jets out of the drawers of his cabinets and sold me what I was looking for. 

I drove home enlightened to see what a Yankee inventor could produce out of the basement of his house and become famous for in an underground sort of way.

Look up D & G Valve on the Internet, you can still find it.  Amazing.

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102 Responses to The Grose Jet

  1. David Knight says:

    I have been trying to reach the D & G Valve Manufacturing, Inc. without success. I have picked up two phone numbers from Thomas Registry’s web site, but both have been reassigned. They are: 617-438-1789 and 1773. The party to which these numbers have been assigned do not know of the company and have had these numbers for about four years. I am wanting to purchase one of the “Grose-Jets” to replace the needle valve on my 1936 Oldsmobile which has a Carter WA-1 carburator. Can you offer me any help. Perhaps if I knew Mr. Grose’s first name I could reach him that way.

    Thanks for any help you can give me.

    David Knight

  2. jimsgarage says:

    Ansel B. Grose of Stoneham, Middlesex, Massachusetts, died in 1981. The patents on his invention, the Grose Jet, have expired. The D & G Valve Manufacturing Company no longer exists, even though I have been able to find it listed in
    I remember when I visited Ansel and he gave me a tour of his manufacturing facility that he mentioned how he used a similar device for the ice cream machines at Dairy Queen.

  3. jimsgarage says:

    You can look through the United States Patent Office records and pull the expired documents. If you have the wherewithall you can try making your own. I know the link in my story to Stromberg carburetors shows how one company did just that.

  4. Russ G. says:

    To paraphrase Mark Twain: “The reports of Mr. Ansell Grose’s death are greatly exaggerated!” I can assure one and all that Ansell Grose was drawing breath quite well as of Monday, November 27, 2006, as was his newly born baby daughter! The Ansell Grose who passed away in 1981 was undoubtedly Ansell the Elder!

    As for the phone number being inoperable, you are mistaken. The Area Code for Stoneham, MA is 781, not 617, and has been for about two decades. Admittedly, it’s still difficult to reach Mr. Grose by telephone, but appear in person at his modest residence during most any weekday, and if you see a large red pickup truck in the driveway, Mr. Grose will generally be there to greet you.

    It is true that manufacture of the Grose Jet was begun, and is still done, on screw machines initially used to fabricate parts for soft-serve ice cream machines. That has absolutely nothing to do with the quality of the product, nor does the fact that the original patent may have expired. It will still cure your carburator flooding woes for less than you’d pay for an OEM rebuild kit. These will outlast and outperform the common brass seat and rubber-tipped needle. Now that gasoline contains a significant amount of corrosive alcohol, it’s no contest – the all-metal valve comes out on top.

    • tim kingsbury says:

      Hi Russ – you seem you seem to have a bit more of a connection than does the rest of us so I am hoping for some help. My Sleuthing (not that I doubted you) was Ansel SR died in 1981 and his Wife Marilyn inherited the company, or the registry was changed into her name. Maybe that is the easiest explanation. For 100% sure the company was formed on July 24 1958 and there was a court order on may 31 2007 that is classified as Involuntary Dissolution of the company. The Phone service appears to be voluntarily terminated on June 30 2007. Long story to that, but the number I had was disconnected at that time, and was reassigned in 2010. I can’t find out who too, but I can tell you there never is an answer.

      No I was talking to someone at Spring Carlisle that suggested that the original company in terms of a name, ceased at the end of may in 2007, but that Ansel (jr I will call him) had another LLC company and continued right along. He seemed to think there was some technical issue with the company and the estate of his dad and the irs (that never surprises me) and so they had company a shut down, but started right up with company b. But then he had no new phone number.

      I did send a letter, but that was returned last week as undeliverable.

      So I am back at a dead end. I also realize you posted your note 6 years ago so
      I am grasping at straws. But hey, the grose jets are just the best thing since sliced bread and after using them for 20+ years.. actually might be crowding 30.. It is a tough habit to quit. If I could find them or goodness I hope if something happened to the younger Ansel that someone takes over.. I would happily place a substantial order to definately make it worth while.
      Tim Kingsbury
      email –

  5. Dennis Bayer says:

    I have tried phoning at least 100 times, maybe more. I have even sent a letter. I have one Grose Jet that I got years ago and would like to get a few more.

    I actually need it for a Solex 32 PBIC carburetor. Since I can’t contact D&G I have been wondering if the Grose Jet for later MGs, etc with Zenith Stromberg carbs, might fit. I know that early Zeniths were very similar to Solex and most parts were interchangeable.

    I have seen a photo of the Grose Jet that goes with that carburetor. What I would like to determine is whether it is the same size as the Zenith ones.

    I measured the threaded end and the hex for screwing it into the carburetor top on the one I have for my Solex. The Threaded portion is 11.90 mm diameter or about 15/32 inches. The hex is 14.35 mm or about 9/16 inches. This is what I would like to have checked out. It would be for the Zenith NOT the SU that earlier MGs used. I think the Moss Motors part number is 386-350. I want the GJ for a 1953 Citroen Traction AVant.

    Thank you very much,

    Dennis Bayer

    Sausalito, CA

  6. Pingback: Famous Inventors

  7. Linda Emmick says:

    Do you make the mikuni car grose jet for the 34MM carb??
    number 114?
    Please let me know.
    Thanks Linda Emmick

  8. John Titus says:

    Look for the new Weber 501 Grose Valve on Ebay in early 2009 (Fits Weber DCNF, DLD or any other Weber that takes a Weber 175 or Weber 200 needle and seat). Search text “Weber Grose Valve”

  9. So what is the verdict, are Grose jets still available or not. If the answer is ‘yes’ give me a hint to a business that sells them. I am looking for Carter and Rochester applications. THANKS

  10. jimsgarage says:

    Good question Steve. I can only guess that Ansell Grose still has them if you can travel to his home as listed above.

  11. Thanks for the idea but my shop is in Golden, Colorado. That is a rather long drive when there is no information about his inventory. I guess I don’t understand why a business won’t answer their telephone.

    Where is everyone with other carb brands finding the parts? Thanks for the info however.

    Best, Steve

  12. James Howard says:

    I was able to buy a Grose jet from Ernie’s British Car in Tucson, AZ last year. 520-888-3055.

    • robert reeves says:

      I am looking for Grose-Jet to fit a Stromberg UUR2 carb. Part no. STM-UUR2 . Any help on where I might get them? Surely someone bought up the old stock from D&G Valve Mfg. Co.

      • Lloyd says:

        Robert… Were you able to find a source for the Grose-Jet for the american built cars as in GM rochester carbs? Please let me know. Thanks Lloyd

      • John Titus says:

        The Stromberg Grose Jet (now called an “S-Jet” maybe to avoid trademark issues?) is available from It fits Stromberg 97, 48, 81 and 40. Since the patents to Ansel Grose have all expired, anyone with the resources can make the equivalent of a Grose Jet. You just have to find someone interested in making 1,000 jets, then someone who is interested in investing in the inventory, which may sit for years and years.

  13. jimsgarage says:

    Thanks for that information – I found they have a web site:

  14. John Titus says:

    As promised, the Grose Jet 501 is available again to fit any Weber that takes a 175 or 200 needle and seat, including DCNF, DLED, and probably others. Photos at

  15. jimsgarage says:

    Thank you John! I am certain that you have made several enthusiasts happy.


  16. tim kingsbury says:

    Well folks.. I think I have called 781-438-1789 a million times.. bet at least 1000.. and never got an answer.. I have writen, no answer.. It would be a 17 hour drive for me, but I have to tell you, 20 years ago I bought a bunch of jets off Ansel Grose, and do not seem able to get ahold of him

    I am looking for them for older Carter Ball and Ball carbs for early Chrysler/Desoto/Plymouth/mopars as well as for some newer stuff. Can any one confirm it is worth the drive.. aka anyone talk to him in the last 12 months.. by phone, mail, in person.. ?

    Appreciate the info


  17. jimsgarage says:

    I searched on the web and found this interesting story on Grose Jet:

  18. Derrick says:

    I ran into this looking for grose jets myself. Looks like they closed up the company back in 2007.

  19. Rick Parker........... says:

    The principal of the business (the inventor-machinist) died some time ago.
    Looking for Weber IDA fitament.

  20. Dennis says:

    Does anybody know where I can get a Grose Jet for a Solex Carburetor (Citroen)?

  21. Hmm is anyone else having problems with the pictures on
    this blog loading? I’m trying to find out if its a problem on my end or if it’s
    the blog. Any suggestions would be greatly appreciated.

  22. Jim's sister says:

    Nope. No problems seeing pics.

  23. Stan says:

    I hesitate to tell you all that I have 2 cases of grose jets. Carter YF,AFB,BBD,TQ, the BBD may fit early Carters. I need to check the thread pitch. Also for Holley 2 and 4 bbl and Rochester 4G and Autolite 2 & 4 BBL and SU. I have these from being in the carb business for over 25 yrs. The email is not my business one, it is so I can get some work done. Contact this way and I’ll see if I can help.

  24. Ted Harbit says:

    How do we contact Stan?

  25. Stan says:

    I have both AFB & Holley, leave me a phone number. Still working on Carter.

  26. tim kingsbury says:

    hi stan – if you can drop me a line to

    I found some old packaging.. the ones for carter ball and ball all start with CT-TQ and then
    anything over size are after that.. so CT-TQ .130 are what I have in my 49 plymouth.

    But I would be interested in any ct-tq jets you might have.

    The carter quadrajets are ct-13

    I still have some of those but would be interested if you do have stock. But the carter ball and balls are the ones I can really use


  27. tim kingsbury says:

    Hey Stan – did you ever find any jets for old mopars for me ?

  28. Stan says:

    Need phone numbers. Read previous post on what I have in stock.

    • tim kingsbury says:

      You said you were still looking at the carter stuff.. so if you have any

      carter ball and ball all start with CT-TQ and then
      anything over size are after that.. so CT-TQ .130 are what I have in my 49 plymouth.

      But I would be interested in any ct-tq jets you might have.

      The carter quadrajets are ct-13

      Phone number is 519-856-4576 or just email me at

    • Bill White says:

      Any chance you have any T-901 Grose Jets? They would be .099 and be for a Tillotson carb on a HD motorcycle. Please e-mail me at or call 585-455-4814 with any info.

  29. tim kingsbury says:

    Hi Stan – my phone number is 519-856-4576 or if easier email me at with your phone number and I can call you.


  30. al says:

    Hi, I am looking for a grose jet part number CT1 and BS2 for an old motorbike I am currently restoring. These seem to work extremely well for this application. Does anyone who know where I can pick these up?
    Thanks in advance

  31. John Geddes says:

    Hi Stan

    This is John ,
    360-393-0270. Looking to get 2 sets of Carter AFB Grose Jets if at all possible. Thanks

  32. Gabriel Saretta says:

    Hey someone can tell me were I find the ball valve type needle for 45 dcoe…were to buy…I´m from Brazil

  33. Bill McLaughlin says:


    Would you have a MS-71 ?


  34. Joel Hardin says:

    just scored a set of GJs for my nikki ( rx7) and hope to find more…. these were in the D&G baggies as original

  35. Joel Hardin says:

    welp, spoke too soon. theyre not the right ones for a nikki.

  36. Ab Tiedemann says:

    Looking for Grose-Jets No. 201 or 402. 201 is for a Solex Carburetor 40 PII-4 and 402 is for a Zenith 32NDIX.

    • Tim Kingsbury says:

      All I can say folks is Stan never replied to me or anyone else since 2013. What I can tell you is I see Grose Jets from time to time on ebay. Right now there are a few for sale, and if you click on advanced and search completed auctions there are about 70 recent auctions. All I can say is keep an eye on ebay and other secondary sites. Sadly the ones I looked for have never come up for sale and it looks like the legendary Grose jets will never again be produced. Multiple people have tried to get some one to restart the company, then tried to purchase what would be required to restart producing the jets. Nothing but dead ends sadly. So what product is out there is out there and when it is gone I fear that is it.

  37. DavidB says:

    Jim, just came across your story while searching for information on Grose Jets. I had an experience almost identical to yours when I met the man (Sr) himself around 1978 looking for a jet for the Holley-Weber in my 2L Pinto (don’t laugh). I just met him at the door, didn’t get a tour of the shop – wish I’d asked!

    It is a little surprising nobody’s continued production of the jets, as it should be fairly easy to copy the geometry and flow requirements from an OEM jet assembly. I should put “easy” in quotes, as it may be tougher to match properties than I realize, but as a machinist/car geek myself I know it can be done. it’s more an issue of can it be done without crazy pricing…

    • John says:

      The patent is expired last I checked, so if you are headed in that direction, better to make that move before someone else does. Let us know when you do so I can think about running a WCFB without having it cut out on sharp turns. Even a 4GC could be a nice carb when jetted right and Grose jets installed. I’ll wait, but only until my Grose jets become available again!

      • DavidB says:

        Hi John, thanks for the thought! It’s a little tempting, but I’ve got other fires burning that must be dealt with before I’d take something like this on. Among other things, I’d think a liquid (but not gasoline!) flow bench would be needed to confirm behavior of OEM jets before trying to match them with GJ-style mechanics.

        I’m open to the idea, but what would the market allow for pricing? At the low volumes and need for research to do it right there’d have to be some cost for these guys…

      • John says:

        Maybe there is more to it than I am aware, but once youre in the ballpark, carbs’ Grose jets could be tweaked to optimum performance. I’m not referring to hot rodding, just running lean and mean. I dont think carbs need reinventing, the automotive engineers already did their job. This is an aftermarket/afterthought that just worked really well. Wer’e talking about not overfilling a float bowl, not calculating atomization, venturi science or any of that.

      • DavidB says:

        Hi John,
        I think there’s more to it then that. Some OEM needle seats and pintles might give a non-linear response to opening distance to maintain bowl level at a certain volume. I haven’t played (or read up) in this area for a long time, so maybe it is generally just a valve and flow profile is handled elsewhere in the carb. If there’s more experienced people who can give a yes-no to that I’d like to hear it.

      • John says:


        My buddy who told me about GJs says he sets his bowl a little lower in order to run GJs.

  38. WNorth says:

    Is there a way to reverse engineer what model number Grose jet I have from the actual part? I have dimensions and pictures but they are installed in a unique application where the part number is not available. I strongly suspect they were “borrowed” from another application, maybe a Tillotson as other parts were borrowed from Tillotson (springs, lever, pins, diaphragm.)

    It is short, open length is .500″, closed length is .450″, hex is 5/16″, threads are 5/16-32, glass upper ball, steel lower, inlet port .125″, outlet holes are in the hex flats .075″ x 6 ports, gasket sits at bottom (no flange).

  39. WNorth says:

    Here is a picture of one sitting next to an 8/32 tap. It is used in an aviation TBI system that borrows parts from other applications like the levers and diaphragms are from Tillotson HD carbs. So I have no way to know what the original PN or application was… other than to say it’s somewhat close to the 07-415 Grose-Jet. I was hoping someone might recognize it.

  40. Gabriel Saretta says:

    Hello guys! I´m from Brazil, have a triple weber on my drag car…50dco…looking for the grose jets for them…are the same as the 45 dcoe…but I can´t find anywere. If someone could help me..

  41. Allen says:

    I am looking for the same grose jet as W North is. Does ant one know of a place to purchase it?

  42. Allen says:

    W North, did you ever find this grose jet?

    • John says:

      Nice to hear, but the remaining leftover stock has been bought up. There was a time someone was taking orders, but I would have had to have bought an entire production run of what fits the WCFB and the 4GC. Two carbs that just do not function properly with the original needle and seat.

      • Allen says:

        What a shame, You would think that there would be a replacement or an alternative but if not then the only thing I can do is order a replacement carburetor. Cost would be about $800.00 when I could fix it for less that $100.00. A co. in Calif. will rebuild it for $850.00 and then I have an old $850.00 carb. I will keep looking and hope something will turn up. If not in the next 2 weeks I will bite the bullet and buy new.

      • John says:

        Yep. Edelbrock without the flooding problems on right turns or washboard gravel roads is an option, but not as vintage and no cast iron base. Bigger venturis, too. I believe it requires making a 1:8” thick aluminum adapter as well.

    • WNorth says:

      Nope, I never found a source

  43. tim kingsbury says:

    Well guys – back some time ago this post was put up –

    “Mike Brown says:January 2, 2018 at 10:32 am
    We’re doing a run of 1,000 Grose-Jets on our Swiss Machine for the Fish Carburetors we manufacture. If you need 100 or more for a particular application we can simply extend our production run. – Mike Brown (417) 887-8919 or

    Now at one point the sheet I had from Ansel Grose covered 270 different carbs. The challenge as I see it is even if your rebuild a lot of a specific carb as we do with carter ball and ball carbs, to get 100 of the 12 different sets we use is 1200 sets of jets and while the Grose Jets were hands down the best we have ever seen and have been rebuilding them for 60+ years, the investment just exceeds anything close to what we would use. But hey there is his email, cant hurt to ask.

    Tim Kingsbury
    AoK boys

  44. Frank Correia says:

    Thanks for the reply. I guess I’ll have to remove the valve again and search for a # on it as the Grose jet that is in my “special” billet Dap 34-35 slide carb dosent look like those jets for sale now.

    • tim kingsbury says:

      yes, as there is definitely nothing listed on the Grose offering sheet for any such carb, so I am sure you or someone provided Ansel Grose with a jet number or details. In any case I dont have nor do I know anyone with a stock of Grose jets for sale. Its been what comes up on ebay and of course the person who offered to make them but it was a 100 jet minimum and that was also while he was running 1000 for another purpose so who knows if even 100 min would be available. But certainly pulling out the jet and getting the number would be a start. Then compare them to what is for sale on ebay or perhaps put up a listing here or elsewhere with the Grose jet number your looking for. Best I can suggest

  45. Jeff Driggers says:

    Does anyone know where I can get a grose jet #T-901 for a vintage tilltoson he snowmobile carb.Any info would be greatly appreciated

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