The Ford Barn

plind · 03-16-2022, 01:05 PM

Hi.. How do i find the 100% correct measurements on Jets for a Zenith/holly from Dec 1927 with Double venturi.. ?
I`m thinking to get a machinist to make a complete set for restoration ... i do not know where to buy them at the rigth length...

Thanks..
Per from Denmark

plind · 03-22-2022, 02:16 PM

Btt

Ed in Maine · 03-22-2022, 03:28 PM

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Hello Plind, these jets are readily available here in the states but usually they need to be flow tested. Very often they are oversized. Using the "Zenith Model A Carburetor Restoration Guidelines" by Steve Pargeter. There is a diagram on page 9 which shows the lengths of the jets: Idle Jet - 3.1 in., Cap Jet - 1 3/32 in., Main Jet - 1 15/32 in. These dimensions are from the machined seating surface by the threads to the tip of the jet with exception of the Idle Jet where the dimension is the total length. There is a paragraph associated with the dimensions and I state as follows: The double venturi carburetor did not originally use a separate removable secondary well so to compensate, the idling jet was longer than in the later single venturi carburetors. The double venturi Idling Jet was about 3.1 in. long and normally marked with the number 10.

I would buy these from Snyders Antique Auto Parts, New Springfield, Ohio. They are on the internet. Be sure to mention that you need the longer Idle Jet for the Double venturi carburetor. If you can't find them, I believe you could lengthen a 3.0 in. Idle jet (single venturi) using brass shim stock.

I hope I answered your questions. Ed

03-16-2022, 01:05 PM	#1
plind Senior Member Join Date: Sep 2010 Location: Denmark Posts: 330	Zenith/Holly VE 28 Jets Hi.. How do i find the 100% correct measurements on Jets for a Zenith/holly from Dec 1927 with Double venturi.. ? I`m thinking to get a machinist to make a complete set for restoration ... i do not know where to buy them at the rigth length... Thanks.. Per from Denmark __________________ www.forda1927.dk Tudor * A 2820 * Town Sedan * A 4472283 * Orig.never restored. Last edited by plind; 03-22-2022 at 02:15 PM.

03-22-2022, 02:16 PM	#2
plind Senior Member Join Date: Sep 2010 Location: Denmark Posts: 330	Re: Zenith/Holly VE 28 Jets Btt __________________ www.forda1927.dk Tudor * A 2820 * Town Sedan * A 4472283 * Orig.never restored.

03-22-2022, 03:28 PM	#3
Ed in Maine Senior Member Join Date: May 2010 Location: Washington Cty., ME or Flagler Cty., FL Posts: 1,106	Re: Zenith/Holly VE 28 Jets Sponsored Links (Register now to hide all advertisements) Hello Plind, these jets are readily available here in the states but usually they need to be flow tested. Very often they are oversized. Using the "Zenith Model A Carburetor Restoration Guidelines" by Steve Pargeter. There is a diagram on page 9 which shows the lengths of the jets: Idle Jet - 3.1 in., Cap Jet - 1 3/32 in., Main Jet - 1 15/32 in. These dimensions are from the machined seating surface by the threads to the tip of the jet with exception of the Idle Jet where the dimension is the total length. There is a paragraph associated with the dimensions and I state as follows: The double venturi carburetor did not originally use a separate removable secondary well so to compensate, the idling jet was longer than in the later single venturi carburetors. The double venturi Idling Jet was about 3.1 in. long and normally marked with the number 10. I would buy these from Snyders Antique Auto Parts, New Springfield, Ohio. They are on the internet. Be sure to mention that you need the longer Idle Jet for the Double venturi carburetor. If you can't find them, I believe you could lengthen a 3.0 in. Idle jet (single venturi) using brass shim stock. I hope I answered your questions. Ed