B carb needle jet size

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Ernest Moreno
Posts: 1
Joined: Sun Dec 31, 2017 4:04 pm

B carb needle jet size

Post by Ernest Moreno »

I am presently converting my Pietenpol to Model A power and have a question about the use of the Model B carb. In its original configuration it had a number 44 needle jet that was used in conjunction with a fuel pump, but in a gravity feed configuration it was changed to a 54 needle jet size. Is this what people are using in this application? Also would like any info on mods to carb that should be made to enhance running operation.

Ernie Moreno
Independence, Or.
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Richard Roller
Posts: 240
Joined: Mon May 22, 2017 11:14 am
Location: Olathe, Ks.

Re: B carb needle jet size

Post by Richard Roller »

Ernest,
While working to get Ken Perkins engine back together for his Piet, I ran across a drawing he made of a needle and seat for gravity fed carburetors for model a Fords with a 'B' carb. If you haven't solved your problem yet I could scan the drawing for you and sent it your way.

Richard
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taildrags
Posts: 637
Joined: Tue Mar 07, 2017 10:39 pm

Re: B carb needle jet size

Post by taildrags »

By all means, please post the drawing of the needle and seat on this list. This question seems to have come up repeatedly.
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Richard Roller
Posts: 240
Joined: Mon May 22, 2017 11:14 am
Location: Olathe, Ks.

Re: B carb needle jet size

Post by Richard Roller »

model b ford jet and needle valve.pdf
(1.07 MiB) Downloaded 349 times
A drawing Ken made for a needle and seat for a model B ford carb for use on a gravity system on a Pietenpol.
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Richard Roller
Posts: 240
Joined: Mon May 22, 2017 11:14 am
Location: Olathe, Ks.

Re: B carb needle jet size

Post by Richard Roller »

Some additional info. When Ken was first running his Piet he had some fuel supply problems. The solution was not in the jet size, but in fuel supply through the needle/seat combination. Ken initially drilled the seat to increase the flow. Then he had another problem in that the needle couldn't stop the flow completely. Bleed by and a overflow mess when the engine wasn't running. So he made his own needle/seat unit. It works very well.
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