Carb identification help

gearheadbill

Senior Member
I know nothing about stock Model A’s but recently purchased an 31 deluxe coupe. It’s an older amateur restoration from 1980. It’s been sitting for several(?) years and my first order of business is to get it running. Pulled all the fuel system components to clean all the crud and varnish. I’m trying to identify the carb used. It doesn’t look like the pictures of either zenith or tillotson carbs that I’ve seen.
 

Attachments

  • 3A40A309-984D-4867-8B09-55C569F66B33.jpeg
    3A40A309-984D-4867-8B09-55C569F66B33.jpeg
    33.2 KB · Views: 142
  • B5889AF9-BAFB-43B6-84D0-3E3112AB2914.jpeg
    B5889AF9-BAFB-43B6-84D0-3E3112AB2914.jpeg
    22.6 KB · Views: 123
Actually that is a very good carburetor for the Model A. They run better than the Zenith. They have a power circuit in them which gives it better drivability.
 
Marvels have two different GAV needles/parts. One of these has the "half circle" Model A GAV (in fact the GAV and driver are interchangeable with the Model A Zenith) the other has a "hex" shape on the GAV needle and a matching driver.

The Model A version has parts available, the Hex version does not. The Renner Kit shown above appears to have the Model A type GAV needle.

If you talk to Renner they might have the other kind of needle to sell separately.

Or hang around your local antique auto flea market. You may find a seasoned veteran Marvel-Schiebler for as little as $5. They are EXTREMELY common. If you see a hex version - MAKE SURE IT HAS THE DRIVER because drivers are not available - although they can be made using a 1/4 drive six point socket and a modified Model A driver. But that's a lot of work.

Joe K
 
Marvels have two different GAV needles/parts. One of these has the "half circle" Model A GAV (in fact the GAV and driver are interchangeable with the Model A Zenith) the other has a "hex" shape on the GAV needle and a matching driver.

The Model A version has parts available, the Hex version does not. The Renner Kit shown above appears to have the Model A type GAV needle.

If you talk to Renner they might have the other kind of needle to sell separately.

Or hang around your local antique auto flea market. You may find a seasoned veteran Marvel-Schiebler for as little as $5. They are EXTREMELY common. If you see a hex version - MAKE SURE IT HAS THE DRIVER because drivers are not available - although they can be made using a 1/4 drive six point socket and a modified Model A driver. But that's a lot of work.

Joe K

What’s a GAV and driver please?
 
Renner's has the hex needle and driver.


Bob
 

Attachments

  • s589187565737478790_p79_i1_w1059.jpg
    s589187565737478790_p79_i1_w1059.jpg
    22.2 KB · Views: 21
  • s589187565737478790_p83_i1_w816.jpg
    s589187565737478790_p83_i1_w816.jpg
    23.4 KB · Views: 21
What’s a GAV and driver please?
The GAV is short for "gas adjustment valve."

On a Model A Ford this is the knob below the dash over to the right in front of the front seat passenger. Normally open quite a bit maybe a full turn on starting, it is closed down to perhaps a quarter turn open once the engine is fully warm.

A GAV "needle" is the functional part alongside an orifice in the carburetor. The "driver" is the part you see on the exterior of the carburetor and is the part connected to the rod extending to the driver/passenger control.

Not related to the GAV per se - a "choke" of the engine is achieved through the GAV driver by pulling "up" on the driver/passenger control. Hence the use of a hex or "half moon shaft" which allows this sliding to happen and still have control of the GAV needle.

I see above Renners DOES have the hex part and driver. Which is good. While a driver can be cobbled together from parts, how do you value your time?

Joe K
 
The GAV is short for "gas adjustment valve."

On a Model A Ford this is the knob below the dash over to the right in front of the front seat passenger. Normally open quite a bit maybe a full turn on starting, it is closed down to perhaps a quarter turn open once the engine is fully warm.

A GAV "needle" is the functional part alongside an orifice in the carburetor. The "driver" is the part you see on the exterior of the carburetor and is the part connected to the rod extending to the driver/passenger control.

Not related to the GAV per se - a "choke" of the engine is achieved through the GAV driver by pulling "up" on the driver/passenger control. Hence the use of a hex or "half moon shaft" which allows this sliding to happen and still have control of the GAV needle.

I see above Renners DOES have the hex part and driver. Which is good. While a driver can be cobbled together from parts, how do you value your time?

Joe K
Thank you for the very clear explanation.
I place no value on my time fussing with old cars. 100% recreational
Thanks again.
 
Back
Top