Weber 32 DFD or DFM for Cortina ???

[Art Smith]

what's the preferred Weber for Cortina's, Weber 32 DFD or DFM ??? AND why??? I have three cores in a range of conditions for each type so parts shouldn't be the deciding factor.

how is the preferred Weber for Cortina'a functionally different than the Weber 32/36 DGV used on uprated Kent's (other than different top) ??? wondering why different carburetors are required for the two Ford engines...................................

Art
artesmith@earthlink.net

[azjc]

I'd have dig through some old Weber info... but as I recall a DFM has the primary & secondary reversed compared to a DGV, the DFM is also 32mm on both the primary & secondary, the DGV is 32mm primary & 36mm on the secondary.

[Art Smith]

the internet refernences I've found and my Weber refernece books indicate that [FONT=Univers][FONT=Univers]Weber 32/36 DGV, [FONT=Univers][FONT=Univers]Weber 32 DFM, and Weber 32 DFD ALL have a 26mm primary venturi, ALL have a 27mm secondary venturi, ALL use interchangeable main fuel jets, ALL use interchangeable air correction jets, ALL use interchangeable emulsiom tubes, ALL use interchangeable idle jets, and ALL use interchangeable idle adjustment needles. the older Weber's have a different aircleaner interface[/FONT][/FONT][/FONT][/FONT]

[FONT=Univers][FONT=Univers][FONT=Univers][FONT=Univers]IF there's a performance potential difference, surely someone should be able to verbalize it! IF there's not a performance potential difference, why are Cortina engines not permitted to use the newer, more readily available, and less expensive Weber 32/36 DGV used on Kent's ???[/FONT][/FONT][/FONT][/FONT]

[FONT=Univers][FONT=Univers][FONT=Univers][FONT=Univers]Art[/FONT][/FONT][/FONT][/FONT]
[FONT=Univers][FONT=Univers][FONT=Univers][FONT=Univers]artesmith@earthlink.net[/FONT]
[/FONT][/FONT][/FONT]

[azjc]

The 32mm & 36mm are the throttle bore size, so a 32/36 can actually flow more air then a 32/32. Here's a pretty complete listing of Ford's that use Weber carbs directly from Weber's 1977 edition:

[Art Smith]

John-

your reference, as mine, show 26mm primary and 27mm secondary venturi for 32/36 DGxx Weber's.

the venturi throat diameters and the local speed of sound bound the amount of air the engine can draw just like a "single inlet restrictor"....................................... .

Art
artesmith@earthlink.net

[azjc]

John-

your reference, as mine, show 26mm primary and 27mm secondary venturi for 32/36 DGxx Weber's.

the venturi throat diameters and the local speed of sound bound the amount of air the engine can draw just like a "single inlet restrictor"....................................... .

Art
artesmith@earthlink.net

Not really... we are dealing with a venturi (the choke) which speeds up the air and creates low pressure to draw the fuel in, the throttle plate is the flow restrictor. Ever run 40 & 45 DCOE's on a flow bench with the same choke size? 45's will flow more air then a 40 when both are using the same choke size. Difference was in power curve and driveability.

In IMSA on a BMW we could take a 32/32mm Solex and replace with a 32/36 weber and gain engine power. Choke sizes were about the same as I recall.