AF small bore inlet manifold

[Juggler]

Ford was never bothered about any mismatch of diameters between carb and inlet manifold

In England the Kayse carb had the same dimensions as a Zenith, the only difference being being different jets and smaller diameter pot metal Venturi.

The small bore AF engine had an inlet manifold of 1" diameter, mated to the Zenith style card with a 1" 3/8ths diameter, so a "big step" in the inlet tract. The engines ran just fine like this

Where the AF manifold mounted to the block, they belled out to match the block so the same exhaust manifold gasket was used.

Message from John Charlton in sunny Suffolk county UK

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[Brad in Germany]

Hummm, is that intake manifold for a RHD car (with the little knob on the top left side for the spark control linkage)?

Interesting looking at the various European Model A parts books (all which include AF parts), only the French parts book lists two different parts numbers for the top part of the carburator: A-9520 and AF-9520 both described as "Partie supérieure du carburetor" ("Upper/top part of the carburetor").

The assumption is that AF-9520 would be the top part of the carburetor with the smaller bore throat in which case it would match up with the smaller bore intake manifold.

Also that French parts book lists two parts numbers for the throttle plate (see the last two parts listed on the parts book scan above): A-9585 and AF-9585 where the latter would be for the smaller bore AF carburetor throat.

So maybe the mis-matched diameters that you describe (in the original post) is a UK thing?

Vive la France,
Brad in Maryland



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[john charlton]

Hi Brad

The English built cars were factory fitted with a "KAYCE" carb . I have one as removed from a one family owned 1929 tudor sadly rodded . It does not have the smaller throat but has the AF jets and smaller dia venturi . AF 9510-B is listed in July 1st 1931 English parts book for the 3" bore engine so maybe did not have the smaller throat just different jets and venturi . The 3 7/8" carb is AF 9510 C . No listing for smaller butterfly etc etc so maybe a France only thing .The inlet manifold pictured is a RHD with the peg on top . KAYCE became QUALCAST and are still in business making lawn mowers ! No listing for a separate top with AF prefix

John in rain on the way in Suffolk County England .

 

[johnbuckley]

A snip from our UK "Bert Thomas Manual" -( a compilation form various sources) . Personally I've used 21.4 mm venturis in the carbs for the smaller bore engine and not detected any difference....!