Zenith 3 and Gemmer steering box - Help

[Synchro909]

I know that Ford made a hack of the first design for the RHD gemmer steering box. They found their first attempt fouled the carburettor so they put the end play adjustment for the worm on the side of the box. I have just tried to fit a Zenith 3 to an A motor (after enlarging the bore of the manifold) and have a Gemmer steering box already fitted. It is a no go. Was the carb mounted higher on the B engine than the A? Does anybody have a picture of a RHD car fitted with a B motor. One of my other Model As has that but it also has a downdraught carby so no help.

[juke joint johnny]

I have had several A + B Carbs that have had a bit cut off of them to clear the steering column on RHD cars .
I have wondered if a sagging frame or a worn out front engine mount could be the cause of the problem !!

[Chuck Sea/Tac]

You mean a B carb, because a zenith 3 has the same bore as the earlier versions.

[woofa.express]

Originally Posted by Synchro909

I know that Ford made a hack of the first design for the RHD gemmer steering box. They found their first attempt fouled the carburettor so they put the end play adjustment for the worm on the side of the box. I have just tried to fit a Zenith 3 to an A motor (after enlarging the bore of the manifold) and have a Gemmer steering box already fitted. It is a no go. Was the carb mounted higher on the B engine than the A? Does anybody have a picture of a RHD car fitted with a B motor. One of my other Model As has that but it also has a downdraught carby so no help.

Hi Synchro. I can't help you but maybe you could help me. I'd like to replace my 7 tooth steering box with a two tooth- a 30 or 31 Gemmer. Do you have a spare you could part with? cheers, gary

[Synchro909]

Originally Posted by Chuck Sea/Tac

You mean a B carb, because a zenith 3 has the same bore as the earlier versions.

I think you're right. The carb has a larger throat, a squarish float chamber and the fuekl inlet is at the front (radiator) side It has ZENITH cast vertically in the bowl. I think I realised a contributing factor last night. These carbs are notorious for the mounting ears breaking off. Mine had one broken to I made a 1/4" thick plate which I brazed on the top. That will have lowered it 1/4" but I'd be surprised if that was enough to cause the issue.

[Synchro909]

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Originally Posted by juke joint johnny

I have had several A + B Carbs that have had a bit cut off of them to clear the steering column on RHD cars .
I have wondered if a sagging frame or a worn out front engine mount could be the cause of the problem !!

Thanks for the input. The chassis is straight and the front engine mount is new.

[Chuck Sea/Tac]

Originally Posted by Synchro909

I think you're right. The carb has a larger throat, a squarish float chamber and the fuekl inlet is at the front (radiator) side It has ZENITH cast vertically in the bowl. I think I realised a contributing factor last night. These carbs are notorious for the mounting ears breaking off. Mine had one broken to I made a 1/4" thick plate which I brazed on the top. That will have lowered it 1/4" but I'd be surprised if that was enough to cause the issue.

Yes, you are correct. The ears on the B carb, and on the late 31 zenith 3 are thinner and weak. I have a phenolic insulated plate on my B carb, which makes it even easier to break. I tighten (or loosen) in steps to prevent a repeat of breaking one off.

[john charlton]

The Ford plant at Dagenham (England) built AA trucks into 1936 . These were factory fitted with the fully counterweighted B engine and the B carb . Ford ground a 45 degree slice out of the carb intake as without this cut out the carb inlet fouled the RHD steering box . I know you would be very reluctant to take a slice out of yours but Henry did it !!! As an aside some early Dagenham trucks were fitted with the A RHD inlet manifold as these retained the manual advance/retard so Ford happily married a mismatched inlet tract as the A manifold was not drilled out to match the B carb so there was a 1/16" "step" where they met .I have this setup on a RHD cabriolet and it runs like a clock . There is no real need to match the bore as the throttle butterfly is far more of an obstruction than the "step" and I think it adds more mixing turbulence .Cut model B carbs show up here I will see If I can find a pic .

John in festive Suffolk County England .

[Synchro909]

Originally Posted by john charlton

The Ford plant at Dagenham (England) built AA trucks into 1936 . These were factory fitted with the fully counterweighted B engine and the B carb . Ford ground a 45 degree slice out of the carb intake as without this cut out the carb inlet fouled the RHD steering box . I know you would be very reluctant to take a slice out of yours but Henry did it !!! As an aside some early Dagenham trucks were fitted with the A RHD inlet manifold as these retained the manual advance/retard so Ford happily married a mismatched inlet tract as the A manifold was not drilled out to match the B carb so there was a 1/16" "step" where they met .I have this setup on a RHD cabriolet and it runs like a clock . There is no real need to match the bore as the throttle butterfly is far more of an obstruction than the "step" and I think it adds more mixing turbulence .Cut model B carbs show up here I will see If I can find a pic .

John in festive Suffolk County England .

Thanks John. That all goes to confirm what I have said many times about Ford making a hash of the design of these cars. If he intended selling them in RHD countries (and he did), then why didn't he sort out some of this simple stuff????