Carter AFB Secondary auxiliary valve assembly

[Hyper_pak]

I had a conversation a few years back about AFB carbs and the "Auxiliary Valve Assembly"
Some call it a flap.
Anyway a statement was made that all AFB carbs had the Aux Valve.
Not true.
Carbs with secondary boosters facing fore and aft have the Aux Valve.
Carbs with secondary boosters facing right and left do not have the valve.
Any way I am searching for a valve for my 3083S carb.
I tried all the parts I have and nothing fits.

 

[RustyRatRod]

Well I'll be dingle dangied.

 

[Bewy]

Also called the 'Velocity valve'. If it doesn't fit YOUR AFB, then your model was not designed to use the VV. There were a few different VVs, but they all fitted in the carbs that were designed to use a VV. There were 505 different AFB models....

 

[Hyper_pak]

Mine has the machining for the Valve.
It is MIA.

 

[rumblefish360]

But yours is not made to use the velocity air valve. These models I have seen at the 600cfm rating on top of 440’s. It’s been a very long time but IIRC, it was an early 60’s yacht. I can’t remember the model at the moment.

 

[Hyper_pak]

Why would Carter machine the carb body with the saddles that hold the valve if they were not going to be used?

 

[Hyper_pak]

Exploded view: Hard to see numbers but 42 is the flap.

 

[rumblefish360]

Why would Carter machine the carb body with the saddles that hold the valve if they were not going to be used?

I can’t say for sure but when I noticed this on my old friends boat with the 440, I asked how it performed with of course mentioning the lack of the air velocity valve.

He said even in the dead of winter, stone falls start, drop it in drive and nail it, it would burn rubber and take off no problem.
Now do be reminded it was a 600 cfm carb.

Under cfm carburetor? In a way, yes, in a way, no. A luxury ride is just after torque to move its weight and ultimate top end rpm power is not worried about. As long as the boat moves on demand, the customer will be happy.

I can’t say for sure but I think it had a 2.76 ratio.

Anyway, the big engine can handle a wide open throttle from a standstill even in the big car.

 

[Bewy]

If the bottom pic in post #1 is your carb, then it is not designed to take the VV.

 

[66fs]

Can you post pictures of your carb? What do the secondary bores measure? I may have an extra Velocity Valve from a HP 273.

 

[66fs]

Velocity valves were used on HP engines: 440 HP; 273 HP; GTOs; Vettes; etc. They were gone by 1968, replaced by the AVS which had a spring loaded, adjustable Velocity Valve.

 

[Hyper_pak]

If the bottom pic in post #1 is your carb, then it is not designed to take the VV.

No those were just two carbs I took apart.
Here is mine.

 

[Hyper_pak]

Can you post pictures of your carb? What do the secondary bores measure? I may have an extra Velocity Valve from a HP 273.

My secondary bores are 1 9/16, the primary are 1 7/16.
It is the small air horn style. 4.5 inch.
It's called a C4-AFB on this sheet.

 

[66fs]

My secondary bores are 1 9/16, the primary are 1 7/16.
It is the small air horn style. 4.5 inch.
It's called a C4-AFB on this sheet.

Are there numbers on the secondary boosters? Along the leg from the outer ring to the center booster.

 

[Hyper_pak]

 

[66fs]

OK, so it looks like your Hyper Pak AFB is very similar to a HP 273 AFB. 273 Secondary boosters are 222 and 221, Bore sizes are the same, so my guess is that a 273 Velocity Valve will work. I should have a spare, I'll try and find one.

 

[Hyper_pak]

Thanks!

 

[Hyper_pak]

@66fs
Thanks for the Valve, unfortunately it will not fit.
It's close but it's not wide enough.

 

[abdywgn]

Stan, can you file down the nubs that sit on the outside of the throat?

 

[Hyper_pak]

I could......
But this carb is a Virgin Albino Elephant.
How many of those have you seen?
I will keep looking for the correct valve.

 

[abdywgn]

other than yourself. would anyone be able to tell by looking at it? Looking for the correct one is probably a better idea than my butchering. I could see me doing that, getting filings stuck somewhere and have all sorts of problems.

 

[Bewy]

Contact Jon Hardgrove at The Carb Shop, Eldon, Missouri. He will have the correct valve. It is important to get the correct valve as there were many differences, mainly in the weights on the ends. Some valves had the blades horizontal, others the blades are angled. I have a valve that has alum weights on the end.
Obviously these differences will have an effect, hence the need to get the correct valve.

 

[Hyper_pak]

@Bewy
Thanks!
I will give him a shout.