Carb float valve

[Lightman7]

Originally Posted by old ugly

Lightman7

a few things i have found.

<snip>
-on the top of the float where the needle rests <snip>

The float is new, so no divots and not bent, as much as I'm tempted to. I'll check the washer seat area - but I'm hesitant to over tighten as I don't want to strip the cast iron threads.

[[email protected]]

FYI. When I first started driving my Model A many years ago my local club experts warned me to not use the Grose Jet type of ball float valves. Their reasoning was simply based upon their own experiences. They all told me that it would limit your top end by not supplying the same fuel flow as the original Henry float valves.

I have always used the Henry valve that has been honed into the seat to make a leakless seal. Lots of miles over the years with no issues or leaks. Lots of top end smooth running speed using Zeniths, B Carb, Tillys, and Marvel Scheblers with this same float valve setup.

[old ugly]

Originally Posted by Lightman7

The float is new, so no divots and not bent, as much as I'm tempted to. I'll check the washer seat area - but I'm hesitant to over tighten as I don't want to strip the cast iron threads.

ok
have you tried this?
this will allow you to see if the float is moving freely up and down, it only takes the slightest hang-up to screw things up.
a clear drinking glass works good too. make sure its big enough to clear everything.

[old ugly]

Originally Posted by Lightman7

I'm not sure that this would solve my problem, as the fuel overflows, so I know something is leaking inside. I would REALLY like to know if you use permatex on the spacing washers or not.

did you solve the problem?

[Gene F]

Originally Posted by [email protected]

FYI. When I first started driving my Model A many years ago my local club experts warned me to not use the Grose Jet type of ball float valves. Their reasoning was simply based upon their own experiences. They all told me that it would limit your top end by not supplying the same fuel flow as the original Henry float valves.

I have always used the Henry valve that has been honed into the seat to make a leakless seal. Lots of miles over the years with no issues or leaks. Lots of top end smooth running speed using Zeniths, B Carb, Tillys, and Marvel Scheblers with this same float valve setup.

I did not know that about the top-end. Good info.

[Ed in Maine]

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I rebuild carburetors as a service for my club. I always tell the recipient that the weak link in the carburetor rebulld is the gas shutoff valve. I try to use the old valve, soaking it overnight and flushing it out. After cleaning, I gently tap the valve into the seat with my fingers to obtain good contact with the seat. Sometimes I will cut a piece of cloth about 3/16 in. wide and stuff it into the valve inlet, soak it with carb cleaner and rotate the valve stem into the rag to wipe the seat off. After that, if it still leaks, it is time for a new valve.

With regard to the 5/8 in. float level, Steve Pargeter has stated in his repair manual that a bit lower may give you more tolerance before the carb leaks. You only have to keep the gas level over the Compensator Jet to obtain good performance at all times. If you set your level down 5/8 in., and then look into the throat of the carburetor, you will see the gas shimmering at the top of the jets. Your carburetor may not be leaking but you may smell gas in your garage the next morning. I prefer 11/16 in. down from the top of the lower casting, but definitely less than 3/4 in. You will know you went too low with your level if your car is stalling at stop signs. The gas is coming away from the Compensator Jet.

Another reason to use a 11/16 in. float level dimension is that the float valve has to have a "seat load". The valve can't just touch the seat but must push into the seat with enough force to achieve a tight shut off. This force comes from the gas level rising around the float. This is one of the advantages of viton soft seat because it requires less force to achieve a tight shutoff than the metal to metal seat. As you might surmise, I worked for control valve company for twenty years and achieving a tight shut off for a boiler fuel regulating valve was very important. Ed

[katy]

Originally Posted by Ed in Maine

With regard to the 5/8 in. float level, Steve Pargeter has stated in his repair manual that a bit lower may give you more tolerance before the carb leaks. You only have to keep the gas level over the Compensator Jet to obtain good performance at all times. If you set your level down 5/8 in., and then look into the throat of the carburetor, you will see the gas shimmering at the top of the jets. Your carburetor may not be leaking but you may smell gas in your garage the next morning. I prefer 11/16 in. down from the top of the lower casting, but definitely less than 3/4 in. You will know you went too low with your level if your car is stalling at stop signs. The gas is coming away from the Compensator Jet.

Another reason to use a 11/16 in. float level dimension is that the float valve has to have a "seat load". The valve can't just touch the seat but must push into the seat with enough force to achieve a tight shut off. This force comes from the gas level rising around the float. This is one of the advantages of viton soft seat because it requires less force to achieve a tight shutoff than the metal to metal seat. As you might surmise, I worked for control valve company for twenty years and achieving a tight shut off for a boiler fuel regulating valve was very important. Ed

Thanks for the insight.

[Gene F]

Originally Posted by Ed in Maine

I rebuild carburetors as a service for my club. I always tell the recipient that the weak link in the carburetor rebulld is the gas shutoff valve. I try to use the old valve, soaking it overnight and flushing it out. After cleaning, I gently tap the valve into the seat with my fingers to obtain good contact with the seat. Sometimes I will cut a piece of cloth about 3/16 in. wide and stuff it into the valve inlet, soak it with carb cleaner and rotate the valve stem into the rag to wipe the seat off. After that, if it still leaks, it is time for a new valve.

With regard to the 5/8 in. float level, Steve Pargeter has stated in his repair manual that a bit lower may give you more tolerance before the carb leaks. You only have to keep the gas level over the Compensator Jet to obtain good performance at all times. If you set your level down 5/8 in., and then look into the throat of the carburetor, you will see the gas shimmering at the top of the jets. Your carburetor may not be leaking but you may smell gas in your garage the next morning. I prefer 11/16 in. down from the top of the lower casting, but definitely less than 3/4 in. You will know you went too low with your level if your car is stalling at stop signs. The gas is coming away from the Compensator Jet.

Another reason to use a 11/16 in. float level dimension is that the float valve has to have a "seat load". The valve can't just touch the seat but must push into the seat with enough force to achieve a tight shut off. This force comes from the gas level rising around the float. This is one of the advantages of viton soft seat because it requires less force to achieve a tight shutoff than the metal to metal seat. As you might surmise, I worked for control valve company for twenty years and achieving a tight shut off for a boiler fuel regulating valve was very important. Ed

OK, 11/16 fuel level with the car idleing, or 11/16 float level?