Air Filter or not

joe.manfre@me.com

joe.manfre@me.com

Junior Member
I recently added an air filter from Snyders or Bratons, can't remember.
The air filter is made to fit works well and has a metal element.
I have been told that an air filter of any kind is too restrictive and can make the engine run too rich.
The carburetor (Zenith) is not designed to have the restriction this air filter brings. Even a metal filter.

Is this a true fact?
 
Anything put into the carburetor's air intake stream reduces intake CFM and engine performance. Paper & foam filters restrict much more than metal screens such as the Air Maze. To many "A" drivers, the decrease in performance is not obvious, but engine power, gas mileage and dirty spark plugs happen.
If an "A" is driven on unpaved roads or through farm fields, then an air filter has value, but the engine should be tuned to accommodate the reduce air breathing. I would lean the fuel mix, run a hotter spark plug and iterate the changes until the plugs are running gray - tan.
 
I run air filters on every car that I care about. Have never experienced the richening condition that Fordbarn preaches as fact. If the air filter starts to get clogged, then it will begin to run a little fat, but you can tell, and you know it's time to clean the air filter. Then when you do, notice all the dirt and crud that comes off and thank yourself that it wasn't ingested by your motor.
 
The screen original air maize filter hasn’t made a mixture difference on my car, was checked for changes up to 3200 rpm, and it is good at snuffing the flames of a backfire, freshly dipped in oil it drips some, probably the k&n oil would be good too
 
https://fordbarn.com/forum/showthread.php?t=108264

Keep a fire extinguisher onboard with you if you do run one (you should have one regardless). I had one of the mesh wire filters on mine. After a no-start condition one day after work, I popped the hood and noticed gasoline dripping out of the filter. Took it off, waited 10 minutes and it fired right up with no choke (cold start). It was parked on a slight incline and I didn't shut the fuel valve off and run the bowl dry. I just parked, turned the car off, and shut the fuel valve off.

As far as taking the air filter off a modern car, no I wouldn't. The system was designed to run with an air filter from the factory. These cars weren't and putting a paper filter below the carburetor is a fire hazard.
 
My '28 came to me with a baffle of sorts over the carb opening. No air filter. Would even that restrict airflow enough to be noticeable?
 
An air filter that really filters the air will reduce wear in any engine. Carburetors that are designed to use an air filter will have the vent to the float bowl routed to just in front of the choke so that any restriction in air flow does not enrichen the mixture. If you want to add a real air filter to your Zenith then modify it to vent the float bowl to just in front of the choke. Plans for doing this have been published on the Barn.

A lot of race cars do not use air filters because they lower the amount of air the engine can suck in. However, these engines get rebuilt often and are not driven daily.
 
I wouldn't recommend one of those little baby filters the vendors sell. Get the biggest K&N that will fit. Never an issue on my Town Sedan.

527651
 

Attachments

  • IMG_3349.jpg
    IMG_3349.jpg
    54.7 KB · Views: 344
Y-Blockhead

I have a marvel carburetor also and like your setup. Could share the part numbers for the hose and air filter. Thanks
 
ModelAArmy said:
Y-Blockhead

I have a marvel carburetor also and like your setup. Could share the part numbers for the hose and air filter. Thanks
Click to expand...

Tom, the air filter is K&N E-9257, https://www.amazon.com/9257-High-Performance-Replacement-Filter/dp/B000E7DMKE/?tag=atomicindus08-20. the "base" is part of an old Air Maze, the "hose" is a 2" PCV elbow modified to fit the Marvel Carb.

You could possibly use the elbow from the Air Maze but it is held on with a screw. I did not like that option as the marvel carbs are soft zinc alloy. So I used the PCV and hose clamps.
 
To find out how your carb is jetted is a very simple. It can be done by yourself if you are up to it. Any tune up shop should be able also.
Put a portable air/fuel analyzer probe in the tail pipe. Go drive the car under ALL of the varying conditions and record the readings for all the situations. This will tell you how to re-jet the carb.
While tailpipe analyzers are not the most accurate, they will do for average street driving.

For long engine life, some type of air cleaner should be run.
 
I would no sooner run without an air filter than fly. Within the last month (late winter), I did a 2,000 miles run in the outback. Conditions were not very dusty compared to what I have seen in summer but after that distance, I cleaned nearly an egg cup full of dust out of the filter. That is an enormous amount of dirt that didn't grind away at the internals of the engine. It is no wonder the average time between engine rebuilds on Model As in the day was so short.
Run a filter or not - it's your choice but if you decide no, be prepared to rebuild he engine more often.
 
Y-Blockhead
Thanks for the info but I have questions
Is the 2” pvc hard or is it soft. The only pvc I know is schedule 40
How do you secure the filter to the pipe.
Sorry to bother you but I would like to do it exactly like your setup
Thanks
 
I run a K & N filter and never looked back. I don't care what they did
80 years ago, this is the only way to extend your motor's life. You would have to put a
gun to my head to get it off. Sorry, it's 2023.
 
ModelAArmy said:
Y-Blockhead
Thanks for the info but I have questions
Is the 2” pvc hard or is it soft. The only pvc I know is schedule 40
How do you secure the filter to the pipe.
Sorry to bother you but I would like to do it exactly like your setup
Thanks
Click to expand...

No problem Tom Yes the PCV is hard. It is painted flat black.

You need these parts from an old Air Maze. I got mine off e-bay for ~$5.
527667


The PCV fits on the bottom of the Air Maze and is held on by 2 screws. You will have to extend the center bold as the K&N is much longer that the Air Maze.

On the Marvel end, you will have to open up the PCV to fit the Marvel air horn. Also modify it to fit around the choke.. I cut two slots in the PVC so I could tighten the clamp around the carb.

I hope some of that helps? PM me if you want with questions.
 

Attachments

  • Air Maze.jpg
    Air Maze.jpg
    10.9 KB · Views: 317
You must log in or register to reply here.
Back
Top