How a Model A Engine Breathes.........

31 Model A

31 Model A

Well-known member
is an article in the recent Model A Restorer. Although I read the article and some parts twice, most of what was said can only be understood by everyone but me. The one thing I did notice was, in all the diagrams and photos, there was NO maze filter attached. I took Sarah's off some time ago.
 
Before my father-in-law gave me Sister he always ran it with a filter, when I put on the new carb I took it off.....I feel like she runs a lot better without it.
 
Cars will definitely breath without the maze, however, I hate the thought of a fire destroying my car (saw one destroyed just recently). I put a wire mesh in the 180 deg. Version and it runs fine.
 
A very well known carb builder as me if I was going to run an air cleaner. I said yes and he said the carb would run rich without the carb being compensated for the air cleaner. Makes sense to me.
 
1930marie said:
Cars will definitely breath without the maze, however, I hate the thought of a fire destroying my car (saw one destroyed just recently). I put a wire mesh in the 180 deg. Version and it runs fine.
Click to expand...

Then do run an Air Maze if you want to see one catch fire!! :eek: ;)
 
This is the filter I run. It's above the carburetor, so it won't load up with dripping gas. It has a very large filter area so it doesn't richen the air/fuel mixture. Doesn't look like a 1930's accessory, but it works!!!!!!!!
 

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captndan said:
A very well known carb builder as me if I was going to run an air cleaner. I said yes and he said the carb would run rich without the carb being compensated for the air cleaner. Makes sense to me.
Click to expand...
When I bought Sarah, she had a Maze on and it was soaked with gas. I took it off, fixed the GAV linkage and it stopped. Bought a new Maze, had it on for dust and rock prevention and then I took it off again and I'm sure Larry, when re-adjusting the carb will do so with the air intake as it is with the Maze off. As for dust and rock prevention ....I'll just have to deal with it. It ran better when I had it off the first time. Running a bit rich, maybe so...............don't know, she needed a lot done.
 
None of the filters available from suppliers are worth anything here - they won't fit. I make my own with a fitting I make that comes out between the steering column and the choke rod, then points upwards to where I have a 12" filter mounted on the radiator stays. It works a treat with no detectable restriction and no dust in the motor. It's much easier again with a down draft though.
 
WELL, with a good air filter, Vermin will be runnin' STRONG, well after you NO AIR FILTER fans have piston rings that look like THIN snap rings & cylinders that are FUNNEL shaped--LOL
Bill Smart
 
BILL WILLIAMSON said:
WELL, with a good air filter, Vermin will be runnin' STRONG, well after you NO AIR FILTER fans have piston rings that look like THIN snap rings & cylinders that are FUNNEL shaped--LOL
Bill Smart
Click to expand...
Bill, it seems the Maze filter is one of things that it's, "damned if you do and damned if you don't"!!!! which is rather daunting for some who depend upon other's experience to do the right thing. Larry is putting on engine pans so that should help with any anxiety of rocks or debris being sucked in but.....you've mentioned snap rings and cylinders now!!!!! :confused: I'm glad I'm already bald!!!
 
Question from a newbie....

So there seems to be two schools of thought on wether or not an air filter should be used and how the car runs with or without it....based on my limited rsearch on the subject, it seems to me that more do not use a filter than do. It also appears to me that the biggest risk, and I may be wrong here (risk of fire) of not usi a filter is crap getting sucked into the carb....in that case would it make sense to have something that just covers the intake, maybe something as simple as a screen that is clamped on.

Again please keep in mind that before I got my "A" about the most I ever did on a car engine is add windshield washer fluid, so I may be way off base here.

Nick
 
ALL MODERN CARS HAVE AIR FILTERS, even vacuum cleaners. Do you put on a mask when you paint or mow the lawn or pick up Dog turds?-----------
Bill W.
 
BILL WILLIAMSON said:
Do you put on a mask when you paint or mow the lawn or pick up Dog turds?-----------
Bill W.
Click to expand...

NO!!! and modern cars come with Air Filters...Model As did not from what I've been told. Why was it an aftermarket item? Why didn't Henry put them on if they were so important? He did put together one outstanding automobile. I can't see him not putting one on every engine that came off the line if they were so important.
 
BILL WILLIAMSON said:
WELL, with a good air filter, Vermin will be runnin' STRONG, well after you NO AIR FILTER fans have piston rings that look like THIN snap rings & cylinders that are FUNNEL shaped--LOL
Bill Smart
Click to expand...

God knows how this pains me, but I am with Bill on this. Where I live and drive dusty gravel and sand roads are the rule not the exception. Without a filter, engines would last no time at all. Carbs can be adjusted to compensate for the minimal effects of a maze filter.

BTW I find no difference in performance with or without the filter, but I live at about 2,800 feet above sea level which I have found to be on the ragged edge of high altitude settings.
 
31 Model A said:
NO!!! and modern cars come with Air Filters...Model As did not from what I've been told. Why was it an aftermarket item? Why didn't Henry put them on if they were so important? He did put together one outstanding automobile. I can't see him not putting one on every engine that came off the line if they were so important.
Click to expand...

Cost?
 
Even my $89 push lawn mower has a air filter. Twenty eight years ago I adapted a air maze set up to accommodate a larger filter that in no way restricts air intake and I am glad I did so. I cannot imagine what the rings and cylinder walls on my fresh 1988 rebuild would look like today with all the dusty roads I have driven down over the years. Just because Henry did not think them necessary at the time, is a ludicrous idea today.
 
A cynic might say, Henry was in the auto parts business, he sold you a car cheap so you could buy parts from him and he cold make a profit.

Having no filter sure sells a lot of rebuilt exchange engines....i.e you buy a new one and give him back the one you bought before, so he can get it ready to sell back to you later on.
 
Synchro909 said:
None of the filters available from suppliers are worth anything here - they won't fit. I make my own with a fitting I make that comes out between the steering column and the choke rod, then points upwards to where I have a 12" filter mounted on the radiator stays. It works a treat with no detectable restriction and no dust in the motor. It's much easier again with a down draft though.
Click to expand...

Synchro, could you post a pic and explanation of how your fitting is made please. I had a large paper air filter (41/2 inch diam. 6 inches long) horizontally below my Model B carb on my 1930 roadster with 7 tooth box. But since I fitted a 2 tooth Gemmer as replacement, the extra thickness of the lower column clamp means there is only 5 mm gap between clamp and air intake. Not enough to get my old copper air cleaner double-elbow fitting in.
B carb O/D at the air inlet is 2.06 inches. Inlet area is 1960 sq mm (3 Sq in). An A zenith fits in OK. But I run B's on both our cars for better top end power, no stalling on stops, still with excellent economy. Our gravel roads are very dusty too.
Any advice on how you made yours greatly appreciated.
SAJ in NZ
 
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