How is it.........

[Licensed to kill]

.....that these cars don't run an air filter????. Why don't they get dusted? Any modern car would be pooched in pretty short order running with out an air filter and we have mostly paved roads. How is it that these model A's could run around on dirt roads with no filter back in the day??.

[Chuck Sea/Tac]

What makes you think they didn’t have failures?
Wore out rings and cylinders, poor quality oil and bearing wear.
I’m sure someone will have some facts regarding longevity.

[redmodelt]

Babbitt bearings, run at lower RPM's and oil changed often(er).

[Johnny Nitro]

As Jay Leno likes to say...”The air was cleaner back then”

[fundytides]

Don't have specific facts but many cars back in the 40's and 50's were worn out in 40,000 miles. I played with flat head Fords in the 50's and most of them had motors rebuilt one or more times by the time they were 5 or 6 years old or were smoking so bad you had to run a breather pipe from the oil filler down under the car, and these cars had air cleaners (oil bath) and sometimes oil filters. "Smokers" were a fact of life, especially if you lived on a hill and liked to watch the cars go by. Going by this, I would think cars of the 20's and 30's, often without air cleaners or oil filters had an even shorter usable life span. The saving grace was that most cars were not driven a great number of miles and were often only driven seasonally in more northern climates. I know that my grandfather only drove his cars from April to October and then only on weekends. He walked to work. His 53 Ford only had about 12,000 miles on it when it was 10 years old and a grandson took it for a drive and broke a piston. I think, in spite of ourselves we should be impresses with the quality and reliability of modern cars.

[rotorwrench]

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Engine overhauls and partial overhauls were far less expensive than the purchase of a new car and much of it could be done without removal of the engine in some cases. Air filters came in with the V8 and aftermarket filters were available for the folks that knew it was a good idea.

[Licensed to kill]

I get that these cars required overhauls more often. It seems to the that i read somewhere that 5000 miles was about it but I had a clamp break on my peterbilt a couple years ago that allowed the intake plumbing to shift a bit causing an intake leak between the air cleaners and turbos and in what I'm estimating to be around 500KM (half of that gravel) the engine was dusted to the point that when we informed it, there was about a .010 ridge in the liners, the cam and half the lifters was shot and the blowby was horrendous. Granted these little skinny tires don't kick up much dust but still.

[The Master Cylinder]

But, but an air filter will make it run rich... say the naysayers.

[GerryAllen]

Not being cheeky, if the air filter makes it run rich would one not lean the carb out or am I wrong. Relatively new to Model A's so don't have the answers, just a lot of questions

[30 Closed Cab PU]

Leaning the carb out would probably involve a complete tuning of the carb, including re-jetting.



Another supposed thing you can do is to perform or have the carb air balanced which involves modifying the carb. Some say this works, some say it does not work



Others report good results with using a properly sized/high air flow filter such as a K and N. Detractors of this method say that these filters do not do a proper job filtering allowing some particulates through which still causes engine wear.


If you do a search here on the Barn on Air filters there is tons of discussion about air filters, with no general agreement on their use.

[johnneilson]

This is a good question, the answer is progress, lessons learned.

Oil filters didn't get much attention until much later, especially full flow filter systems and pressure fed bearings.

John

[mhsprecher]

The publications on carbs talk about how an air filter makes them run rich. Both of my cars came with AirMaze filters which I removed and replaced with a K&N Highboy. They seem to run fine, but maybe a little rich.

Logically the air balancing makes sense. I know that Renner's Corner will modify your carb so you can run a filter. I have not tried it, but I might at some point to see what difference it makes.

[77Birdman]

Originally Posted by fundytides

Don't have specific facts but many cars back in the 40's and 50's were worn out in 40,000 miles

Originally Posted by fundytides

. I played with flat head Fords in the 50's and most of them had motors rebuilt one or more times by the time they were 5 or 6 years old or were smoking so bad you had to run a breather pipe from the oil filler down under the car, and these cars had air cleaners (oil bath) and sometimes oil filters. "Smokers" were a fact of life, especially if you lived on a hill and liked to watch the cars go by. Going by this, I would think cars of the 20's and 30's, often without air cleaners or oil filters had an even shorter usable life span. The saving grace was that most cars were not driven a great number of miles and were often only driven seasonally in more northern climates. I know that my grandfather only drove his cars from April to October and then only on weekends. He walked to work. His 53 Ford only had about 12,000 miles on it when it was 10 years old and a grandson took it for a drive and broke a piston. I think, in spite of ourselves we should be impresses with the quality and reliability of modern cars.

Even up to recently. I started driving in 1980, and even then once a new car got to 50k it was traded. I think the life of a car then was about 100k, now 100k and theyre just getting broken in!

[Licensed to kill]

Perhaps I'm misunderstanding how these things work but to my way of thinking, these are among the EASIEST engines to adjust for any "rich" condition that may occur from adding an air filter, just turn the GAV back a bit. I suppose for those whose cars run best with the GAV only open 1/4 turn or less you may run out of adjustment before you reach proper air/fuel ratio, in my case, my car needs 1 full turn of the GAV to remedy a lean condition so I can just turn my GAV back a bit if an air filter causes a rich condition. Also, to my way of thinking, if there is NOT enough adjustment available in the GAV to get the proper mixture with an air filter, I'm thinking that rejetting the carb is a much better/cheaper/faster option than dusting the motor.

[30 Closed Cab PU]

I could be incorrect, the GAV does very little for idle, if idle rpm is set to less than 500 rpm. I believe at cruising speeds the GAV also does not do much.



At idle and cruising speeds mixture is set/controlled by different Jets in the carb.


Please correct me if my understanding is wrong.