Does (or did) people rotate round air filters

[Donald]

My 93 Suburban with TBI is basically setup like it would be for a carb with a round air filter sitting on top of the TBI. The air coming in is directed towards one section of the filter. When I pull the cover (looking for mouse nests) I rotate the filter maybe 45 degrees as the one section that air was directed at gets dirtier than other sections.

 

[law3500]

That's not only for round filters, both my trucks have factory panel (square) filters and I rotate them because it is obvious by looking at them that they get dirtier in one section and the air/dirt distribution is no where near uniform. I think it's a good practice.

 

[Turk]

OMG - I thought I was the only one who did this within change intervals...

Round, square, rectangle, I bang them out on the cement (so I can see what comes out...)

, rotate & put back in!

Way to go!

 

[Boomer]

And the neat thing with round filters is you can invert the metal cover and bolt it back down, leaving an air space all the way around so you can see the paper filter. Boy, does this sound great when you hit the accelerator. Or at least it did when I was 16 (driving a 62 Chevy 6 cylinder!)

 

[Turk]

Originally Posted By: Boomer
And the neat thing with round filters is you can invert the metal cover and bolt it back down, leaving an air space all the way around so you can see the paper filter. Boy, does this sound great when you hit the accelerator. Or at least it did when I was 16 (driving a 62 Chevy 6 cylinder!)


This was "mandatory" on the 60's & early 70's cars I had....

 

[JHZR2]

yes.

 

[demarpaint]

Yes.

 

[Donald]

My Dad would install a new wiper to the driver side and move the driver to the passenger and toss the old passenger. Of course back then both sides were always the same size. He also installed a foot operated pump and windshield washer kit (probably from JC Whitney). Anyone else have a Dad like that. In addition he mounted a block of wood where the radio might go and installed real mechanical gauges, including one for gas pressure. Imagine bringing gas under pressure in the passenger area.

 

[eljefino]

Originally Posted By: Donald
My Dad would install a new wiper to the driver side and move the driver to the passenger and toss the old passenger. Of course back then both sides were always the same size.


I do that!!! I also "part out" blades so if one has a busted rubber hook holder thing and another has another problem I build one good from two bad. I also do this with clothespins!
Quote:


In addition he mounted a block of wood where the radio might go and installed real mechanical gauges, including one for gas pressure. Imagine bringing gas under pressure in the passenger area.


My dad pulled this off with his ford fairmont. Two gauges in the middle of the dash looked normal, but another two were mounted below the dash in the passenger footwell. Inelegantly. I'd be sitting shotgun, bored as a kid, and start tapping the gauges with my left foot, ever more aggressively until he'd yell at me to knock it off.

He added volts, vacuum, water temp, and amps. Not oil pressure! He burned up a dodge omni, two weeks old, by adding an oil pressure gauge, that the tube got loose and hosed things down with oil.

 

[LargeCarManX2]

There should be a deflector where the air enters via the inlet on or near the filter. When the air hits the deflector it dispurses the air all around the air filter.

 

[4ever4d]

Originally Posted By: LargeCarManX2
There should be a deflector where the air enters via the inlet on or near the filter. When the air hits the deflector it dispurses the air all around the air filter.

I have seen some older vehicles that were built like that,an 79 Ford F100 i had sticks out in my mind,was made like that with a deflestor rounded so that the air would disperse around the filter cannister and catch the entire filter element.

 

[Garak]

That was the norm on a lot of farm equipment. Same deal on my old LTD when it had lots of blow-by fouling up one spot on the air filter.

 

[Chris142]

I have never heard or thought of turning an air filter.

 

[bigmike]

I rotate all of them, including my K&N cone filter.

 

[artificialist]

I learned this by asking the most experienced guys in my automotive class. I asked him "What is the point of having 360 degrees of filtration if only 15 degrees get used?" His answer was "That is so you can rotate the air filter to get more use out of it."

What is really annoying about some old Datsun and Nissan models is that there is a carb or a TBI, however, there are 2 carb studs instead of 1, making filter rotation impossible, despite having an intake system that would normally allow it.

This might have applied to other carb or TBI engines not made in the USA, but the Nissan ones are the first that come to my mind.

 

[Loobed]

I did that with my first car but now I wont do it. My thought is that dirt gets caked on one area and plugs the filter, and if I rotate it, dirt will get caked on another area reducing the amount of filter area.

 

[doitmyself]

In my opinion, I cannot see that rotating the filter would have any real, measurable effect. A new filter starts out with equal negative pressure on the inside filter media, around the whole circumference, 360 degrees. The air goes through the filter at the least restrictive area. As that area start to clog, the air then moves to the next least restrictive area.

Are you guys suggesting that if the air has to move a few inches left and right, that there will be a noticeable HP or other performance loss.....in a daily driver? If so, please explain.

There is also the other camp (drilled into me regarding ag. equipment). The less you mess with your filter, the less chance of directly introducing dirt into your engine. Either by careless "knocking it on the concrete" or faulty reinstallation creating a bad seal. Or, physically damaging the paper or seal.

Just my thoughts.

 

[TC]

"In my opinion, I cannot see that rotating the filter would have any real, measurable effect...The air goes through the filter at the least restrictive area. As that area starts to clog, the air then moves to the next least restrictive area." Yes, I was thinking the exact same thing. It may not matter if you rotate or not. That said, if one is getting water spray, snow or salt spray, oily soot, or other random debris my squirrel brain can think of that may potentially compromise the media in some way, then rotating the filter would help spread that impact all around the media, and not concentrate it in one (weakened) spot until you’re ready to change it out.

“Round, square, rectangle, I bang them out on the cement (so I can see what comes out...), rotate & put back in!” Personally I’ve never been a big fan of that. Air filters aren’t particularly fragile, but they’re not built out of granite slabs either. I’ve never banged a $20 air filter on anything….by choice. I even pay close attention to not inadvertently crimping or cutting the paper pleats when closing an air box….the antithesis of “banging.”

 

[Shannow]

S.O.P on old Holdens with the A24 Ryco filter,

The trumpet would direct the air at a section of filter, and you would see an oval of dirt (*), you'd bang it, and rotate the filter out of the dirt.

As you advanced, you drilled out the spot rivets on the air filter housing, and made a great big post slot for the air to get in.

In hindsight, as the filter loaded, the air would move around the housing to a clean bit, but there's still a tiny tiny bit more DP then.

(*) having moved out to the bush, my air cleaners have never been cleaner...I'm suspecting that they got so filled with muck in the 80s and 90s when I was mostly in the city is soot, lead oxides, and rubber dust. The dust was certainly a lot darker than the stuff I deal with these days.

 

[edwardh1]

Originally Posted By: LargeCarManX2
There should be a deflector where the air enters via the inlet on or near the filter. When the air hits the deflector it dispurses the air all around the air filter.

true