Dual element filtration. How much dust gets past? Yup…

[dirttoys]

To me this argument doesn't hold water. The filter is already designed to compensate for being partially plugged. IE it has extra capacity. Also by far the majority of tractors on TBN are rarely used at full power. Mine sees full power in spring when I'm rototilling gardens. The rest of the year is pretty easy going.

LOL I love these threads!! While the filter is designed to function safely with some dirt in it, it is also designed to work safely brand new, or clean.

If not compensated for, reduced air flow; reduces power, increases fuel consumption, and adds extra pollution

Best,

ed

 

[Jerry/MT]

I don't recall saying anything abut a heavy dust accumulation ever. That's a totally different conversation as far as I'm concerned. Your missing my point and that's ok.

"Most people seem to think that they are doing their engines a favor by keeping the filter clean. A service manager once told me that the dirtier the filter the cleaner the air going into the engine. It makes sense when you think about it. So why would you give your engine the dirtiest air possible by cleaning the filter?

Isn't this your quote? Maybe you can explain what I'm missing.

 

[DK35vince]

Servicing Your Air Filter – to Change or Not to Change? │Donaldson Engine & Vehicle

While new Donaldson air filters provide good engine protection, a Donaldson air filter that has been in service for a period of time works even better than a new one.

www.donaldson.com

 

[MHarryE]

Inner element is safety element. You can tell by its size it has little capability before becoming plugged. Need to follow the book on the main filter as they can be different designs. Three of mine have filter indicators - practically useless. I noticed my largest th tractor was down on power after doing a custom job for a farmer with particularly dusty reclaimed land. Tractor, 175hp model, was noticeably down on power at the end but restriction indicator showed still good. As this tractor has a very expensive filter, I followed the book instructions on cleaning and got my power back. Will install new one this spring at half recommended life but conditions can dictate.

 

[ovrszd]

Inner element is safety element. You can tell by its size it has little capability before becoming plugged. Need to follow the book on the main filter as they can be different designs. Three of mine have filter indicators - practically useless. I noticed my largest th tractor was down on power after doing a custom job for a farmer with particularly dusty reclaimed land. Tractor, 175hp model, was noticeably down on power at the end but restriction indicator showed still good. As this tractor has a very expensive filter, I followed the book instructions on cleaning and got my power back. Will install new one this spring at half recommended life but conditions can dictate.

Excellent post.

 

[pmsmechanic]

"Most people seem to think that they are doing their engines a favor by keeping the filter clean. A service manager once told me that the dirtier the filter the cleaner the air going into the engine. It makes sense when you think about it. So why would you give your engine the dirtiest air possible by cleaning the filter?

Isn't this your quote? Maybe you can explain what I'm missing.

Ok I thought I had spent enough time trying to write what I meant but I'll take another stab at it. My point is that dirt will plug the largest "holes" in the filter first because that is where the higher air velocity is. Therefor the air going into the engine is cleaner. Obviously there comes a point of diminishing returns and you have to clean your filter. I didn't think that I had to mention that because I thought that fact was pretty obvious.

 

[ovrszd]

The most important thing to me is velocity at the filter element. The dirtier the filter the higher the velocity thru the portion that still allows air transfer. The faster the velocity the less effective the filter element can be.

By design the intent is to dramatically slow the velocity in the filter housing. For example you might have a 3" diameter tube feeding the filter element cannister. A cannister that might be 12" in diameter and 14" long. Inside is an element 8" in diameter and 12" long, pleated. This allows the velocity to drop when going thru the filter element. Critically important.

Here's an excellent article talking about air movement required to support engines of various sizes. A very nice "calculator" included.

If you know the CFM capacity of your filter element when clean, you can figure out pretty quick how dirty it can get before causing power loss.

Air Flow (CFM) | Widman International SRL

www.widman.biz