Thread: K&N air filter

Brian, some of those cartridge type oil by-pass systems actually work

Personally I'd prefer to use Mann's centrifuge by-pass system, as used in the TD5.

Originally Posted by Brian Hjelm

If you are interested in filtration, there is only one brand, Donaldson. Why do you think all those OEM truck and mining equipment manufacturers use nothing else.

Actually there are 3 brands you will find OEM on mining and industrial equipment:
Donaldson
Mann + Hummel (Mann Filter)
Fleetguard (now Cummings Filtration)

All 3 make good quality products, which will help your engine to live longer. There are some good smaller companies out there, but they usually don't have the money for good R&D, so just copy what the "big 3" are doing (usually a few steps behind).

As Rick said above, bypass filters or centrifuges do work. If anyone is interested I can dig out some graphs of the soot/particulate content of engine oil with and without a bypass centrifuge.

Originally Posted by rick130

Brian, some of those cartridge type oil by-pass systems actually work

Personally I'd prefer to use Mann's centrifuge by-pass system, as used in the TD5.

Yes, they do. We used to put them on all trucks made at White Motor Corporation. The toilet paper ones don't work. Detroit Diesel, by the way, considered a bypass filter superfluous, bu allowed their use. If you have an adequate full-flow filter there is really no need for a by-pass filter as clean oil only is going through to the working parts.

Originally Posted by isuzurover

Actually there are 3 brands you will find OEM on mining and industrial equipment:
Donaldson
Mann + Hummel (Mann Filter)
Fleetguard (now Cummings Filtration)

All 3 make good quality products, which will help your engine to live longer. There are some good smaller companies out there, but they usually don't have the money for good R&D, so just copy what the "big 3" are doing (usually a few steps behind).

As Rick said above, bypass filters or centrifuges do work. If anyone is interested I can dig out some graphs of the soot/particulate content of engine oil with and without a bypass centrifuge.

Fleetguard was originally a Cummins after-market line selling non-original replacements for Donaldson parts. My experience with Mann has been purely as a replacement parts item. As a matter of interest, Donaldson used to make ( maybe still do) all Caterpillar branded filters. Duralife outlets couldn't sell them under the Donaldson name unless the local Caterpillar distributor gave approval. Waugh & Josephson (NSW) gave approval, Hastings Deering (Qld) didn't. Interestingly Donaldson once used to sell a special washing fluid for their air cleaner elements, but stopped, and then recommended against washing. There are now indpendent businesses providing this service, particularly to the mining industry. Utah used to buy filters by the truckload when I was in the mining & construction equipment business, so obviously washing will save these operations lots of Oxfords.

Originally Posted by british4wd

We have a customer with a 300 Tdi Disco that has a K& N filter fitted. This vehicle goes on very little dirt roads but every time we see it the filter is covered in a thick layer of sludge, how the engine breathes through it is a mystery. We just put a correct apaper one in and pop the KN into the box and put it in the back of his Disco.
Okay for race vehicles and not much else.

Alan

Doesn't this show that the filter is working trapping everything or close to it? K&N say that they start to filter better when at this point.

Originally Posted by Brian Hjelm

If you have an adequate full-flow filter there is really no need for a by-pass filter as clean oil only is going through to the working parts.

Sorry but this is completely incorrect. Full-flow filters, due to their need for low-pressure drop full-flow operation and long life, generally have only a 50% removal efficiency at 5 microns. It has been proven that soot and other small particles which are much smaller than 5µm can cause SIGNIFICANT ENGINE WEAR, and these can ONLY BE REMOVED by a BYPASS FILTER/CENTRIFUGE.

I have dealt with a lot of engine manufacturers, and I have been surprised by their lack of knowledge when it comes to filtration - most of them rely on companies like donaldson and mann+hummel for this. So I wouldn't put much store in the "official" position of detroit when it comes to bypass filters. I think your knowledge may also be slightly out of date - in the future almost all diesels will have bypass centrifuges fitted.

Originally Posted by Brian Hjelm

Fleetguard was originally a Cummins after-market line selling non-original replacements for Donaldson parts. My experience with Mann has been purely as a replacement parts item. As a matter of interest, Donaldson used to make ( maybe still do) all Caterpillar branded filters. Duralife outlets couldn't sell them under the Donaldson name unless the local Caterpillar distributor gave approval. Waugh & Josephson (NSW) gave approval, Hastings Deering (Qld) didn't. Interestingly Donaldson once used to sell a special washing fluid for their air cleaner elements, but stopped, and then recommended against washing. There are now indpendent businesses providing this service, particularly to the mining industry. Utah used to buy filters by the truckload when I was in the mining & construction equipment business, so obviously washing will save these operations lots of Oxfords.

Fleetgard have moved on since those days and now have their own R&D facility, and are responsible for all OEM on Cummings engines, and many others. Donaldson still make the OEM filters for all cat engines. Mann Filter have most of the European OEM market, as well as a significant proportion in other parts of the world. AFAIK they are now equivalent to Donaldson in market share.

Sorry for the hijack but as it came up (as predictably it would)

Originally Posted by Stevo_62

... and most important of all clean your paper element once every 5000k when u change your oil and filter

There is a theory that a new paper filter is less efficient than one that has accumulated a little dust. In other words a new filter used on a dusty road will let the finer particles through.

I check mine every 5000 kms and make a call as to whether I change it or not.

Any views?

Originally Posted by QSDT

Doesn't this show that the filter is working trapping everything or close to it? K&N say that they start to filter better when at this point.

K&N filters usually have a much smaller surface area to collect particles than the OEM filter, so just looking at how much dust is on a filter isn't a good method of assessing how a filter works. Also, big particles represent most of the mass/volume of dust getting to the filter, whereas small particles are present in much higher numbers, so lots of smaller particles may be getting through the filter and causing engine wear, even though it looks like a lot of particles have been trapped by the filter.