Yeah, I've been so busy devoting my bashing abilities to other things that I haven't dedicated much time to 6637 bashing. Only so many hours in a day.

 

My intended point was that a truck can breathe air that meets the EPA clean air standards and still be ingesting many small um particles that do engine damage but are too small to be seen with the naked eye. In such a case the intake tube will test "clean" by visual inspection with or without a filter installed!

If there's no CCV mod you'll have some oil coating the inside of the intake tube, and even with a CCV mod an over oiled K&N can put some oil inside the intake tube. Such an oil film will attract some dust particles that are visible, but they're so large they shouldn't have gotten past even the worst filter on the market, and air with this size of dust particles in it doesn't meet EPA clean air standards.

I assume you meant to say "dust visible INSIDE several intake tubes was amazing"? This makes me wonder why you went ahead and bought the truck? What did the compressor wheel look like? After 50K with a K&N cylindrical filter I discovered that my compressor wheel was thoroughly dusted when I had to replace the turbo due to the turbine having contacted the case!

The pic below is the wheel from the new turbo after driving only 500 miles with a freshly serviced K&N and a new K&N filter cover which I tried for the first time because I thought it might help improve filtration. You can already see some ding marks on the new wheel. When I saw that wheel I immediately dumped the K&N setup and installed a 7.3L AIS!



The pic below is the new WW wheel I installed to reduce surge, and those leading edges are sharp enough to cut a finger, I know!

 

I follow you now. When I first read it I thought you were saying due to the high speed airflow, dirt would not be deposited on the intake tube, even if you left the filter off.

Do you think this would be a problem? The grass laying around the filter box was what was trapped between the side of the filter and the box just barely hanging on and not getting sucked into the turbo wheel.

 

Chris- I don't see a problem with the pics you posted. The grass was there to help catch dirt, duh. Love the mud stains inside the intake tube also...

 

Actually, I never bothered to look at the wheel on that truck or many others. I guess I wasn't clear in my earlier post Gene. I looked at about 25 trucks before I found one I thought was acceptable and the wife liked. Of those 25, there were 2 I though were good and 1 possible, the rest I just told her no way. The one we ended up with had an AFE stage 2 on it from day one. You'll at least have to admit that is superior to the stock set up. UOA came back very favorable in it also.

 

The first pic of the intake wheel that shows the leading edges starting to round off from dirt.Is this from your cat engine or power stroke? In the under hood picture where does the red hose connect to? air compressor intake? If so check the hose out dirt can be entering there. I use hot water and soap to clean out the intake tubes when changing out turbo or updating intake wheel. This way i know its all nice and clean.

 

That first pic was taken about 5 years ago of the 99.5 wheel that came out of my new (rebuilt) early 99 replacement turbo. After 500 mi I removed that new 99.5 wheel because of surge and installed the early 99 wheel shown in the second pic.

My C7 only has 21K on it and it's got a Donaldson power core filter so hopefully its compressor wheel is still ding free!

That's a pic of Clux's truck and I think that red hose is the return from his homemade CCV filter. BTW, all that dirt you see in his engine bay is the reason he cites for not pre-filing his oil filter!