Sooo, here I am reading along and minding my own business, and I see a thread that mentions air filters. Air filters, hmmm, I have a question, that maybe hasn't been asked before. . . or maybe it has and nobody cares.

Now, before you get your knickers in a knot about what "brand", that's not what I'm going after. . . I don't have asbestos underwear on either, so flame throwers to stun their Scotty.

Anywho. . . when one installs these high flow super deluxe air filters, does this effect the operation of the CDR?

If I understand this properly, in order for the CDR to operate, there must be a pressure difference across the air filter to come up with a few inches of water column vacuum. Now, if you have a high flow air filter, seems like that amount of resistance is now null and void. Meaning, that your crankcase no longer has any "vacuum" on it. Now, there maybe some slight pressure in the crankcase, and that will "push" air through the CDR. However, isn't the crankcase supposed to have a little bit of vacuum to keep that Texas Tea in the crankcase?

Just thought I'd throw that out for a few ideas.

Never measured it, but I'm willin to bet the turbo puts a rite good draw on it when sucking hard, probably splains why I still get oil in the tube even tho I run a hi-flow filter.

I've always noticed oil going back up the boot to the airbox to some degree when cleaning it, possibly at idle, the vapors have less draw on them.

OEM spec'd pressure drop spread - 4~6" - is measured thru clean GM Approved AC filter, with high end across used filter still within service period - that tell you anything?

And, good thinking, kn - I think I can safely retire, now...........................;) :cool:

Naw you can't GMCTD
You'd be missed to much around here

Come on, JD, you can't hang up your spurs yet. . . . your pupils are still awaiting to learn more :)

Thanks, guys - so, one final lesson in answer to a previous post - "are all 6.5 blocks born with cracks?"

No, my friends - all 6.5's are not born female.........................

Hint: somebody hit a local junk-iron emporium, find a 443 Navstar V-8 engine block (7.3 PowerStroke).

Measure the length of the cylinder block along the head deck surface, front-to-rear.

Measure from the front wall of any cylinder to the front wall of the adjacent cylinder, for the center-to-center bore spacing.

Measure thru the main bores from the rear main web outside wall to the front main web outside wall.

Write all this stuff down, 'cause there will be a test, later.

Next, do the same with a 6.5 GM\DD engine block.

Then, inspect the crankshaft material for each marquee, noting which is cast iron, and which is forged steel.

Just for grins, take the dimension from rear flange to nose, or better yet, place them adjacently on the ground.
Note the dimension, anyway, just for posteriority's sake.

Post your dimensional data here, to aid in the ensuing speculation, name-calling, and engineer-bashing which is sure to occur, and will be a must-attend event.