Originally Posted by RAM EM
The biggest reason for a catch can isn't for reasons of prolonging engine life anyway, it's to keep oil vapors from mixing with the incoming fuel and lowering the octane, which promotes the detonation that Hemis are prone to, especially tuned ones. I've experienced this firsthand, and adding the catch can (which was recommended by my cmr tuner) helped alleviate this condition.
Obviously, a CC that has a way to seperate/filter the oil from the air going into the intake is going to be superior to one that doesn't. It doesn't have to be expensive or fancy, either. I have seen DIY cans that are true accumulator/seperators that cost about $50 to make, and I'm sure work quite well.
Our local CMR is a Hemi tuning specialist, and on top building custom Hot Rods up to 2000 crank HP
Does a ton of work on the new 5.7, 6.1 and 6.4L Eagle Hemi's
...but wont even take on a new customer until they run a Catch Can for at least a few weeks
to reduce the amount of oil film coating the inside of the intake manifold.
If you ever saw a Hemi with the intake removed, you would be shocked!
...and the amount of oil my BT Catch Can has removed from going back into the intake over the past 2.5 years is quite disturbing.