Originally Posted by Hampton CIT
So I'm outside looking at my engine doing what many of us do, thinking what next? I've been wanting to pick up a JLT Oil Separator for a while. It occurred to me that on an old Datsun 240Z I used to have, had its crankcase breather being a small filter shaped like the one on a CAI but maybe two inches tall. Going this route begs three questions I'm thinking.
1) Will the filter get saturated with oil so quickly that it will defeat its purpose?
2) Plugging off the space where the PCV attaches to the intake: will that mess with the car's computer as the MAF sensor won't be calibrated for the reduction of air, although slight?
3) My mind is thinking crankcase internal air pressure. I don't know if this matters or not just something that makes one eye squint in thought.
If this was something worth doing, I'd think there would be a bunch of aftermarket companies making these crankcase filters for v6 mustangs which they are not. This is certainly not something new. My old Datsun with the breather was a 71'. For our cars; bad idea or someone always has to be first?
1. It depends on your driving habits, auto vs standard / how much you engine brake, and how much power you're making to determine how much blow by you have.
2. Not sure what you mean by "reduction of air." Air enters the crankcase from the drivers side valve cover from the intake - this is Post MAF - and goes through the crankcase, out the passenger side valve cover and into the intake manifold. If you put just a breather on the drivers side PCV, or the oil fill cap, and leave the passenger side connected to the IM, you will be pulling in unmetered air and create a vacuum leak. The system either needs a breather on both sides, or to be left in the stock configuration.
3. Yes, venting the crankcase will reduce CC pressure. It will also mean that your engine seals, piston rings, etc are no longer subject to vacuum, so there's something to consider there as well. There are differing schools of thought, so you can make your own decision on that, as there have got to be 100x catch can threads covering that by now.