alphax https://ozvolvo.org/discussion/comment/178026#Comment_178026
FYI - A camshaft can and will impact crankcase pressure, in terms of evacuation of the pressure. A stock PCV system uses relatively small diameter hoses and fittings - but they are aided in a big way by strong engine vacuum. When a camshaft is fitted that significantly reduces that vacuum, the little factory system may not keep up, leading to oil leaks. Add forged pistons with more piston to bore clearance and this will in-turn lead to more blow by and the problem is further compounded.
@ALVO360 I wouldn't give up on your big cam dreams, unless you want to daily the car. I'm sure you could find a way to increase the factory engine breathing by adding adding some breathers to the rocker cover or elsewhere, no? Pretty common thing to do on modified engines with already marginal breather designs. Usually weld a couple of fittings onto the rocker cover and run some large breather pipes into a catch can, then vent the catch can to intake duct.
Because the 360's B230ft conversion requires the use of the 360's sump, which has it's own dipstick port, I have decided to take advantage of the dipstick port in the block and use it as an additional breather. I've ordered some 12mm hose and a check valve, and just need to figure out how I'm going to run it to my Catch can.
I have also just setup my home-made oil fill cap breather.
Where it says flame trap, It should really say PCV/oil seperater.
I still have concerns that the setup I have will still be limited/restricted (as you suggested) by the small port size on the turbo intake pipe and catch can and I may benefit from installing a second port on my intake pipe and/or running a catch can with multiple ports for venting, or even a second catch can if I can't keep the pressure down.
Another reason I wanted to test a factory cam was compression.
My T3 cam reduced cranking compression down to 100psi!
The IPD cam raised cranking compression to 140psi.
I still feel this is a bit low and it was evident that the intake valve closing later in the compression stroke was the cause of this. The T3 cam wasn't closing the intake valves until half-way through the compression stroke. The ipd turbo Cam doesn't close the intake valve until 1/4 of the way through the compression stroke, which I still feel is several degrees later than it should.
If I can't get the crankcase pressure down with the above setup running the IPD turbo Cam, the A cam is going in and I'll be very interested to see if it increases the compression as-well-as reduces crankcase pressure.
The reduction in performance may be a compromise I'm willing to live with.
