Order placed for my FIV. I guess so....it has been in my signature for a month. Lets discuss friggin CA emmsiions.. CARB. Have you looked into approval or meeting the requirements? I don't think it takes much for a CAI. But I THINK the engine breather line is required to be connected to the intake. Just in case the top of the engine "burps" any gases they are sent back into the engine to be burned? It does seem odd to me, that in an OEM aur intake uint, there is required to be a negative pressure on the top engine,which is what this line creates. This connection has been carried over to a lot of aftermarket unts. If a regular engine breather filter unit is used, in place of the tube to the intake pipe, then there is no longer a negative pressure in the top of the enigine. And why is this only required on 1 side of the engine. Most of the old style enignes had engine breather filters on both sides of the engine. I have seen 426 elephant motors that had 2 breathers in each valve cover. .. Maybe we should take some of this discussion to a different location? ..
Actually after a little quick inspection. I need ot rephrase the above statement. The part in red needs to be romoved. That was DUMB statement ......as many times as I have looked at my engine and the fact that I just had a COMPLETE new top end installed. SO I should, know the design in my dreams. I will write it off as a "senior moment". I guess it could be the effect of lack of "symmetry" with the oil breather and oil fill sitting on some "casting boss" on right side of the intake. The runner design leads you to think the complete manifold should be the same on both sides. The oil fill and the breather are actually piped into the oil valley area of the block (not into the top of the head as some engines do). Yes the breather shares the same area as the oil fill. But it appears not to be piped into the oil fill, it just enters the oil valley near the same location on a "casting boss".. (Wonder why it is done like that?). ..
Cause it can catch spill/overfill maybe. By the way, under normal operation I don't think that's "negative" pressure. Except in the case of a "burp", that's the intake for the positive crankcase ventilation. Volume sucked through the PVC valve creates a greater vacuum than the negative pressure in the intake tube.
The negatve pressure I was refering to was from the intake tube, especially under heavy acceleration. I am qute sure there is a negative pressure in the intake tube between the intake filter and throttle body (unless you are running boost....not naturally aspirated). Therefore this negative pressure is actually sucking on the breather line. Right?? Odd.... I don't think this line can used for boosted applications. You would not really want to push 10 psi into your oil valley. ..
Wrong (i think). Yes there is negative pressure in the CAI tube. But... the breather tube is connected to the crankcase, the crankcase is connected to the PCV valve, the PCV valve is connected to the intake. The PCV valve is a one way valve -- and it's connected by a 1/2" ID hose. The crankcase is ventilated. It's positive ventilation meaning that air is getting actively moved through there. It has to come in somewhere. That would be the breather tube in question.
It appears the breather tube is conneted to the oil valley, not the crankcase. So it is venting the top of the engine. If it were in the same location as the PCV, there would not be a need for the PCV to be pressure controlled. The crankcase would always be at atmospheric pressure due to the Breather filter. The PCV is connected to the crankcase. The PCV lets out any presssure buildup that is bypassed thru the pumping action of the pistons and any pressure that slips by the rings into the crankcase during compression or combustion strokes. .
