Can someone explain how an AOS works? How its installed? What its good for? I have heard that they are the same as a catch can and that they are different...? I have also heard that they are good for higher mileage cars...? True? False? Before you post a lmgtfy link, I would like it explained from someone who actually knows how they work and explained in layman's terms if possible. Any help is much appreciated as usual!
My understanding they act as a catch can but return the oil back into the engine so you don't lose oil. I know there's more but that's the jist of it.
hrmm...somebody correct me if I'm wrong, but this is my impression The purpose of a catch can is to 'catch' the oil vapors produced in the crank case. And AOS actually separates these and returns the 'oil' portion of it back to the crank. This requires removing the PCV valve so you can have drainage when you're not under vacuum (boost). Theoretically, you run both crank case vents to the AOS, along with the return line. You then run a line from the AOS to the intake (vacuum source). The vacuum source will pull the vapors out of the crankcase and into the AOS. When you're not under boost and there's not much pull from the intake side, what's collected in the AOS then drains back into the crankcase (that's the key difference between an AOS and catch can). You need this because you have two pressures in the cylinders, one from the combustion process, the other from the vapors within the crankcase. You want to remove these crankcase pressures to help reduce the force needed on the power stroke (did I say that right?). This is why (I think) higher mileage cars will benefit from one. The main issue you may recall from a couple months ago a lot of us big power guys were having was the intake vacuum was pulling WAY to hard, and it was actually pulling stuff through the AOS and into the intake (which then went through the FMIC, TB, intake, cylinders, exhaust, causing a lot of smoke and bullshit). Ming's turd AOS isn't a turd if you're running anything 20g or smaller, it just can't handle big power vacuum. No matter how you plum it, there's always issues. I actually removed the intake hose and vented it to atmosphere to keep my crank case pressures from building up.
Ask Rick and Kokopelli how much 'crap' was in the catch can that 'caught' all the mess out the output of Ming's AOS. Kokopelli called me asking why the catch can was almost full of crap......that was only a month's worth of junk.
The catch can was full of water when I pulled it off the car. I have never seen that before so I was concerned that the motor may have been shot. When I saw it I double checked the lines and everything was run correctly. Not sure why there was so much condensation in the system but I am sure I will not be running the AOS on any of my cars. I have been vta with the crank case and valve cover vents for over 5 years now and have never had any issue related to crankcase pressure. I run the lines to my ghetto campbell soup catch can and rarely have any crap at the bottom of it.
I think that AOS just sweats too much in the cold weather and that is where the water came from.....still I don't want that crap in the engine so I VTA.
Thanks for the responses guys! So, what is the general consensus? Is it worth it to run one for say a bugeye with 106,xxx miles on it? It has never been once been low on oil and I rarely get into much boost.
I'll be copying Mike's setup but with the institutional size tomato juice can or maybe one of the vintage Quaker State oil cans I have. Money for an AOS can be better spent on something else like a couple of tanks of gas or steak dinners.
Wirelessly posted (G1) I have one to sell too. Guess I am not much of a salesman. It wouldn't sell here anyways so its up on nasioc.
essentially, but Mike said it correctly...Ming's piece of shit is, well, a piece of shit. However, people all over the states seem to like it, so none of us should have a hard time selling it to anybody on Nasioc.
In your specific case, Bug-Rex, I think the money is better spent towards the replacement water pump and timing belt work at that mileage.
well its down to 75 bucks and still not selling...the word is obviously out! Bugrex - Bring Mike and I a case of Fuller ESB and its yours.
Don't cheat yourself on that, replace the pulleys as well. Ghost's was rather crunchy when he tore his motor down
LOTS of built up goop from the factory pcv system! On quite a few motors we have torn down for that matter.
How does goop from the PCV system make it to the 'front' of the engine? And under the timing cover where the pullies live nonetheless?