Which way would you run it?
I can see pros and cons to both. When you left of the gas exhaust gas reversion will cause the vacuum at the exhaust scavenger to drop off, but the suction from the motor should keep up the vacuum, the downside to this is that shitty oily air will run through the motor… This is only on decel, though, so I think it would be very minimal…
Or I can just set it up like this supra (but w/ a catch can)
Interested in hearing thoughts and opinions…
dont most people just use a smog pump now for this? ie a little electric pump to force the air into the exhaust check valve?
could run two catch cans. But then its getting way complicated.
I think Id just run it like the supra, but with the catch can. You thinking one line with a T like you show it, or two lines all the way back to the exhaust like the supra?
Id think youd want to use -12 for these. I think thats what the nipples on the check valves are sized for if I recall to back when I had a kit like this.
Dan
Ok, I figured out the second sentence: “let off the gas”
why even run it into the exhaust, a properly setup catch can will get rid of nearly 100% of the blow by, with enough filters on the can and properly sized lines i dont think you will have a problem with crank case pressure
the exaust flow PULLS the air out of the crank case… ie its more effective becasuse its not a passive system
newman, i belive there are checkvalves to help with the DECEL dropoff
eh?
maybe its just a difference in motors, tony1 (http://www.t1racedevelopment.com/) couldnt get any better results than just venting through the valve cover ( like this http://www.t1raceparts.com/product_p/catch%20can%20kit.htm and block ( he tried just about everything and has the results to prove it, even expensive dry sump setups)
This makes NO sense. The exhaust scavenging would fight the intake vacuum and one or the other would never work.
I would just go with diagram 2.
the exhaust scavenging would set the check valve on the intake side and vice versa, no? Having it on the other side of the catch can does nothing since the catch can is just open in the middle, but this way any sludge pulled through gets left in the catch can not in the intake… pressure is equal in all directions…
diagram 2 fo sho
Or you can just get a catch can.
diagram 2.
make sure the evac valves dont leak before you put them on. ive seen them leak.
the best bang for the buck is off of a 80-90’s ford pickup. they run these valves for a smog pump and they work great and you can snag them at a junkyard.
ive seen as much as 30" of vac in a tight motor with restricted inlet to the valve cover. thats a bit high but if the valves are installed correctly, they work well.
this valve ^^^^^ was the one that pulled down 30".
I was thinking, even on decel the motor is still moving, which would still draw a vacuum right?
ugh, I hate not knowing things. lol
But the evac can create negative crankcase pressure. It can amount to decent power gains, even…
just my .02 i have found with lots of testing where the placement of the tube is inserted will change results. i have found that if a car even has a muffler and even high flow it must be mounted after or there is no suction at all and if no check valves are used you will get pressure instead with a muffler you get to much pressure built up for it to even work so pretty much get more hose good luck
+1 devioustsi and myself were just talking about this today while looking at my motor.
2 catch cans is better then one and still effective.
2 is always better than one.
