On relieving crankcase pressure, PCVs, catch cans, breathers and whatnot...
#22
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The reason I mentioned the PVC is related to Six's method of opening both of the ports and combining to a single catch can, as noted above. I suppose you could add a separate cold side port and keep the PVC.
Six will typically make note that he does not like the idea of introducing any oil or oil vapors into the intake manifold due to detonation due to octane reduction. I have no idea how the fits into your Meth / water injection.
And, I also realize that you have run the PVC for some time now, presumably without negative effects from oil build-up.
If you did run the PVC, then the VTA catch can would have to supply any make-up air needed during PVC flow.... assuming that is a real thing (more flow being asked for by the intake manifold / PVC valve than is supplied by the blow-by). I don't see that as a problem with most catch can designs I am aware of, but just mentioning.
Six will typically make note that he does not like the idea of introducing any oil or oil vapors into the intake manifold due to detonation due to octane reduction. I have no idea how the fits into your Meth / water injection.
And, I also realize that you have run the PVC for some time now, presumably without negative effects from oil build-up.
If you did run the PVC, then the VTA catch can would have to supply any make-up air needed during PVC flow.... assuming that is a real thing (more flow being asked for by the intake manifold / PVC valve than is supplied by the blow-by). I don't see that as a problem with most catch can designs I am aware of, but just mentioning.
#23
I'm also doing breather experiment with my TimeAttack NB. Before those 3x 16mm hoses I got oil blowby through oilpan seals. Now its much better, though my oilstick is still popping up.
Next step is going to measure oilpan pressure through oilstick tube. If there's any possitive pressure I just add T piece in my AN10 turbo oil return line and connect it to the valve cover breather hoses
#24
One idea I have had for a bit and not had the time to play with would be to have a second vacuum source from the exhaust system for when the engine is in boost a lot or for long periods of time. Basically Tee off from the main PCV vacuum source and run it to the downpipe after the O2 sensor, put in a couple check valves to keep exhaust gases from being pulled into the intake. I think this method would have vacuum from the exhaust side while under boost and still maintain vacuum from the intake when off throttle and idle conditions. Still keep the catch can of course.
https://www.summitracing.com/parts/m...oaAq0bEALw_wcB
#25
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Shouldn't that be rotated 180 (facing the other direction) for proper venturi effect?
You need low pressure at the orifice opening; this setup loads it with high pressure...
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My thoughts on your question is that it honestly doesn't matter where you evacuate the crankcase pressure from and dont think going through all that work to pull from the oil pan would gain any improvement over the valve cover, but you could be onto something and if anything it would be a cool experiment.
My thinking is, if the oil can freely drain back to the pan, I will not be blowing it out of the valve cover vent.
But then again, I could be dead wrong. Hence the discussion.
#28
The only advantage I was trying to achieve by pulling crankcase gases from the oil pan was theoretically eliminating the flow of the said gases up to the valve cover through the drain holes in the head, where the up-rushing gases make it difficult for the oil to go down in the pan and just pool in the head.
My thinking is, if the oil can freely drain back to the pan, I will not be blowing it out of the valve cover vent.
But then again, I could be dead wrong. Hence the discussion.
My thinking is, if the oil can freely drain back to the pan, I will not be blowing it out of the valve cover vent.
But then again, I could be dead wrong. Hence the discussion.
#29
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Regardless of where it comes out, atomized oil is going to come out. Separating it from the vapor and capturing it should be the goal.
Intuitively, I do like the idea of a large-diameter hose running up from the pan to a large catch tank filled with a complex material. When I feel that way about something, it usually means that it will either work beautifully or fail spectacularly.
#31
yea hole in the side of the block by the front oil sqirter location works well for venting blow by. I'm a few tweeks from this setup now but it has been working good for years now. If I remember what I did right the path into the valve cover baffles near the back of the head is blocked off drilled holes between chambers so both connect to the center path. the back of the head just collects too much liquid oil when you are driving the snot out of a car that will accelerate at an extreme level.
https://www.miataturbo.net/attachmen...-p101d0005.jpg
https://www.miataturbo.net/general-m...m-thread-55877
https://www.miataturbo.net/attachmen...-p101d0005.jpg
https://www.miataturbo.net/general-m...m-thread-55877
Last edited by bbundy; 05-07-2019 at 12:52 AM.
#35
@aidandj tried something like that with negative results. I don’t remember the details.
I think it it was wise to have called Sixshooter.
EDIT: Having re-reread: Actually, I think Aidan drilled through he block side.
I think it it was wise to have called Sixshooter.
EDIT: Having re-reread: Actually, I think Aidan drilled through he block side.
#37
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After talking to Sixshooter on the phone and discussing the issue at length, I am convinced his method will be the best approach.
And, Joe has a point, too. Even if I successfully vent the oil pan, I still need an elaborate system to separate the dirty laundry.
So, I came up with an idea for a location for my breather tank...
See the windshield washer bottle with a black pump on it, right next to the intake manifold?
I will just relocate that. Inside the front bumper, ahead of the right front tire, under the headlight. There is plenty room there. I may buy a larger washer bottle, we'll see.
All I need to do is add a filler neck and extend the said neck into the engine bay, at a point just behind the headlight.
And then, I'll fabricate a nice breather tank and baffle it correctly to rid the gases of any liquids being carried. Two inlets going towards the bottom with 90* elbows, a layer of steel wool layered on a mesh 3/4 of the way up, and a breather filter on top. That is the basic idea. The top will be removable to replace the steel wool if I need to.
I have 15 x 10 x 20 (wxdxh) available to me there, which gives me a 3 liter volume. I do not have to make the tank that big.
I will incorporate a sight glass to check it at a glance - that's easy to do, and it will have a drain+petcock plus a capped tube extending all the way down to draw the oil using vacuum. (I can just use engine vacuum at idle to suck the contents in a sealed container, or push a tub under the car and open the petcock..)
I will not weld the outlet ports, they will be threaded in, locked in place with slim nuts on the other side. There will be 5/8 ID hard lines running to the back of the head for a clean look, and the rest will be just 5/8 ID hose.
Current hotside port will be threaded and capped with an acorn nut.
I really do not want any welding on the valve cover - preparing the thing for sandblasting and powdercoating, and then getting all the abrasive grit out of it is a royal pain in the ***.
Oh, hard lines and the breather tank (plus all the intake piping for the turbos) will be powdercoated black.
Cool. I love a plan.
Time to get to work.
And, Joe has a point, too. Even if I successfully vent the oil pan, I still need an elaborate system to separate the dirty laundry.
So, I came up with an idea for a location for my breather tank...
See the windshield washer bottle with a black pump on it, right next to the intake manifold?
I will just relocate that. Inside the front bumper, ahead of the right front tire, under the headlight. There is plenty room there. I may buy a larger washer bottle, we'll see.
All I need to do is add a filler neck and extend the said neck into the engine bay, at a point just behind the headlight.
And then, I'll fabricate a nice breather tank and baffle it correctly to rid the gases of any liquids being carried. Two inlets going towards the bottom with 90* elbows, a layer of steel wool layered on a mesh 3/4 of the way up, and a breather filter on top. That is the basic idea. The top will be removable to replace the steel wool if I need to.
I have 15 x 10 x 20 (wxdxh) available to me there, which gives me a 3 liter volume. I do not have to make the tank that big.
I will incorporate a sight glass to check it at a glance - that's easy to do, and it will have a drain+petcock plus a capped tube extending all the way down to draw the oil using vacuum. (I can just use engine vacuum at idle to suck the contents in a sealed container, or push a tub under the car and open the petcock..)
I will not weld the outlet ports, they will be threaded in, locked in place with slim nuts on the other side. There will be 5/8 ID hard lines running to the back of the head for a clean look, and the rest will be just 5/8 ID hose.
Current hotside port will be threaded and capped with an acorn nut.
I really do not want any welding on the valve cover - preparing the thing for sandblasting and powdercoating, and then getting all the abrasive grit out of it is a royal pain in the ***.
Oh, hard lines and the breather tank (plus all the intake piping for the turbos) will be powdercoated black.
Cool. I love a plan.
Time to get to work.
#40
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The project will have to wait a few days. I had to fly to the Capital to translate a training course for race horse farriers.. That will take a couple days, and then there is a movie script to translate, too.
I just hate it when work gets in the way of play time...
I just hate it when work gets in the way of play time...