Yes, but this method won't suck it back into the intake.
I think if your catch can is working well, it pretty much removes the concern about filthy crap going back into your intake.
But as I said, time will tell.
Revised catch can setup - thoughts oh wise ones?
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Re: Revised catch can setup - thoughts oh wise ones?
I've been thinking about how I want to run my crank vent system once I supercharge it, and I want to ask a question with your setup hybrid.
If I was to delete that line completely that goes from the intake manifold to the catch can, would it still work?
In my thinking(which is most likely wrong), under idle/no boost, there will be vacuum in the manifold, which means it will be drawing fumes in via the intake system. Under boost, the supercharger will create a vacuum, drawing fumes in again via that same line.
Is there really a need for the intake manifold to catchcan line?
If I was to delete that line completely that goes from the intake manifold to the catch can, would it still work?
In my thinking(which is most likely wrong), under idle/no boost, there will be vacuum in the manifold, which means it will be drawing fumes in via the intake system. Under boost, the supercharger will create a vacuum, drawing fumes in again via that same line.
Is there really a need for the intake manifold to catchcan line?
Re: Revised catch can setup - thoughts oh wise ones?
Do you NEED it? No.
But:
1) There would not be enough vacuum created in front of the supercharger at idle to pull any fumes out unless you had a really restrictive filter (which you obviously dont want).
2) There is a bypass valve (AKA blow off in the turbo world) between the supercharger and manifold which is wide open at idle and light throttle (pulled open by vacuum). Any fumes pulled in via that front line would be blown back into the atmosphere while that valve is open. It could get a bit stinky and smokey potentially.
3) If you only use one of the lines, you can only pull the fumes during vacuum OR boost, not both.
My setup provides draw from the crankcase theoretically all the time. The one way (check) valves I put in each line makes sure air can only go in one direction, and only air from the crankcase will be pulled.
When I didn't have any crankcase vacuum - just breathers on each rocker cover going to the catch can, I actually had slight oil leaks around the sump.
Once I put this system in, no sign of it again. It seems to be a common theme.
Edit: one other thing I forgot about. I didn't want to suck too much crap through the supercharger, so the PCV should do the vast majority of the work.
But:
1) There would not be enough vacuum created in front of the supercharger at idle to pull any fumes out unless you had a really restrictive filter (which you obviously dont want).
2) There is a bypass valve (AKA blow off in the turbo world) between the supercharger and manifold which is wide open at idle and light throttle (pulled open by vacuum). Any fumes pulled in via that front line would be blown back into the atmosphere while that valve is open. It could get a bit stinky and smokey potentially.
3) If you only use one of the lines, you can only pull the fumes during vacuum OR boost, not both.
My setup provides draw from the crankcase theoretically all the time. The one way (check) valves I put in each line makes sure air can only go in one direction, and only air from the crankcase will be pulled.
When I didn't have any crankcase vacuum - just breathers on each rocker cover going to the catch can, I actually had slight oil leaks around the sump.
Once I put this system in, no sign of it again. It seems to be a common theme.
Edit: one other thing I forgot about. I didn't want to suck too much crap through the supercharger, so the PCV should do the vast majority of the work.
Last edited by hybrid on Sun Jun 25, 2017 10:24 am, edited 1 time in total.
Re: Revised catch can setup - thoughts oh wise ones?
http://grannys.tripod.com/evac.html
I'm no expert on this subject but how would something like this work on your supercharged engines ??
I saw this link on anther forum a while back.
I'm no expert on this subject but how would something like this work on your supercharged engines ??
I saw this link on anther forum a while back.
Re: Revised catch can setup - thoughts oh wise ones?
Yep that would work.
Notice in his update though, he's switched to using PCV for normal driving, and now switches the electric pump on during wide open throttle.
I'm not a fan of replacing mechanical stuff with electric generally, but it's definitely another option.
It doesn't return the fumes to the engine for burning either.
Notice in his update though, he's switched to using PCV for normal driving, and now switches the electric pump on during wide open throttle.
I'm not a fan of replacing mechanical stuff with electric generally, but it's definitely another option.
It doesn't return the fumes to the engine for burning either.
Re: Revised catch can setup - thoughts oh wise ones?
Yeah sweet, I forgot about the bypass valve. As i'm running a maf, mine will be recirculating, so I don't exactly want potentially oily fumes being recirculated in the intake tract.
Re: Revised catch can setup - thoughts oh wise ones?
Yeah you could go in after the MAF, depending on where it's located. For sure wouldn't want those fumes going through a MAF.
Re: Revised catch can setup - thoughts oh wise ones?
See it would have to go in before the maf because it would not be metered. So with the bypass it could potentially do a couple rounds through the maf, no good.
Re: Revised catch can setup - thoughts oh wise ones?
Hey Hybrid, I still haven't let this go ha ha
For a mafless setup, do you think this would work with the normal run of the mill 2 port catch cans, which is what I have. The blue arrows are check valves. I think it's similar to your setup but using only two ports instead of three.
Under manifold vacuum, the check valve in the line to the intake will shut. Once you're on boost, the manifold check valve will shut due to boost, and all the fumes will now go via the intake.
For a mafless setup, do you think this would work with the normal run of the mill 2 port catch cans, which is what I have. The blue arrows are check valves. I think it's similar to your setup but using only two ports instead of three.
Under manifold vacuum, the check valve in the line to the intake will shut. Once you're on boost, the manifold check valve will shut due to boost, and all the fumes will now go via the intake.
Last edited by Husky65 on Thu Aug 03, 2017 2:26 am, edited 1 time in total.
Re: Revised catch can setup - thoughts oh wise ones?
Yeah that should work in a similar way to mine, as long as there is enough vacuum from the supercharger intake to pull open the PCV.
If you have a very good flowing filter, your vacuum in front of the supercharger may not be all that high, but give it a shot.
At the very least, you will still be pulling fumes out of the crankcase under general driving conditions.
Edit: By the way, I can modify your catch can easily enough if you want to add an extra port. Or, if you could get hold of an inline PCV, you could run a non-pcv valve cover breather and move the PCV into the line going to your manifold. That way, manifold vacuum will still open the PCV, but the supercharger can pull fumes much easier when you're on boost.
If you have a very good flowing filter, your vacuum in front of the supercharger may not be all that high, but give it a shot.
At the very least, you will still be pulling fumes out of the crankcase under general driving conditions.
Edit: By the way, I can modify your catch can easily enough if you want to add an extra port. Or, if you could get hold of an inline PCV, you could run a non-pcv valve cover breather and move the PCV into the line going to your manifold. That way, manifold vacuum will still open the PCV, but the supercharger can pull fumes much easier when you're on boost.
Last edited by hybrid on Thu Aug 03, 2017 2:57 am, edited 1 time in total.