Ok, I think im having issues with my PCV / Catchcan routing.

Here is my setup: Starting on the drivers side, line comes from there goes around to the top of the catch can. Bottom port of catch can goes out, under intake/tb, then around to the port on the drivers side. Yellow line goes from passenger side to throttle body.



Thoughts??

 

no pcv control between the crankcase and the intake manifold

 

Nice \fuel distribution setup you got right there!

Run an inline PCV valve just before the intake.

 

Thank you

So install a PCV on the line coming from the lower fitting of the catch can that wraps around and to the intake? Is this the right port to go into or should I go to the one on the passenger side? Or does it matter?

Can you explain why I need to put a PCV valve here?

 

That's correct and it doesn't matter because both sides pull vacuum. Now if your driver side valve cover had an orifice like what you see on the stock Gen 4 driver side valve cover then you would not need a PCV valve in the line. Are you getting excessive oil into the intake manifold?


This is a stock LS6 intake from my 01 LS1. The driver side valve cover did not have an orifice as mentioned and you'll notice there's a PCV valve at the end of the line that connects to the 3/8 hose going into the intake. I believe the Mighty Mouse can has a built in PCV valve and these are needed as they have a check ball or valve that opens and closes depending on engine operation.

I personally don't want the effects of PCV entering my engine as you cannot stop all the smoke/vapors from entering the engine but you can slow some of it down. The only way that I know to stop it all together is to not utilize the intake manifold in order to pull air on the crankcase but to just ventilate to atmosphere or even better run a vacuum pump off the crank to pull air through the crankcase and then ventilate to atmosphere.

 

Thanks for the reply. Here is my issue im having which is why I posted really. Im having issues with the engine starting and popping right off. I know I have fuel PSI. It just seems to blubber a little bit then take off. Also having issues with it coming down on idiel as I slow down as it downshifts. It seems to run rich like its way overfueling. Which is why I question my setup as im wondering if im pulling way to much vacuum?

 

The PCV valve regulates how much vacuum can pull through the crankcase. It's hooked into the intake and when the vacuum is high such as at idle, the PCV valve stops most of that vacuum. As vacuum drops with an increase in RPM, the PCV valve opens to allow a higher volume of gasses and pressure to be pulled into the intake. Have you installed a PCV valve in the line to see if it helped? This may be more of a fueling/tuning issue than a PCV related issue but you can try the PCV valve or even cap it all off and vent to atmosphere to see what it does.

Install one of these in the line just before the intake manifold and see if helped.

https://www.summitracing.com/parts/A...0783?rrec=true

 

Thanks. I will try it. I dont think its a tuning issue as the tuner is a well known and very experienced tuner. Im thinking this is making it hard for him to tune it. Hes not doing it in person, its via log file and email.

These are aftermarket two piece valve covers and the bottom piece that bolts to the head has a threaded hole in the middle of the cover where a (1/4 or 3/8 NPT to barb threads into. Then the line goes out the side of the cover as you see above and around to the catch can for the drivers and throttle body from passenger.

Here is a diagram the company I got the valve covers say to use but I really dont understand it and they say I dont even need a catch can ??? Can you make heads or tales of this?

 

Putting a PCV valve in the line just before going into the intake manifold will increase your manifold vacuum on deacceleration and idle. You don't need a catch can but it's already there and certainly not going to hurt. It will keep more of the blow-by and moisture from making its way into the intake manifold which is a good thing. It's the cleanest way over the alternative to deal with the fumes and vapors but not so much cleaner for the intake, cylinder heads of the engine and the catalyst.

 

OK great. Thanks for the replies. I will see how this goes and install a PCV valve

Did that diagram I posted from the company I got my covers from make sense at all?

Also does it matter if its before the catch can or after? Hopefully after because that line isnt solid hard line and I can put the PCV there inline

 

After having the intake off you can see a nice puddle of oil on the bottom of the throttle body. Does everyone have this issue? Is this mostly from the crankcase ventilation port located from both of the rear valve cover ports to intake manifold port or the small line from the passenger side valve cover to the throttle body? It would seem if it was directly in the tb blade opening it would be from the smaller line to tb as the intake port would take the oil down into the runners.

 

Another engine that's fallen victim to the results of positive crankcase ventilation. Installing a sealed catch can between the rear ports of valve covers and intake will slow it down some.

 

Oil consumption is a normal side effect of an operational PCV system. If this bothers you then you are in the market for a catch can. They are not all created equal, my suggestion is to follow the trail of happy customers.

 

I recommend the Mighty Mouse setup. It was just easier for me personally to buy everything from Mighty Mouse than to try and piece something together.

No more increased crank case pressure and blowing out the rear main seal
-Doesn't smell horrible once you pull it into the garage causing you to have to leave the garage door open for hours
-Built in PCV within the can itself = nice
-You can keep ls1 valley cover rather than having to swap it for an ls6

 

The exhaust from my tail pipes will do more to stink up a garage than a breather can will.

 

This is true but for some reason I was more sensitive to the smell of my first DIY catch can attempt than my exhaust lol.

 

 

I have somewhat of a unique setup which I may have to post pictures to help.explain. But I have an LS1 in a midengine configuration. The engine still faces forward it's just slid to the rear. The belts are up against the firewall behind the driver seat. Only the intake manifold is reversed so the throttle body points to the rear of the car...common for midengine setup. I have an LS6 valley cover with the PCV....IT's still pointing toward the front of the car, as it can't be reversed with the intake. I switched valve covers so they still orient with the throttle body, but the clean side cover is now on the dirty side. I built two catch can's that I was going to mount on the fire wall, and may change this for best routing/location.

First question. Regarding dirty/clean sides on the valve covers. What actually makes the driver side "dirty" and the passenger side "clean". Is it the valve cover vent location being in the rear of the engine for dirty? or something particular to that head that is different. I'm guessing my clean valve cover is now on the dirty side.

With the LS6 valley with two catch can's, I've read different things. Plug dirty side vent, join to clean side, join to valley etc. I thought vacuum in crankcase was improved by keeping the valve covers separated in terms of catch can's. or basically that it worked more effectively. I don't care about easiest, I care about best so should the dirty side valve cover (whichever side that is) be combined with the valleycover vent on one catch can OR should the dirty side valve cover be plugged and only run the valley to the can?

is the baffling on the valve covers specific to their locations on the side of the engine/head? In other words should I move them back because the clean side cover is going to be getting splashed with oil and i'ts not baffled appropriately there? This just means all the lines from the front of the engine (valley cover & clean side) will run around the engine to the throttle body.

Is there benefit to opening up the size of any particular opening/tubing? If all other hoses/barb fittings remain the same, is it better to run a bigger clean air line off the oil cap?

 

One valve cover orifice is small to meter the air so the manifold vacuum does not gulp too much air. As long as you orient the components as they would be in a stock arrangement, only reversed, you should be OK. Do NOT open up the metered orifice. It will mess things up. Consult a diagram for the stock PCV system if you feel you got it all confused.

 

Got it...as it would have been. That said, I never saw the PCV on this engine. The passenger cover doesn't have a rear fitting to join with the driver side cover...so I assumed it tee'd with the valley before attaching to the intake. I don't recall the driver side valve covers having a metered/small orifice, maybe that's because I didn't remove the baffle and it isn't visible. I'll try to take a look... I haven't wanted to take off the valve covers because I've been cutting and grinding on the car.

So with LS6/pcv valley...the dirty side valve cover should join with valley cover on one catch can? Does that depend at all on the dirty side valve cover orifice size? Again just not sure what leads people to say CAP that side.

Does large clean side AN line help?