need help with catch can

dntgtbit

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ok guys. I am new here, I have a supercharged 95 cobra. I was told I need to run a catch can. I know what they do but I don't know what style I need to run. I also don't know how to run it. I know some people run a hose from the pcv to the catch can and from the catch can to the valve cover. I don't have a spot to hook it on mine. so I am lost. any help will be greatly appreciated. pics will help as well. thank you
 

TanTop94

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Can we have some pictures of your set up? If I see it I might be able to help you alittle bit more.
 

toyman

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You would only need a catch can if you have excessive blow-by. Using a catch can is not a fix for bad rings. Besides someone telling you that you need one what have you done to verify a blow-by condition? I would check the compression and do a leak down test to get an idea as to the condition of the engine. I'm running 9 psi and I don't have blow-by.
 
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dntgtbit

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I don't have any pics right now. I can give you a run down of the car.
Stock 95 cobra bottom end
Holley systemax upper-lower
Sct big air 3000 mass air
60 lb injectors
255 in tank fuel pump
255 inline t rex fuel pump
Bbk fuel pressure reg
Procharger d1sc intercooled
Mac long tube headers
Bassani x pipe
Bassani mufflers-catback
Im sure there is more thats off the top of my head while im at work.
As of right now I dont have the pcv in the car is almost back together and im not sure how to run the pcv with the holley intake. It doesnt have a spot on the intake like the original cobra intake had. Thats where the catch can came into play.

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TanTop94

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I just set up a quick set up on a foxbody with a Holley systemax intake, no blower though. So I ran it like this, PCV in lower intake, hose to catch can, then outgoing hose from catch can splices into a 3way hook up where it splices into where your oil neck on your valve cover is. Keep the original hook up for that though just have it done through the three way. There's a hole I believe if you have capped it on your upper intake, cap that if you haven't already.
 

Addermk2

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Your problem is likely the way your pcv system is routed. When running any kind if positive forced induction, the pcv system needs to be modified. Post up a bunch of pictures if your engine bay, and I'll draw you some diagrams.
 
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dntgtbit

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Please excuse the horrible pic's. My garage doesn't have very good lighting. Not sure what all you need pics of But I can get whatever you need. I apriciate all your alls help.

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dntgtbit

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Bump. Still trying to figure out what to do. If I dint run a catch can just run the pcv. Where do I run it to?

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TanTop94

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I believe the way I said would still work fine on your car...but I understand I know Addermk2 has some good info up his sleeve.
 

toyman

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I'm confused about changing the routing for a forced induction setup. The PCV is a check valve that closes if the upper intake is under pressure as in boost. Mine is hooked up as it came from the factory.
 
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dntgtbit

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My problem is the intake I run doesn't have the same hook up as my factory upper. I was asking where to route the Pcv to. The factory cobra intake ran from the Pcv to under the upper intake. The Holley intake doesn't have spot under the upper.
 

TanTop94

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My dads 89 has the same Holley intake. The shop we had do some work on it routed the PCV to the spot you have capped on the front of the intake by the TB. But this caused a lot of vacuum in the crank case and in turn we had a lot of blow by. The way I said above is a slight variation of what my Uncle, who is my most trusted mechanic told me to do. Haven't had a drop of oil in the intake since and the car runs better than ever.
 

toyman

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My dads 89 has the same Holley intake. The shop we had do some work on it routed the PCV to the spot you have capped on the front of the intake by the TB. But this caused a lot of vacuum in the crank case and in turn we had a lot of blow by. The way I said above is a slight variation of what my Uncle, who is my most trusted mechanic told me to do. Haven't had a drop of oil in the intake since and the car runs better than ever.

Something is mixed up. Blow-by pressurizes the crank case (combustion gasses leaking past the piston rings) not by intake vacuum. Ideally the crankcase should be under vacuum all the time. The air flow is from the air intake tube to the valve cover (fill neck) into the engine and up through the PCV back into the intake. This ensures that the metered air is returned to the intake and engine vapors are burned off to lessen emissions. I'm sure there is a place for a fitting on the intake for a line from the PCV. It may not be on the underside and it may be plugged off.
 

kb1982

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After buying my car, it sprung several oil leaks. So I thought about it, then pulled the pcv, and was able to blow through it. Went to the parts store, and tried out several and they had the same result. Ive heard the turbo coupe valves seal up good but I dont have any personal experience with them. So instead of taking a chance on sending pressure back into my crankcase, I installed a one way brake booster check valve from a 2013 impala. My setup consist of pcv, catch can, one way check valve, then to the manifold. On the oil filler, I run a breather filter. Im using a MSPnP ecm, which is speed density so unmetered air isnt an issue for me.
 

TanTop94

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I had oil blow by literally puddling in the CAI, I popped some of the PCV lines off and they would piss oil...this is a freshly built 347 with less than Im guessing 1500 miles. The way the PCV line was set up before was just a single hose lead from the lower intake to the upper intake, I have the same holley system as the op.

Now with constant amounts of oil coming from the PCV system that got spliced by a line for the charcoal canister I came to the conclusion that this is the problem as like I said there was oil all through these lines. First I deleted the Charcoal canister, then added in a catch can...

So my PCV system at the point was...a line from the PCV to the catch can, then a line from the catch can to the upper intake. Now this set up was better, though you could now see the amount of oil/ oil mist traveling through the lines into the catch can. While the CC did stop some of it, I was still getting alot of oil coming through and ending up at a low point in my CAI. At this point I had to sit back and try to figure out how there had to be an excessive amount of vacuum/pressure on the crank case that this amount of oil would be making its way back up.

I found that there was not a sufficient way of getting metered air into PCV/ crank case. That oil was most likely being pushed through the PCV system if there was any sort of high compression build up "compression braking/ excessive intake pressure". So this brings me to my current set up I have above....not only allowing metered air through valve cover, but also intake pressure as it is still behind the TB plate.

So I ran it like this, PCV in lower intake, hose to catch can, then outgoing hose from catch can splices into a 3way hook up where it splices into where your oil neck on your valve cover is. Keep the original hook up for that though just have it done through the three way. There's a hole I believe if you have capped it on your upper intake, cap that if you haven't already.

Not trying to be smart or anything, but as of now it has worked for me and I still has great oil pressure "50+ psi on a high pressure oil pump". Honestly if there is a problem with it I wish to know cause, ofcourse I wouldnt want to be starving the damn motor of oil. Just putting in my .02.

Here is a good read too, not in my defense, honestly just for the threads sake.
http://www.sn95forums.com/showthrea...rtation-and-the-Alternatives-(Updated-4-02-07
 

kb1982

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Gotta love blowing out the dipstick. Always made one hell of a vacuum leak for me, and created idle issue and stumbles when letting out of the throttle. My first failed attempt was to install an anchor tight lokar dipstick for 96 dollars. Bad move, oil leaks soon followed. My next experiment was unplug the pcv hose all together, and plug the port on the manifold. After reninstalling the non locking dipstick with the pcv unhooked, no more pushing out of the dipstick. This is what led me to believe the pcv wasnt sealing enough to keep boost from reverting back into the crankcase. I installed the brake booster check valve with the pcv hooked up, and had rising disptick issue solved. The oil issue was still present, so next was the catch can. After all this, Im still fixing oil weeps that all this caused, but it seems to be working for me. I think both valve covers vented to or using a breather (or two) would be about the best you could hope for venting the crankcase in no vacuum situations (high load) short of using a dedicated crankcase evac pump (expensive). I thought of trying the smog pump converted to an evac system, but read that the oil that makes it past the catch can will make them fail pretty quickly. When I switched out headers, I bought the ones with the egr port, so I could try the old school full drag car method of using the exhaust flow to pull pressure from lines hooked to each valve cover if my woes continued. This method would prolly wreak havoc on an O2 sensor in that header if any oil got into the system, but I was running a single wideband on the driverside anyways. Sorry for the long rant. I think this is an issue that there are several ways to skin the cat, each person just needs to find out what will work for them.
 

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