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Oil catch can/ PCV help needed

R

Runningriot

Member
Could use some help/expertise in this area.

Background info. With my old valve covers, I'd get oil blown out the driver's side breather cap at high RPM. Both were open breathers.

With my new valve covers, no more oil out the breather caps. Now it blows oil out the dip stick tube at high RPM.
Engine is very strong, and isn't smoking at all. So I really don't think its an engine issue. I don't think I've ever had the breathers set up correctly.

Here is my engine currently.
23j020i.jpg


Would a set up like this help or just make the issue worse?
10rmm40.jpg

Now my understanding is that those are open breathers that run to a catch can. No PCV valve.
Or should I just run a PCV valve on the one valve cover and run the line to the carb?

Now there is also a possibility that I'm running too much oil.... My Moroso front sump oil pan is 7qrt. Should I be filling it with 7 qrts? Feel like thats a stupid question but would be a really simple solution.

Any help or insight on how to set up breathers would be greatly appreciated.
 
Last edited by a moderator:
Re: Oil catch can/ PVC help needed

I think this will solve your problem. It should maintain vacuum under wot and lower rpms by having one hose attached before the TB blades (or carb) and one after the TB blades (and that's where the can needs to go). I'd suggest getting one (PCV valve) for a 302. On the oil level, it should be filled to the mark on the dipstick, provided it's the correct dipstick for that engine. I "assume" this is a new engine, and if so, the blow by may lessen as the rings seat. To me, a PCV is a must to keep the acids down within the engine. On very high performance engines with very low or almost no vacuum, a hose ran from each valve cover to a venturi which are welded in the lower part of the exhaust system. This is mostly done on race cars.
 
Re: Oil catch can/ PVC help needed

On my old 289 race motor, I tried the catch can with a hose coming from each breather and I still got a little oil under the hood. Once I routed each breather hose down to the header collector (via one way valve), the engine comp has stayed clean. I still have it setup this way with the street motor in the car.
 
Re: Oil catch can/ PVC help needed

BTW it is PCV not pvc. Pvc is a plastic and PCV is got " possitive crankcase ventilation"

Mel

Sent from my DROID X2 using Tapatalk 2
 
Re: Oil catch can/ PVC help needed

"guruatbol" said:
BTW it is PCV not pvc. Pvc is a plastic and PCV is got " possitive crankcase ventilation"

Mel

Sent from my DROID X2 using Tapatalk 2
Click to expand...

Doh, missed that :roll
 
@ 67 evil eleanor: I guess what I'm getting at is a 7 qrt pan actually 7 qrts at initial fill up? I do agree, I think I need to install a PCV. Just not entirely sure what the best way would be for me to run it. Do I plum it to the carb, or intake, or headers? Or can I run a PCV with a catch can instead? I like the idea of keeping any sort of blow by out of my intake.

@ silverblueBP: Do you have any pictures of your set up? When you say "one way valve", is that the same as PCV valve?

Thanks!
 
OK now that we have the PVC vs PCV out of the way.

I was on a forum for my Hemi and have noticed a catch can seems to be a very common upgrade on the newer Hemi engines. the reason is that the engineers at Dodge in an attempt to limit emissions have run the crankcase ventilation in to the intake and the oil tends to gum up the internals thus causing reduced MPG over time as well as parts failure eventually.

Now the history of the PCV is in the late 60s the federal government required auto makers to meet certain standards much like today so we saw many changes, padded dash boards among other things. Prior to these standards, the auto makers used a draft tube. It took the blow by out and condensed it and let it run out a tube on to the roads as you drove.

Soon the PCV was created in order to allow the blow by to enter the intake system and be burned.

IMHO the PCV should be routed into a catch can and then the can could be emptied. However never empty the oil back into the engine.

Mel
 
@ silverblueBP
Thanks for the link and pictures!

Quick update for those interested. I drilled and tapped my intake in the valley behind the carb and installed a brass hose barb. Ran the rubber hose to the back of the carb and spliced this
http://www.summitracing.com/parts/smp-v112/overview/
into it.

Seems to have solved the problem I've been hammering it at WOT and no more blow back through the dip stick tube.
 
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