Crankcase breather catch cans

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coloradohill

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I am looking to get away from the usual pcv valve system for the street.

My in progress build is a Indy headed 416 with a tunnel ram and two Holley 660 center squirters.

The carbs don’t have vacuum ports so I have been running one inch spacers with ports for the pcv with my current Edelbrock heads.

The valve covers for the Indy heads are setup for header ventilation.

Looks like a dual inlet catch can is a good solution. From what I’m reading, a baffled can is the way to go with a filter for the outlet air.

I’m looking for recommendations on this , cans to go with, advice on plumbing the system ect.

Looks to me like you just run lines from the valve covers to the can. Is this correct?

TIA

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Mainly because the fabricated valve covers are setup for header evac and I don't want to fab breather / pcv grommet outlets. I'm trying to use these covers and thought it would be easier to go with a catch can.

I guess I could convert these to a pcv system if I think it over more. I'm open to suggestions.
 
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I would use the header evacuation setup with a catch can on each side, in between.
 
Oh yeah, I would also fab up a simple/baffle shield piece in front of that valve cover vent there, if it doesn't have one already. Your call.
 
I'm not running it yet. But it seems to make sense to have a vacuum on the can's exhaust for positive ventilation. What's your thoughts?
I'll be running mufflers and would like to use a separator to keep the oil out of them.

Thanks.
 
coloradohill said:
I'm not running it yet. But it seems to make sense to have a vacuum on the can's exhaust for positive ventilation. What's your thoughts?
I'll be running mufflers and would like to use a separator to keep the oil out of them.

Thanks.
Click to expand...
I would use a PVC system. Evac system and mufflers don’t go together
 
Can you pull the tank filter and verify that both of the ports are free to go into the can? Some setups have a dip tube off one of the ports to be used as either open or closed system types…if you happen to get enough oil in there and the dip tube gets covered you’ll only be using the open port. Draining often enough can mitigate the “concern” (it’s not much of one, just worth noting).

Otherwise, just one tube 10AN or larger from each valve cover will make that a nice open system. Putting it lower promotes oil draining down to it rather than pooling in a belly, or draining back to the engine which you don’t want either since a decent portion of the mix is also fuel vapor…helps keep the oil a touch cleaner.

Also, what brand valve covers are those? And did they come with the bungs in them? I like em!
 
Not sure if this would work with a header Evac system but I just bought one of these universal Moroso air/oil separators. Moroso 85497 It's not cheap but it's a quality part for sure.

I haven't installed it yet so I can't say how it works at the moment but the concept makes sense. It's filtered and comes apart to drain the oil and clean the filter. Mine is a street/strip car so I'm going to use a PCV valve but I don't think it's a requirement to use one with the separator.
 
I haven’t bought a can yet, trying to get thoughts on which is the better manufacturer. They seem to be all over the place as far as price. 20.00 Amazon to 400.00 +/- race cans.
Makes sense that the baffled ones are more efficient.

I’ve been looking at the vacuum pump / separators also. Pricey and not sure if it would be better to stay with pcv valve.

I like the idea of keeping the combustion as clean as possible.

I forgot the make of the covers but they are a fairly well known brand.
The builder has them and I’ll get him to check.
Thanks again
 
coloradohill said:
I haven’t bought a can yet, trying to get thoughts on which is the better manufacturer. They seem to be all over the place as far as price. 20.00 Amazon to 400.00 +/- race cans.
Makes sense that the baffled ones are more efficient.

I’ve been looking at the vacuum pump / separators also. Pricey and not sure if it would be better to stay with pcv valve.

I like the idea of keeping the combustion as clean as possible.

I forgot the make of the covers but they are a fairly well known brand.
The builder has them and I’ll get him to check.
Thanks again
Click to expand...

I would do a Wagner adjustable PCV valve, put a catch can between it and the manifold and then run your evacs as well.

This isn’t new. Jenkins was doing it before 1975. At idle the PCV does most of the work. At a cruise (even up a return road and such) the PCV is working its hardest and the evacs are now working. At WOT the pan evacs do all the work.

Thats how I’ve done it for a long time. Like I said, Jenkins was doing it back in the day. I didn’t figure it out myself. I ain’t that smart.
 
coloradohill said:
When you say unless the mufflers are that bad.
Do you mean oil soaked?
Click to expand...

No. I mean they are so restrictive they don’t let the pan evac function. There should be check valves on the stand pipe in the collector. That should keep any backpressure getting to the crank case.

IIRC, there were some of those baffles that had steel reeds in them and some had fiber reeds. They both wear out and need to be checked because they will both eventually fail. The fiber reeds fail much quicker because they can’t take the heat.

In fact, I forgot who told me about the reeds but I remember he said the fiber reeds sealed better than the steel ones but wore out much quicker.

I know guys who’ve run the same baffles for years and years and never checked them. The best I did was two seasons on alcohol.
 
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