PCV Oil Separator

[jeffgrice]

Gang,

I was reading a few articles about guys putting an oil separator on the PCV line to protect the motor/intake, etc from too much oil entering the intake process.

I have a roush 427sr with 11k miles.

Not being the "wrench" seeking advice if this is a valuable modification to make.

Thanks

Jeff

[patrickt]

I put in an ME Wagner adjustable PCV and a Moroso oil separator. It requires a little bit of custom fabbing, but nothing major. It makes a significant difference if you have a large carburetor-based FE, as it will help you eliminate the "hot idle" problem that has been written about a zillion times. I love mine. Putting it in could be a fun project.

[RockBit]

Like Patrick, I also added an ME Wagner PCV valve and Moroso oil separator to my FE. The separator catches a noticeable amount of oil even though my valve covers are baffled underneath the PCV.

I would think you want the oil separator rather than having the oil go through your engine.

[PaulProe]

I also, am running the ME Wagner PCV valve and put a oil separator in the vacuum line. I was really surprised on the amount of oil that was caught in the bowl. Probably 2-3 oz per 1000 miles.

Paul

[kevins2]

Guys, which Moroso oil separator model are you using?

Thanks,

Kevin

[patrickt]

Originally Posted by kevins2

Guys, which Moroso oil separator model are you using?

Thanks,

Kevin

You're going to have to fab it up a little regardless of which one you choose. Mostly you want the two ports on the separator to be angled in the directions that you want (PCV valve and carburetor power brake vacuum port for me). Then you want the included fittings angled properly. Other than where the holes are on the separator, and what the included fittings look like, I think all the Moroso "smaller" separators are really the same. As I recall, I think the one that looked like it would work the best for me was the smaller canister for a Miata. But what you have to do is just flip through all the separators on-line until you find one that you can say "OK, I can fab that one in without jumping through too many hoops." It really is a nice little upgrade.

[kevins2]

Thanks Patrick, I assumed I'd need to fabricate my own bracket and you just confirmed what I thought I was seeing in that a lot of the differences were simply the mounting bracket. Both of you have ports on opposite sides (180 degrees) and one straight fitting and one 90 degree fitting, which would also work for me. It appears that most of them come with 90 degree fittings. I see the Miata versions have one of each... Interesting way to decide on a specific part!

Kevin

[RockBit]

I think the different prices shown for the small Moroso separator are because of different mounting systems that are made to fit specific cars. Since I knew I would not be able to use the included mounting bracket, I just ordered the cheapest one. I think it came with straight fittings, so I got a 90 degree fitting for the side that goes to the carb.

I made the bracket out of 1/8 aluminum and designed it so I can unscrew the bottom of the separator and empty it without removing anything else. The bracket is bolted to the rear bolt on the intake manifold.

[patrickt]

Originally Posted by kevins2

Thanks Patrick, I assumed I'd need to fabricate my own bracket and you just confirmed what I thought I was seeing in that a lot of the differences were simply the mounting bracket. Both of you have ports on opposite sides (180 degrees) and one straight fitting and one 90 degree fitting, which would also work for me. It appears that most of them come with 90 degree fittings. I see the Miata versions have one of each... Interesting way to decide on a specific part!

Kevin

It's like going to PepBoys and asking the guy at the counter if you can just go in the back and rummage through the hoses until you find one you think you can trim to fit between your water pump and radiator.

[kevins2]

Thanks Chris, the rear intake manifold bolt is exactly what I was looking at on my car. I have a couple of ground wires attached there but that's no problem.

Appreciate the info everyone.

Kevin

[PaulProe]

I made my own separator from a Big Box Store air compressor oil/water separator. They typically are 1/4NPT in and out so you'll need some hose adapter fittings and a bracket. Works well and much less than the Moroso ones.

Paul

[kevins2]

Got the Wagner PCV valve and Moroso air-oil separator in:



Couple of things I encountered with my particular set-up. First, as I was tuning the PCV valve, I couldn't get the vacuum to drop to zero as expected. One of the possible causes of this is too much restriction on the air flow into the engine. I had a pretty standard issue chrome breather on the other valve cover and, when I removed it, the vacuum dropped to zero as desired, so I ordered one of these:

Spectre Performance ExtraFlow Breather


The second thing I had to deal with is that my pentroof valve covers are not baffled and Wagner indicated that would likely be a problem. They indicated a customer solved this with baffled grommets (another customer said they didn't work, so it remains to be seen). Anyway, I picked up a set of Spectre Performance 5333 baffled grommets and with these and the new breather, the PCV valve tuned as expected. So, if I have high oil consumption, I can make and install baffles in my valve covers - a couple of chrome cap nuts won't look bad.

Paul indicates he's collecting 2 - 3 oz. per 1,000 miles. What are the rest of you experiencing? It'd be nice to have a benchmark to see what I encounter.

Kevin

[patrickt]

Originally Posted by kevins2

Paul indicates he's collecting 2 - 3 oz. per 1,000 miles. What are the rest of you experiencing? It'd be nice to have a benchmark to see what I encounter.

I think that's pretty accurate. My VC is baffled around the valve, and sucking oil was never a huge problem to begin with, but it was a slight problem. What really brought it to my attention was the fact that I had a plain old rubber hose between the carb and PCV valve and the oil would literally leach through the rubber over the winter, when the car was not driven for a good five months. It was the darnedest thing to put the car away for the winter and then open the hood a few months later and find the PCV hose covered in oil droplets. Of course, just upgrading the hose to a fluoroelastomer fuel hose stopped that leaching and adding the Moroso separator was just an added touch to catch that little bit of oil before it went in to the carb base.

[twobjshelbys]

These "catch cans" are one of the biggest auto scams ever invented. You understand that the amounts being spoken of amount to "drops per 100 miles", are insignificant in any sense of the word and well within the capacity of the intake system to deal with it. If you are collecting MORE than that then you have a significant problem that needs to be addressed!!! Seriously, if it were a real problem don't you think the auto manufacturers would include them in the car?

[Kit Coyle]

I agree with Twobjshelbys...these are simple cars...why go out of your way to make
them more complicated. KISS.

[patrickt]

What's funny is that I pour my old leftover two-cycle gas/oil mix in to my Jeep but I put a separator on the Cobra's engine to catch three or four ounces. But tweaking these cars unnecessarily is half the fun of owning them.

[Kit Coyle]

Well, Patrick, I can't disagree with that. Tinkering really is half the fun! These cars
are a tool users heaven!

[kevins2]

Originally Posted by twobjshelbys

These "catch cans" are one of the biggest auto scams ever invented. You understand that the amounts being spoken of amount to "drops per 100 miles", are insignificant in any sense of the word and well within the capacity of the intake system to deal with it. If you are collecting MORE than that then you have a significant problem that needs to be addressed!!! Seriously, if it were a real problem don't you think the auto manufacturers would include them in the car?

Yes, the catch can is unnecessary. So is the Wagner adjustable PCV valve, no arguement. In fact, the entire car is unnecessary which is one of the things I love about it.

On a more serious note, since I decided to install the Wagner PCV valve and have unbaffled valve covers, I'll actually get some utility out of the catch can. I will be able to see if I've created a problem since this PCV valve is known to suck up oil without baffles. My first approach was to try baffled grommets but that's probably too easy. If I'm not happy with the amount of oil collected, I'll make baffles. Wagner did an oil consumption test with two different baffle designs and pretty much took the guesswork out of it.

http://mewagner.com/?p=1221

So, one unnecessary project may very well lead to another

Kevin

[RockBit]

Originally Posted by kevins2

Paul indicates he's collecting 2 - 3 oz. per 1,000 miles. What are the rest of you experiencing? It'd be nice to have a benchmark to see what I encounter.

Kevin

I haven't measured super carefully, but it looks like I am getting about 2 oz. per 1000 miles. Very similar to Paul's number.

For those of you that don't think the oil catch can is worthwhile, you are missing out on the fun of designing and making a bracket to mount it. They say problem solving staves off Alzheimers, so it is a good preventative mental health exercise.

I may even deduct it from my income taxes this year.

[RET_COP]

I wouldn't copy anything that came out in the 70s on American cars. If it keeps oil no matter what amount out of the intake it's a plus. I don't like the fact that it's an internal air leak and a faulty junk pcv will mess up the tune.