Head external oil return

[Randomguylite]

Hi everyone first time caller.

I was just wondering if anyone was running a external oil return from the head back to the sump. Any pics, what parts used and placement of the return back to the sump would be great.

Cheers

[boost_boy]

Hi everyone first time caller.

I was just wondering if anyone was running a external oil return from the head back to the sump. Any pics, what parts used and placement of the return back to the sump would be great.

Cheers

Not around here that we know of.......

Dee

[meminto]

Try the uk site..

sxoc.com

there are threads in that forum about the modification your after..

[Randomguylite]

Thanks I found what i was looking for.

http://www.sxoc.com/vbb/showth...t+oil

[themadscientist]

Good god, what a nightmare setup.

[float_6969]

I really don't think it's necessary. I think that most of the oil starvation problems associated with the big end bearings of the rods is due to improper PCV routing and flow restrictions. It's a known fact that the CA doesn't have a great PCV setup and suffers from poor elimination of crankcase gasses. If the gasses aren't properly released, it can cause seals to leak, dipsticks to blow out, and if it gets bad enough, the oil can't drain out of the head, causing the sump to run dry. Without thinking outside of the box, it makes sense to think that if the sump empties at sustained revs that the oil can't drain out of the head fast enough. But if you think one step further and ask WHY the oil can't drain fast enough, and take into consideration HOW the PCV setup works, it will make sense that an improperly setup, or poorly working PCV system can cause the oil starvation, and no amount of external drains will really fix the problem.

I'm aware of this all of this and have some very simple solutions that should help tremendously.

I believe that the CORE of the problems lies in how Nissan decided to get the crankcase gasses out of the crankcase and up to the head. The VERY large diameter (7/8" IIRC) tube at the top of the oil filter, the oil drains from the head, and the dipstick tube, are the ONLY paths the crankcase gasses have to evacuate. The original design is that the tube on the top of the oil filter routes the gasses up to the back of the intake side valve cover. From there the gasses are either eliminated via the PCV valve under manifol vacuum, or are passed from the intake side of the head to the exhaust side of the head an into the turbo inlet under boost. The problem lies in the tube that goes from the top of the oil filter mount and up to the head. The first thing that happens is that the 7/8" tube instantly reduces to about a 5/8" tube. Then the tube flattens out to clear the intake manifold and starter, immediately after it's flattened out, there is a sharp 90° bend, and the tube is further reduced to a 1/2" tube. Once they gasses make it to the head, they are SUPPOSED to be removed VIA SUCTION into the intake of the manifold or the turbo. This system will work if the rings AREN'T worn, and the tubes are routed like they're supposed to be. But what commonly happens is that ppl will not want those gasses routed into the the engine (for obvious reasons), so they'll route the tubes to a catch can and then to the atmosphere. The problem is that the suction, that is so VERY important for the system to work, has now been removed. Also, if there is any obstruction to the tube leading from the crank to the head, the system won't work either.

What I've done to my car is eliminate the tube under the intake. That tube is (or WILL be rather) routed to a catch can, and the outlet of the catch can is routed to an electric smog pump commonly available on many automobiles for emmistions. I removed and capped the tube in the intake side valve cover, and installed a breather on each valve cover. The PCV valve has been removed and the hole plugged, as well as the hole on the intake of the turbo. The pump is simply wired into the electrical system to run when the key is in the ON position.

This allows for multiple things to happen at once. -First is that the crankcase gasses are eliminated from the crankcase AT the crankcase, not though the head. - Second is that none of those gasses ever even have a chance of entering the motor. -Third is that fresh air via the valve cover breathers is CONSTANTLY being drawn into the motor. The ONLY path for the air to reach the crankcase is the oil drain tube. In theory, this will draw oil from the head down with it.

Although I'm still in the middle of building this system, I'm VERY confident it should eliminate any problems with oil starvation. My ONLY concern is with the air traveling down the oil drains. I fear that if the force of the air traveling down the tubes is greater than the force of the oil trying to drain back into the pan, it's possible this could cause oil pooling in the head again. I believe this would only be a problem at idle though. Once the revs and boost increase, the pump is going to be eliminating the gasses from the crankcase and not trying to draw air into the valve covers.

Sorry for the long and wordy post! If you read all of that, I hope it helps.

[r34 gtr]

Thoughts on the front mounted head breather box thingy off the CA18DE that dude uses on page 5?

I'm not really pleased with his execution, but the box itself seems really neat. I would be game to buy one if someone had one to sell me.

Or is it totally unnecessary?

Actually, I know its completely unnecessary for my needs, but its cool and I haven't seen it before and I waaannnt itttt.

[bentvalves]

i run one of those front mounted air/oil seperators to give the head main galley a breathing point.

[float_6969]

I don't really see how it's any better than the valve covers. If anything it's worse because there is no baffles to separate the oil out.

Also, don't forget that PCV stands for Positive Crankcase Ventilation. Crankcase being the key word. We're trying to remove gasses from the crankcase, not the head. the only reason there are gasses in the head at all are because of the tube running under the intake, and gasses coming UP the oil drains.

[meminto]

I agree with floats points, however I still believe that vacuum assists removal of crankcase gasses through the stock pcv system.. (It even describes that it SUCKS gasses out in the fsm)..

But all good, I plan to hook a manometer up to a good stock ca to get some baseline data and test various different setups to see the variances....

I will post some data when i actually get a chance to do it... lol

[ca18detgabby]

enjoyed reading that thread as well as what ryan had to say.

lots of interesting ideas.

PS yes tim I agree they are very neat

[r34 gtr]

The front mounted breather box thing IS baffled like the valve cover breathers. The guy states that it is many times.

Whether it helps or not, it does look cool. Looking cool = everything.

[Randomguylite]

I'm not going to the extremes as what the guy in the thread did. I'm looking into running the twin catch can setup with the external drain.

[bentvalves]

I don't really see how it's any better than the valve covers. If anything it's worse because there is no baffles to separate the oil out.

Also, don't forget that PCV stands for Positive Crankcase Ventilation. Crankcase being the key word. We're trying to remove gasses from the crankcase, not the head. the only reason there are gasses in the head at all are because of the tube running under the intake, and gasses coming UP the oil drains.

Its not better persay rather it allows the head to breathe from another point, the main galley, away from spinning camshafts. It is heavily baffled with steps as well to keep oil down. Its not really the gasses that I am worried about when I speak of the head breathing, but rather keeping oil down in the pan. I no longer run a PCV, all head breathers routed to a large catch tank. I noticed that when I gave the head more places to breathe, that I would push less oil into the catch tank when it was being caned. More places to freely exhale = less oil being puked into catch through 1 hose (high velocity) oem setup per exhaust side valve cover.

[r34 gtr]

So does anyone know where to get one of those boxes? Did they come in the FWD pulsar, and if so, does anyone have the part # so I can impulse buy one at the steal-ur-ship? Or does anyone have one they want to sell me?

[bentvalves]

yea either sxoc - post in wtb or go to nissan and have them pull up the images of the ca16de? engine and point it out to them, speaking with them over the phone is a waste of time.

[r34 gtr]

Sounds like a lot of hassle. Getting on a plane and going to England sounds like the easiest way to get one. Might have to try that - though I don't know US Customs' position on me importing car parts in carry-on luggage these days.

[bentvalves]

it shows d-stirls as the last poster in this thread via the CA forum, what gives?

[r34 gtr]

Dude this forum has been freaking out lately. I don't even know what to tell ya.

[bentvalves]

leads me to believe his post was edited/removed, its a conspiracy I tell ya....he knows something we dont.

[D_Stirls]

i deleted what i wrote but the name stayed there.

EDIT!!MR GTR; I'll do it again now, just to prove it to you since your questioning it;


Modified by D_Stirls at 1:36 PM 2/15/2010

[r34 gtr]

Interesting if true.

[bentvalves]

well what do you know that we dont know d-stirls.

and make me a CAS holder that utilizes both dowel pins dangit

either that or warranty one of your current models for me in that if I wear out a camshaft spline, I send you back the plate and you refund my money.

rudimentary really, nothing to it but to do it.