[Paul Dykstra]

I just added a crankcase ventilation system to my 4AGTE tonight. It uses 2 PCV valves so that when the manifold is under vacuum it works like stock but under pressure it vents to the compressor inlet.

What have most people done for crankcase ventilation?

I added this because A) it was easy and B)I'm having an intermittent oil smoke issue that I hope this might help.

 

[donalson]

i'll do what the HKS manual says... PCV on the valve cover to right before the turbo inlet...

simple

mark

 

[BRANDO0o0O]

I was planning on putting a small breather filter from autozone on mine.. is there a reason I shouldnt do that? I'll be MAP sensored..

Brando

 

[Jakub]

Mine runs to a catch can which used to go before the compressor, but now will have a small filter on it since I'm running map.

Only reason I wouldn't put a filter directly on the valve cover is that it could get your engine bay dirty over time.

 

[BRANDO0o0O]

Ok, I didnt think there was any problems with having just a small breather filter on there as long as ur MAP..

Brando

 

[1985_mr2]

i have a question: if the pcv hose goes from the valve cover to the intake, and all the fumes from the crankcase get sucked out wont that cause a vacuum inside the crank case and maybe suck the gaskets for the oil pan or valve covers in?

 

[Jakub]

No, not nearly enough vacuum. The problem with turbo setups is that you pressurize your crankcase, which is really bad. That's why you always want to move that hose from the intake manifold to before the compressor.

 

[Paul Dykstra]

The factory arrangement puts vacuum on the crankcase everytime there is vacuum in the intake.

That's exactly why I used 2 check pcv valves. That way when there is intake vacuum the vapor will be sucked in and burned. But under boost the vapors can run back to the compressor inlet.

Turbo's don't like to drain back to the pan if there is any crankcase pressure. I was hoping this migh be my oil smoke problem, which is why I tried it.

I suspect now that the problem is simply my oil drainback arrangement to the pan doesn't have enough capacity. I drilled out the factory oil cooler return to M12 and used 2 M12 banjo's and a long banjo bolt. This arrangement seemed to work with my old turbo location, which was top mounted. The old setup had a long return hose. I think the long hose allowed it to drain back slowly. The new setup is in the more standard location near the oil filter. This makes the hose pretty short, only about 8". I think I'll just drop the pan and poke another hole.

Thanks for all the thoughts.

 

[Paul Dykstra]

I think I have figured out my smoke problem. It should have occured to me and now I feel like a dumb ass.

My turbo oil drain flange is below the oil cooler outlet. That means since they share the same return the oil from the cooler can back up and fill the turbo drain line.

I am 99% sure this is my problem.

Again thanks for your time!

 

[feral4mr2]

i made a pvc catch can for my 4agte, i will plumb it before the turbo oneday as createing a good vacum in the top end of the engine can help free up more power. some v8 drag racers use a belt driven vacum pumps for this purpose.

i'll have to upload the pics again, as they dont work in the thread i did about it.

 

[feral4mr2]

oh, so you didnt have a seperate drain to in the sump for the turbo?

i have a 5/8 return for the turbo alone.

 

[Paul Dykstra]

Exactly I was sharing the drain for the oil cooler and turbo.

I got away with it with the top mount :smile: turbo

 

[feral4mr2]

i thought the oil cooler drain would be to small for the turbo drain. the cooler lines are only 3/8, what size fitting is at the banjo fitting?

i got a 5/8 bit of pipe brazed into my sump a little further to the front of the engine and slightly higher than where the banjo fitting is.

 

[Paul Dykstra]

Using the factory cooler drain location for both. I drilled out the factory threads and re-threaded the fitting to M12 but it seems too small for both the oil cooler and turbo. I should have known better.

I made female NPT bungs yesterday to weld to the pan this weekend. I will have one 1/2" return for the cooler and a 3/4" return for the turbo. This should fix my problem.

 

[elballoonrat]

paul, do you have any pics of your top mount setup? and why did you switch?

 

[Paul Dykstra]

I have some pictures somewhere. When I find them I will post a link.

I didn't have any major problem with the top mount setup but it did put a LOT of heat into the engine compartment. I had to shield everything. Before I got everything properly heat shielded it actually would vapor lock the clutch!

I wanted the advantage of pulse charging and I had the thing all apart anyway to replace a piston and headgasket.