Real Fiero Tech

Mann & Hummel ProVent

https://www.mann-hummel.com/fileadmin/u ... n_2013.pdf

Literally industrial strength air/oil separator. I'll get one for The Mule in addition to installing the crank I'm prepping with corrected bearing clearances.

The Poi has been installing those on everything lately. They are very nice indeed.

Very nice, looks to be much better than a run of the mill catch tank.

The Dark Side of Will wrote:Mann & Hummel ProVent

https://www.mann-hummel.com/fileadmin/u ... n_2013.pdf

Literally industrial strength air/oil separator. I'll get one for The Mule in addition to installing the crank I'm prepping with corrected bearing clearances.

Ever thought of getting some of those air injection reaction (A.I.R. pump emissions) system exhaust check valves and installing those into your exhaust system and then hooking up your crankcase breather to them so you could use the exhaust scavenging effect as a positive crankcase vent system?

Sinister Fiero wrote:

The Dark Side of Will wrote:Mann & Hummel ProVent

https://www.mann-hummel.com/fileadmin/u ... n_2013.pdf

Literally industrial strength air/oil separator. I'll get one for The Mule in addition to installing the crank I'm prepping with corrected bearing clearances.

Ever thought of getting some of those air injection reaction (A.I.R. pump emissions) system exhaust check valves and installing those into your exhaust system and then hooking up your crankcase breather to them so you could use the exhaust scavenging effect as a positive crankcase vent system?

I'd like NOT to blow oil smoke out the exhaust...

My current theory is that the larger bearing clearances I have now are resulting in excess crankcase windage oil, beyond what the OE oil separator can handle.
The ultimate fix is to install a crank with the right bearing clearances, but additionally I'll use the ProVent to be sure.

Isn't there a windage tray from the factory? Also how much extra oil windage will you save by tightening the bearing clearances by a couple thou? Come on man I think its almost going too far. your theory might be right, but iwlsiy worth all that extra work?

All motors have blowby. Maybe its your rings gapped too much if you think you have too much crankcase pressure.

I am sure with a boosted setup my crankcase pressures are way higher than yours but I never saw it as an issue.

do you want to do all this work cause you want more power? I don't understand why you want to go to all the trouble.

For one thing, it blows oil smoke in embarrassing situations. I can't show off an engine I built myself and then have it blow a puff of oil smoke when I start it

It's making great power and once I clear out the system with 1-2 WOT pulls, it doesn't smoke on further pulls. I don't think it's blowby. I'm also running gapless rings, so it's not ring gap.

My current engine has .125 in2 of gap area in the bearings. This is equivalent to a .400 diameter hole.
That's with .0023 main clearance and .003 rod clearance
At the clearances it should have (.015, .018), those numbers would be .076 and .310.
That means I have 66% more oil coming out of the bottom end bearings than I should.

The stock PCV system, from the windage tray to the oil separator is designed for stock oil volume. Also, because the Northstar has so much less windage than an LS1 stock, the Northstar's PCV oil separator is tiny. The LS1 drains top end oil back through the V and over the rotating assembly, putting considerably more than just bottom end oil in the windage. The Northstar's top end oil drains directly to the pan through dedicated drain back passages.

My ultimate goal with this engine is 450+ to the wheels naturally aspirated, using as much RPM as I have to use to get there... so all the waterfowl have to be lined up before I'll be able to do that.

With those clearences maybe try a thicker weight oil to lower that 66% down. With the power you want to make and rev to, thicker oil might be necessary. I say try a thicker oil and see what happens. It could confirm your suspicians or maybe not but it would be less time consuming then ripping it all apart

I *KNOW* I want to fix the bearing clearances. That's happening regardless of any other factors. It's not that I am guessing that I should replace the crank in a flailing effort to reduce my oil consumption.

I want to understand the whole system so that I can make sure it doesn't have any unintended functions in the future.

The Dark Side of Will wrote:For one thing, it blows oil smoke in embarrassing situations. I can't show off an engine I built myself and then have it blow a puff of oil smoke when I start it

Do you think the ProVent will be able to handle the amount of oil vapors your engine will produce without itself producing an annoying oil vapor smell?

I have doubts the ProVent will be able to handle a very large quantity of oil vapors without some kind of annoying side-effect. Those vapors have to go somewhere. If you want to pull all of the vapors out of suspension, you'll need some kind of condensing unit and a reservoir tank to store the byproduct.

The problem isn't vapors so much as droplets. The mass of vaporized oil is tiny considering the low vapor pressure of oil.

And since droplets are what an oil separator is designed to separate... Yes, I think it will work.

The ProVent has 3 ports... air inlet, air outlet and oil drain. Connect the air inlet to the PCV valve on the valve cover, connect the air outlet to the PCV inlet on the manifold and connect the oil drain to the pan... possibly by Y-ing into the dipstick tube. The system ends up no more open than the PCV already is.

The Dark Side of Will wrote:The problem isn't vapors so much as droplets. The mass of vaporized oil is tiny considering the low vapor pressure of oil.

And since droplets are what an oil separator is designed to separate... Yes, I think it will work.

The ProVent has 3 ports... air inlet, air outlet and oil drain. Connect the air inlet to the PCV valve on the valve cover, connect the air outlet to the PCV inlet on the manifold and connect the oil drain to the pan... possibly by Y-ing into the dipstick tube. The system ends up no more open than the PCV already is.

Well it is going to come down to how much oil volume the ProVent is designed to handle and how much your Northstar is going to produce.

Sinister Fiero wrote:

The Dark Side of Will wrote:The problem isn't vapors so much as droplets. The mass of vaporized oil is tiny considering the low vapor pressure of oil.

And since droplets are what an oil separator is designed to separate... Yes, I think it will work.

The ProVent has 3 ports... air inlet, air outlet and oil drain. Connect the air inlet to the PCV valve on the valve cover, connect the air outlet to the PCV inlet on the manifold and connect the oil drain to the pan... possibly by Y-ing into the dipstick tube. The system ends up no more open than the PCV already is.

Well it is going to come down to how much oil volume the ProVent is designed to handle and how much your Northstar is going to produce.

Compared to the stock oil separator, any of the ProVents are huge, and are shaped for ideal performance, while the stock unit is shaped to fit where there's space available. I don't think it will be a problem... especially once I get the new crank installed to get the windage oil volume back to what it should be.

My '88 Fiero DOHC track car smokes upon startup after a track session or autox on a hot day. I think it's the same issue here, except in my case the oil is getting too hot and thins out instead of having large main clearances.

Series8217 wrote:The Poi has been installing those on everything lately. They are very nice indeed.

Where does he buy his?

The Dark Side of Will wrote:

Series8217 wrote:The Poi has been installing those on everything lately. They are very nice indeed.

Where does he buy his?

He doesn't remember except that it was from a Google search and it was some Diesel parts place.

Diesel Filters seems to have the best price ($129 shipped): http://www.diesel-filters.com/393107055 ... f-highway/

Everyone I've read goes straight for the ProVent 200. Is that because of its "power" rating? It's built for industrial diesels, and a 330 HP industrial diesel is a HUGE engine compared to most car engines. The ProVent is obviously sized for a flow rate. I guess that's double proxied through crank case volume and approximate *diesel* horsepower. My educated guess is that design PCV flow rate is proportional to crank case volume, and industrial turbo diesels in a given power range are all mostly going to have similar crank case volumes.

That being said, I'm not sure how diesels achieve PCV flow since they never make any manifold vacuum. External mechanical pump?

I'm sure there's no harm (other than where to put it) with going bigger than necessary, so I'll just snag a 200. Thanks for the tip on the supplier!

Ordered for $119, as well as a way overpriced check valve.

The Dark Side of Will wrote:Ordered for $119, as well as a way overpriced check valve.

I think I'm just going to manually drain mine unless the volume ends up being pretty significant.

All of my diesels just have a line from the valve cover straight to the intake manifold or in between the turbo and the airbox. The engine drawing air in will draw in the vapors despite it being at a very low vacuum.

To make EGR work on non turbo cars Mercedes put in little throttle body flaps that opened up off idle, that created some vacuum at idle to draw in EGR

The turbo cars have "mixing plates" in the charge pipe and the turbo effectively blows the EGR into the motor.