macnewma

I recently posted a question about Breather's and Catch Cans. After reading through the post and looking at a system that is designed to relieve crankcase pressure and maintain vacuum, I am confused as to how our engines deal with this.

Do we have a PCV valve? If so, is it associated with the Air/Oil separator located near the oil filler tube? If not, where is it and what does it connect to?

This Krank Vent system for turbo and high compression cars uses 2 vents. One goes from PCV to Intake Manifold. As per their instructions:

The other goes from the valve cover as is quoted from their instructions:

Krank Vents does not have experience with our specific engine. I am not sure that we would need both if we don't have both venting systems. I also want to make sure I will be installing my catch can correctly. From what I can tell, I will be installing it in series with the stock air/oil separator, correct?

I could not find it in the repair manuals that I have either. Maybe I am looking it the wrong place.

Thanks,
Max

David Floyd

We do not have a PCV valve

macnewma

So just to confirm, we only have the one line that runs from the air/oil separator to the intake just before the turbo that relieves crankcase pressure?

So in the case of the Krank Vents, only one would be needed?

Thanks,
Max

David Floyd

Correct, keep us informed on the Krankvent

biggles

Since we are on this topic. I have been trying to remove my oil/air separator in order to change the washers and install some new hoses, but cannot find a way to remove the bottom bolt. I would appreciate some feedback.
Thanks!

NZ951

Do all run catch cans like the lindsey unit not feeding back in, or like the Greddy / Cusco etc that plumb back into the intake? I am thinking Greddy in the front guard fedding back into the system...

NZ951

Though do these need to be emptied at any stage? Would be a pain to take all the plastic surround off each time.

TonyG

NZ951


Yes.... you would have to keep emptying it, and thus the reason that I tapped the bottom of the Greddy and ran it back to the oil pan.

The oil level sender flange can be removed and tapped providing an easy method of draining back into the oil pan (although you loose the oil level sender..... but if a person relys on this to check or verify the oil level, they shouldn't be driving a Porsche in the first place :-)

TonyG

macnewma

That is a small quirk with the Greddy. It doesn't facilitate removing the oil and water from the crankcase vapor.

Tony G, you have tapped it, but I am not sure I would want that oil to go straight back into the oil pan. The crankcase vapor contains more than just the motor oil. It would be a mixture of water condensation and oil.

If the water is in a very low concentration, than maybe it would be fine. I would prefer to simply remove the excess and topoff. My catch can will only hold 1 pint and my engine should be able to lose up to one pint.

Your thoughts Tony? I know that you know considerably more than I know about these beasts.

Max

NZ951

If anyone could devise a system that fits in the fender, as my clutch wont allow the Linsdey unit, that would be great.

David Floyd

Could you not mount the Lindsey unit in the fender ? Run the drain pipe out for easy access and would never have to be seen at all.

I may try to move my Lindsey unit out of the engine bay.

NZ951

Great idea, but I have already sent it back and dont want to pay for that unit again... I am sure it can be done much cheaper than them. Especially consider I wont need their mounting system. Also the hose length will all be different. I might just make one myself...

TonyG

macnewma

Your comments are exactly correct, and are valid considerations.

However, the factory system good or bad, returns the oil to the engine, and with that occuring, the engines can easily last 200,000 miles.

So while your points are valid, returning blow by oil to the engine sump will not affect the longevity of the engine by much in the big picture...as long as the oil is changed frequently (which is what is supposed to happen anyway).

Also, I think you'll be very surprised at how much oil will get collected if you are pushing the engine.


The main idea for me was to reduce substantially, the amount of oil that is burned via the factory oil breather system, which reduces oil consumption. The introduction of oil into the intake charge via the factory breather is why the intercooler/turbo/intake tract is coated with oil. It also has a substantial affect on the effective octane of the air/fuel mix entering the combustion chamber.


If you do not return the oil to the engine sump, you need to have an easy access drain valve with a line on it so that you can drain it easily and quickly without making a mess (not easy).

Lastly, you might want to consider filling your catch can with steel wool partially escpecially near the air exit side. This will catch the oil particles, but let the air through. The oil particles will fall, the air will recirculate. Nice trick. Goes a long way towards seperating the air from the oil.

TonyG

NZ951

If the oil gets put back into the engine, then all that is needed is a way to vent the pressure right? Then a filter and valve type system on the oil filler tube would suffice wouldnt it?

macnewma

Tony G-

How quickly does your catch can fill up when you are on the track? Actually, I guess you wouldn't know since you pipe it back in.

Also, the steel wool thing sounds interesting, but I would be concerned with small pieces of steel being sucked back into the intake or drawn back into the crank. How do you stop this?

Also, Tony, I don't know if you commented on the Krank Vents? How important do you think maintaining vacuum in the crank is? And how important is it to relieve the crankcase pressure? Do you think these devices are bogus?

Thanks,
Max