I hope I posted this one in the right category, otherwise please move this thread.
As the title says, I have a problem with oil consumption.
I come from Germany and we are a few people which have that problem but we cant find any answer.
So I want to try my luck here and hope you guys have more experience with it than we do.
But at first my engine configuration:
-Saab B207 engine blok (open deck with cylinder wall supports)
-Z22SE (L61 2.2l) crankshaft
-GM Z20LET rods
-GM C20LET Mahle Pistons
-Ported LSJ head and LSJ intake manifold
-ZZP Stage 2 LSJ cams
-Harrop 1320 with 75mm pulley
-LS4 thorttle body (74mm)
Boost is between 1.0 and 1.1 bar and it makes 420HP and 430Nm.
Engine has seen ~1.000km.
We all have got slightly different engine setups, but we all have got ~400HP and the engines are nearly new.
The problems are the same.
When driving the car normally on the street, I cant measure any oil consumption.
As soon as the engine gets hot and a lot of load, the consumption rises badly.
The last time on track my engine used half a liter of oil in one 20 minute stint.
But on the way back home (3h ride on the Autobahn with 160km/h) it used nothing.
We all use different oil types (I am using the Motul 300v 15W50).
My first attempt is to close the PCV valve in the intake manifold.
But I dont think that it can press that much oil through there.
I also tested the valve and it seems to function corretly.
My friend disassembled his engine completely, because he thought his piston rings or valve shaft seals are broken.
But he wasnt able to find anything wrong. The other guy did the same and he also wasnt able to find anything wrong.
So our Idea is now, that the pressure inside the crank case is much too high.
As I found out from Mahle, the piston rings need the pressure of the combustion to press against the cylinder wall and make a good sealing.
But if the pressure in den crank case underneath the pistons is also high, the rings might not be able to seal correctly.
Are the channels from the crank case into the cylinder head too small to let the pressure out?
Do we might need a seperate ventilation?
How do you guys do that with "high power output"?
Do you have the same problems on track?
Thank you guys for your help and very kind regards from Germany!