29 replies to this topic

[alanoo]

You should really start by enlarging the original cam cover vent hole before going to more complicated setups.

 

Also, I'm sure you checked, but the oil level tube can definitely get out of its hole under high boost levels with some going into crankcase.

Edited by alanoo, 15 October 2020 - 09:50 AM.

[FabianG]

Hey guys, 

I think I have the solution. 

I tried a lot of things. I even modified the oil cap (for refilling) to measure the pressure and let as much gas out as possible. 

But it seems that there is always too much oil fog in the gases. 

I unmounted the oil sump and filled in 5 liters of oil on the table. 

As you can see, the sump is very full with 5 liters: 

 

 

I tried to fill 6 liters in, but thats not possible.

When you compare the position of the crank case, you can see that the "vents" under the crankshaft would sit below the oil level.

 

 

That means, that all Gases have to be pushed through the oil and that it takes a lot of oil with it. 

I think I always had too much oil filled into my engine. For now I dont fill more than 5,5 liters (1/4 on the disptick) into it. 

Another thing is, that all the gases have to travel through the chain housing. Imagine the chain spinning wiht 7000rpm and being sprayed by an oil nozzle. 

Thats is the second problem, where all the oil fog comes from. 

 

I opened the plug on the engine block, where normally the oil-return of the turbo charger is connect. (B207)

I mounted a pipe with 16mm inner diameter and connected it to the rest of the venting system. 

 

 

 

 

In the right red circle you can see the T-piece, that connects that hose. 

From there it goes into the oil catch can and from there into the intake pipe. 

I tried to connect it to "vacuum", but then the engine makes strange sounds. 

I think the pressure is much too low and the engine sucks air from some sealing (maybe crankshaft sealing). 

But that configuration works fine now. 

 

I tested it for 400km on the street. I pushed the car as much as possible. 

Normally the oil catch can was completely full after 500km and I burned even more. Refilling the oil was necessary.

 

 

Now it is completely empty except from some condensation and it seems that the engine used no oil at all.

I have a really good feeling about this. But to be a 100% sure I will have to make a test on the track. 

 

I know its not the most beatuiful solution but its just for testing. If that works for the rest of the year, I will make it "beatuiful" and perfect in the winter. 

 

The car even pulls a little better. Now It makes 410HP instead of 400HP. 

Maybe thats a side effect of burning less oil under full throttle. 

 

 

Edited by FabianG, 10 April 2021 - 05:08 PM.

[blackoctagon]

This is quite funny - I was working on the same thing today. And I came to the same conclusion on using the turbo drainback port, except with a full flexible hose and not a hard pipe.

[Exmantaa]

Hey guys, 

I think I have the solution. 

I tried a lot of things. I even modified the oil cap (for refilling) to measure the pressure and let as much gas out as possible. 

But it seems that there is always too much oil fog in the gases. 

I unmounted the oil sump and filled in 5 liters of oil on the table. 

As you can see, the sump is very full with 5 liters: 

 

 

 

Is that the Z22SE sump, or the bigger capacity B207/LSJ sump?

 

[FabianG]

Thats the B207 sump. 

[Exmantaa]

Ok, identical to my US-LSJ sump then.

 

I don't have much oil consumption issues on track, but I do never fill it more than the bottom of my custom dipstick as I measured that to read ~5.4ltr (5.7 quarts), which is the GM specification for the US-LSJ engine.

 

But your big vent pipe is interesting and maybe a solution for track oil consumption. (But I would put some kind of oil separator in that vent route)

 

 

 

[C8RKH]

Hey guys, 

I think I have the solution. 

I tried a lot of things. I even modified the oil cap (for refilling) to measure the pressure and let as much gas out as possible. 

But it seems that there is always too much oil fog in the gases. 

I unmounted the oil sump and filled in 5 liters of oil on the table. 

As you can see, the sump is very full with 5 liters: 

 

 

I tried to fill 6 liters in, but thats not possible.

 

 

 

 

 

 

 

 

 

 

5ltrs of oil cold in the sump, when heated for use, will be what 5.5-6ltrs of oil in the engine - my understanding is that when engine oil is "heated" it can expand in volume by as much as 10%.  I learnt this through understanding why some dry sump engines fail due to over filling with oil as the volume can often be tested "cold" when in fact you need a warm engine and some pressure to actually test the oil levels.  During this research is where I learned the volume of warm/hot oil could be at least 10% higher than it's cold level.

[FabianG]

Except from the filling of the sump, I always measure the oil level at the gas station when the engine is warm or hot. 

There goes a lot of oil into the channels and the pump. I am measuring more oil when the engine is cold for a few days, because all the oil can seep into the sump. 

 

For now I have 1/4 on the dipstick scale when the engine is warm and 2/4 when its cold. 

And that corresponds to 6 liter (with oil filter change).

 

I also found out that the disptick of Z22SE and B207 have different lengths. Thats maybe a problem too. 

 

[FabianG]

 

Top Z22SE, bottom B207.

 

Imagine you have the wrong dipstick in your sump.... 

Edited by FabianG, 12 April 2021 - 11:17 AM.

[Exmantaa]

 

Top Z22SE, bottom B207.

 

Imagine you have the wrong dipstick in your sump.... 

 

I have a (real old) post somewhere about dipstick issues...

 

Do hope you solved your oil consumption with this solution on high power (track) use, as there are a few others that suffer from this.