My build taken to the next level *701WHP/450TQ*
12-25-2008, 05:31 PM
#111
Originally Posted by tony1' date='Dec 22 2008, 09:19 AM
You can make lots of power with very little ventilation, but that doesn't mean it's ideal. Have you ever datalogged crankcase pressure?
We've found that at big power the engine benefits from additional ventilation. Once the engine is built, it's usually even more important because the clearances are generally bigger than the stock engine.
We've found that at big power the engine benefits from additional ventilation. Once the engine is built, it's usually even more important because the clearances are generally bigger than the stock engine.
12-26-2008, 05:56 AM
#113
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Originally Posted by Spoolin' date='Dec 25 2008, 06:31 PM
I haven't data logged crankcase pressure but I'll check it out to see where it is. What is a safe crankcase pressure and what is not?
Crankcase pressure will cost you power, possibly blow oil seals and dipsticks out if it's enough, and often make your turbo smoke because it can't drain properly into a pressurized oil pan.
12-28-2008, 04:02 PM
#114
Originally Posted by tony1' date='Dec 26 2008, 09:56 AM
I wouldn't say there's a safe number and a not safe number, but lower is always better. In a perfect world you'd pull a vacuum in the crankcase as many high end race cars do. Much more realistic for us though is keeping things at atmospheric pressure, which can be done with adequate venting.
Crankcase pressure will cost you power, possibly blow oil seals and dipsticks out if it's enough, and often make your turbo smoke because it can't drain properly into a pressurized oil pan.
Crankcase pressure will cost you power, possibly blow oil seals and dipsticks out if it's enough, and often make your turbo smoke because it can't drain properly into a pressurized oil pan.
Thanks for the help.
12-29-2008, 01:50 PM
#115
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Originally Posted by Spoolin' date='Dec 28 2008, 05:02 PM
I do have a Krankvent at my PCV valve that also runs to a small catch can (its an air compressor water catch but works well) and back to the intake manifold. I also have a Krankvent from my front stock valve cover port that runs to my turbo intake so that I do have vacuum on it. Do you think this is adequate enough for over 600 whp? Again, I haven't had any problems in over a year but I'll still log the pressure when I can. I'm just curious if I'll be fine the way I have it.
Thanks for the help.
Thanks for the help.
Anything going back to the intake manifold is worthless in a forced induction application. You can't bleed crankcase pressure into a pressurized intake manifold.
Going to the intake of the turbo is better, but without a catch can inline or a really good baffled valve cover, you are likely to pull some oil into the turbo inlet, which you don't want. You're not going to pull a vacuum on the crankcase with this method.
I would take both of your vents from the valve cover and run them into a filtered catch can and leave them breathing to atmosphere.
