Crankcase breather
08-02-2012, 01:20 PM
#4
Rennlist Member
Based on reading on the forum, it looks like it is something that would add a few horsepower, but "might" create more leak? I wish there's more definitive answer to this one.. as it would be cheapest horsepower mod for our cars no doubt.. ($100 or so.. for 5hps?!)
08-02-2012, 01:56 PM
#5
Rennlist Member
Thread Starter
Waiting for it. Don't think it'll be put in time for next trackday. If it comes in tomorrow I got a chance since motor has been dropped for intake plenum hose(s) replacement. I have every major leak(coolant/fms) so far cept for rms. Let u guys know when I do a track weekend. Mike
08-02-2012, 04:37 PM
#6
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Can anyone explain the benefit? Most lines these are installed on are the EGR, which is usually tied back into the intake path (low vacuum) and the fumes are burned; its typically an emissions control. Where is the HP?
08-02-2012, 04:50 PM
#7
Rennlist Member
This link is for motorcycle engine, but the theory should be the same:
http://www.ducati-upnorth.com/tech/breather.php
Crankcase Ventilation
Crankcase ventilation is used for three reasons:
It reduces crankcase pressures to nearly atmospheric pressure in order to avoid oil leaks from seals and gaskets.
It reduces crankcase pressures at the bottom of the pistons to provide an increase in the differential pressure across the piston compression rings, and consequently provide an increase of torque and horsepower. A larger differential pressure across the piston oil rings also aids in control of oil consumption.
It reduces pumping losses. In a running engine, the size and shape of the crankcase boundary changes with the movement of the pistons. Ventilating the crankcase reduces parasitic horsepower losses involved in compressing and moving this air volume about, so net power output is increased.
The larger the crankcase volume, the less-compressed the gases it contains become, so the lower the losses. If you vent directly to the atmosphere - through a sufficiently large vent hole - the crankcase can’t attain positive pressure, even at the highest engine rpm. Further, if you create a vacuum in a crankcase, the effect on pressures is the same as increasing the crankcase volume.
It’s interesting to note that in the automobile performance world that there have been performance gains using crankcase ventilation systems that create a vacuum in the crankcase using pumps and extractors.
http://www.ducati-upnorth.com/tech/breather.php
Crankcase Ventilation
Crankcase ventilation is used for three reasons:
It reduces crankcase pressures to nearly atmospheric pressure in order to avoid oil leaks from seals and gaskets.
It reduces crankcase pressures at the bottom of the pistons to provide an increase in the differential pressure across the piston compression rings, and consequently provide an increase of torque and horsepower. A larger differential pressure across the piston oil rings also aids in control of oil consumption.
It reduces pumping losses. In a running engine, the size and shape of the crankcase boundary changes with the movement of the pistons. Ventilating the crankcase reduces parasitic horsepower losses involved in compressing and moving this air volume about, so net power output is increased.
The larger the crankcase volume, the less-compressed the gases it contains become, so the lower the losses. If you vent directly to the atmosphere - through a sufficiently large vent hole - the crankcase can’t attain positive pressure, even at the highest engine rpm. Further, if you create a vacuum in a crankcase, the effect on pressures is the same as increasing the crankcase volume.
It’s interesting to note that in the automobile performance world that there have been performance gains using crankcase ventilation systems that create a vacuum in the crankcase using pumps and extractors.
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08-02-2012, 07:09 PM
#8
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08-02-2012, 08:07 PM
#13
Race Car
I thought about this mod while I had mine apart but decided to stay cautious and not do it.
Almost wish I woul have in looking back but oh well. I do all my own mechanical work and can tell you there's no amount of money that would make it worth me installing the breather now that the car is back together
Almost wish I woul have in looking back but oh well. I do all my own mechanical work and can tell you there's no amount of money that would make it worth me installing the breather now that the car is back together
