- #1
seijirou
- 4
- 0
Hi,
I know a little about a little and nothing about a lot, but I've got an idea and I thought this community may be able to lend a hand. Perhaps even find it interesting, who knows.
I'm working on a race car, and I need to deal with pressure that can build in the crankcase because piston rings don't seal perfectly.
Typically the crankcase pressure is vented through a tube back into the intake behind the throttle plate and thereby recirculated. That is not an option on this car as the vented pressure contains an oily mist which reduces the effective octane rating in the combustion chamber, and this is very unhealthy for race car engines.
A common alternative is to simply vent the crankcase to atmosphere. In time however this smothers that oily mist all over everything under the hood, and generally makes a mess.
A more enterprising idea is to use a vacuum pump to draw pressure from the crankcase. Unfortunately it's also a rather expensive idea to purchase a pump for this purpose. Some have tried to re-purpose smog pumps (exhaust air injection pumps) but they are designed to run dry. So when their innards are exposed to that oily mist, they shortly fail.
Now here's my hair-brained idea. Rather than using a smog pump directly as a vacuum pump, use it to blow through tubing. Step down the diameter of the tubing after the smog pump to create a venturi effect, and provide a tap at the choke point where from a line can be run to the crankcase. Finally terminate the run of tubing into the exhaust system.
Here's a picture that I whipped up.
Would it work?
Thanks
I know a little about a little and nothing about a lot, but I've got an idea and I thought this community may be able to lend a hand. Perhaps even find it interesting, who knows.
I'm working on a race car, and I need to deal with pressure that can build in the crankcase because piston rings don't seal perfectly.
Typically the crankcase pressure is vented through a tube back into the intake behind the throttle plate and thereby recirculated. That is not an option on this car as the vented pressure contains an oily mist which reduces the effective octane rating in the combustion chamber, and this is very unhealthy for race car engines.
A common alternative is to simply vent the crankcase to atmosphere. In time however this smothers that oily mist all over everything under the hood, and generally makes a mess.
A more enterprising idea is to use a vacuum pump to draw pressure from the crankcase. Unfortunately it's also a rather expensive idea to purchase a pump for this purpose. Some have tried to re-purpose smog pumps (exhaust air injection pumps) but they are designed to run dry. So when their innards are exposed to that oily mist, they shortly fail.
Now here's my hair-brained idea. Rather than using a smog pump directly as a vacuum pump, use it to blow through tubing. Step down the diameter of the tubing after the smog pump to create a venturi effect, and provide a tap at the choke point where from a line can be run to the crankcase. Finally terminate the run of tubing into the exhaust system.
Here's a picture that I whipped up.
Would it work?
Thanks