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Crankcase evacuation valve in Downpipe?????

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1QWIK6

Torque wins
Joined
May 24, 2001
Messages
7,567
I was thinking of putting a Crank Case evacuation vavle (found on drag cars) on my downpipe. Has anyone done this? Is it possible on a street car? I run a 3"TH D/P and a single shot 3" exhaust.
 
Forget it, not enough exhaust gas velocity in the DP for it to be effective. You would need a evac pump for this. Contact Ramchargers if you want to find out about a pump kit.
 
I have one..in my budget 3" down pipe...it pulls from the pass side v cover...it works for me! later:cool: joe
 
Are you sure? If you run a single 3" straight shot muffler and no cat, wouldn't that be near the same as open headers (i.e. little to no backpressure). The other problem with runnin a belt system setup is no one makes a setup for the serpentine style belts.
 
The turbo itself knocks the heck out of exhaust velocity in the DP. Not to be a jerk Joe, but what kind of vac readings do you get to verify how well it works? You would need to tap into the valve covers with a line to verify this.

Guess we really have 2 different scenerios with an evac system, one for street use to "help" the PCV, other race set up to evac crankcase pressure.

The DP type may help the PCV, but does little for crankcase pressure at high RPM's.
 
my car has no pvc...I welded the hole on the intake closed!..for me it was a "wonder if this would work" project!..I have not mesured the amount of vaccuum witha guage ....but at idle I can here the asperator valve chirping!.somthing is pulling the valve open....and with NO vaper coming from the oil fill breather...i would think that it has alot to do with how and were the asperator valve is plumed in the exhaust system....joe
 
Joe, I would really like to knowin how well your system works? If you could tap a vac line into a valve cover and seal the oil fill hole that would be a good test. I have some spare valve covers and a vac gauge that I would be willing to send you [and reimburse for return postage] if you are interested?
 
A friend on mine has a header evac system after on his twin turbo Northstar engine. Works real good on that. Its hard to pull the oil fill cap off with the engine running. I'm not sure what the vacum in the crackcase is, but its working very well. He's still running the stock PCV. I'll be trying it eventually.
 
I run an evac system from both valve covers beacuse I have a sheet metal intake. Works great!! Drive it on the street too.
any doubt, call Conley
Jim
 
DUZ IT WURK??

You can tell if the crank evac system works really well when the wrist pins lock up !!:eek: :eek:
20 to 23 in vac on a good prostock engine.
17 to 19 on a comp eliminator engine.
8 to 12 on a stock type engine.
All this wisdom from the gurus at Stefs Oil Pans.

If you are going to pull some serious vac on the crankcase, the wrist pins should be coated, etc, to compensate for less oil. Pin oilers should be drilled into the pistons and if the pins are full floating, the top of the rod drilled for pin lube.;) ;)
 
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