Wicked
03-05-2005, 05:26 PM
Well,
I debated on whether to post this as I always get flamed for doing something that noteveryone else has done.
We had talked before about crankcase ventilation and I showed you guys my separator and how ugly ass it was. :jester:
Well it fills up too quickly and I smell gas when I'm sitting still. So it had to go.
I found a way to use engine vacuum(throttled of course) to evacuate the crankcase and eliminate crankcase pressure and venting of the crankcase gases.
So here's the basic idea. I'm sure you know simply evacuating the crankcase with engine vacuum will suck air past the seals and is not a good idea and actually causes stange noises. So what I did was harness the vacuum and throttle it to a acceptable level.
I used a swagelok valve, a vacuum brake booster check valve, and the stock pcv valve.
On the driver side, I have the valve right at the vacuum port. It limits the flow out of the crankcase and will effectively limit the maximum vacuum level in the crankcase. The PCV valve in the drivers head prevents boost from leaking into the crankcase during WOT blast.
On the passenger side, I have a breather filter and a check valve that only allows flow out of the breather but not into. Notice the bulge in the hose in the pic. Thats the brake booster check valve.
So I with the valve fully closed I started the car and gradually opened the valve to find the point where the seals started leaking and making noises. I then throttle back some to find an acceptable vacuum level. In my case it was about 4 inches of mercury.
So under part throttle, intake vacuum condtions, the crankcase is seeing negative pressure. This is better for ring seal.
Under WOT, gases are still vented. But considering the time I spend at part throttle versus WOT this will work for me. It may not work for everyone and it is definitely not a fix if you have the old oil in the intake problem.
I'll let you guys know in the coming days how it goes with this new setup.
I debated on whether to post this as I always get flamed for doing something that noteveryone else has done.
We had talked before about crankcase ventilation and I showed you guys my separator and how ugly ass it was. :jester:
Well it fills up too quickly and I smell gas when I'm sitting still. So it had to go.
I found a way to use engine vacuum(throttled of course) to evacuate the crankcase and eliminate crankcase pressure and venting of the crankcase gases.
So here's the basic idea. I'm sure you know simply evacuating the crankcase with engine vacuum will suck air past the seals and is not a good idea and actually causes stange noises. So what I did was harness the vacuum and throttle it to a acceptable level.
I used a swagelok valve, a vacuum brake booster check valve, and the stock pcv valve.
On the driver side, I have the valve right at the vacuum port. It limits the flow out of the crankcase and will effectively limit the maximum vacuum level in the crankcase. The PCV valve in the drivers head prevents boost from leaking into the crankcase during WOT blast.
On the passenger side, I have a breather filter and a check valve that only allows flow out of the breather but not into. Notice the bulge in the hose in the pic. Thats the brake booster check valve.
So I with the valve fully closed I started the car and gradually opened the valve to find the point where the seals started leaking and making noises. I then throttle back some to find an acceptable vacuum level. In my case it was about 4 inches of mercury.
So under part throttle, intake vacuum condtions, the crankcase is seeing negative pressure. This is better for ring seal.
Under WOT, gases are still vented. But considering the time I spend at part throttle versus WOT this will work for me. It may not work for everyone and it is definitely not a fix if you have the old oil in the intake problem.
I'll let you guys know in the coming days how it goes with this new setup.