Bone Head Question

[Jetty 468]

With your basic bbc 468 10 - 1 around 450hp do I need to run a pcv valve or can I run another breather in that hole ??
Jetty

[Blown 472]

Jetty 468:
With your basic bbc 468 10 - 1 around 450hp do I need to run a pcv valve or can I run another breather in that hole ??
Jetty To me it is a mattter of choice, as I dont spend all of my time at wot, where there is no vacuum so I run on to keep the mess to a min, yes I do have some blow by.

[MikeF]

J468, Go with the breather. A pcv valve does not let much "flow" back into the engine, relieving the pressure inside the block. The flow that will get in there will have oil in it if you run the engine @ higher speeds alot. this will eventually cause oil in the combustion chamber and lead to detonation that you definately don't want. smile_sp

[Blown 472]

MikeF:
J468, Go with the breather. A pcv valve does not let much "flow" back into the engine, relieving the pressure inside the block. The flow that will get in there will have oil in it if you run the engine @ higher speeds alot. this will eventually cause oil in the combustion chamber and lead to detonation that you definately don't want. smile_sp HUmmmmm very good point, I may want to reconsider. Thanks for the info.
But isn't there something to be said for a postive crank case pressure?? or vac.
[ April 03, 2003, 06:40 AM: Message edited by: Blown 472 ]

[MikeF]

Opened up a small can of worms :p .
The PCV is pulled off the N/C position when the engine is creating alot of vacuum (@ cruise)......removing the gasses that get past the rings.
When operating at a higher rpm the more blowby happens and pushes past the closed position of the valve (spring loaded)(no vacuum pulling PCV valve to it's open flowing position)(blowby pushing oil into intake/carb).
idea smile_sp

[Blown 472]

No can of worms, just looking at both sides. Once agian thanks for the info. wink

[MikeF]

Just some light humor :D .

[Essex502]

Last time I was out at the dragstrip most of the cars had a breather on the valve covers attached with a hose to the header collector to provide flow. Must be something to it since them run wide open throttle all the time.
[ April 03, 2003, 07:17 AM: Message edited by: Essex502 ]

[HammerDown]

Hmmmm...so all this time I've been runing a PCV valve in my right Valve cover...I should'nt have? My PCV isnt spring loaded...just gravity weight.
[ April 03, 2003, 09:10 AM: Message edited by: HammerDown ]

[Fiat48]

Essex502:
Last time I was out at the dragstrip most of the cars had a breather on the valve covers attached with a hose to the header collector to provide flow. Must be something to it since them run wide open throttle all the time. What you saw at the dragstrip was a "evacupan" system. The exhaust helps pull a slight vacuum and helps with crankcase pressure and ring sealing. Boats can use it also. Moroso sells a kit or make your own using GM smog valves.

[Jetty 468]

Thank's people , So I don't need to run pcv anymore right ?
jetty

[Hotcrusader76]

The vote is out. No PCV... :D
Hell if ya want to still run it you can always add it back on. Meanwhile keep me posted on your progress.
~Ty

[HOSS]

HHHMMMMMMM! Nah, I`m in too deep in other threads.

[Jetty 468]

Hotcrusader76:
The vote is out. No PCV... :D
Hell if ya want to still run it you can always add it back on. Meanwhile keep me posted on your progress.
~Ty OK then, I will go out and pick up another breather in the morn. Going to go to the lake Sat. for a little test and tune . I will come back with update !