PVC and catch can question

[SDT1DYI]

I wrote to our Divisonal tech director as to installing a Mororso type oil seperator. Was told, not legal for stock if it did not come as an OEM item for the year and make of your vehicle in Stock Eliminator.
Baffles help, but if there's no performance gain, why do this?
The question to answer is , how much vacuum does the motor hold on the starting line and what is it down track?
All the comp guys run one or two vacuum pumps. Increasing crankcase vacuum is proven to make more power.
Benifits are diminished with lower Hg vacuum numbers. Besides ring seal, all the engine gasket sealing surfaces and crankshaft seals effect crankcase vacuum. There are special crankshaft seals designed for vacuum service as well.

Steve Teeter. STK/SS 620

[Ralph A Powell]

I could get a consent 5” with header only on my car. Reason I know is I had a vacuum gage right next to my tach so I could read it all the way down track but the engine was very well sealed ( no vacuum leaks)

[Jeff Stout]

I was hoping for better ring seal and performance. But contaminating the top side I feel is hurting the potentail gain. Looks like the catch can being not legal is answered. Thanks for the replies.

[GTOMayhem]

I understand PCV valves allow varying degrees of vacuum depending on engine application. There is even an adjustable one. Someone with more knowledge than me will need to fill in some details, though. Also, I think Billy Nees just runs a vacuum brake booster check valve as a PCV. He will need to fill in the details.



Rick Thomason
GTO Mayhem

[SSDiv6]

Jeff,

You have options.

You can put a Wix crankcase breather filter, P/N 46978, between the valve cover and PCV or breather.

https://www.wixfilters.com/Lookup/Pa...px?Part=138224

Another option are Speedway Motors PCV Grommet Baffles.

https://www.speedwaymotors.com/PCV-G...Caps,7332.html

Or, weld tubes on the valve covers and put breathers.

[Jeff Stout]

Originally Posted by SSDiv6

Jeff,

You have options.

You can put a Wix crankcase breather filter, P/N 46978, between the valve cover and PCV or breather.

https://www.wixfilters.com/Lookup/Pa...px?Part=138224

Another option are Speedway Motors PCV Grommet Baffles.

https://www.speedwaymotors.com/PCV-G...Caps,7332.html

Or, weld tubes on the valve covers and put breathers.

Thanks Joe. I ordered the grommets from Speedway