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Old 03-09-2012, 03:44 PM   #1
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Now, that being said.. drag racers for years have used a belt driven vacuum pump to pull upwards of 20inches of vac on the engine at high rpm (non dry sump engines)

GT3 = dry sump
9X6 = wet sump
9X7 = wet sump

Want to run a breather can? Go to a belt driven vac pump and adjust the suction side of the pump so it does not pull too much vac on the engine causing seals to collapse.


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Old 03-09-2012, 04:04 PM   #2
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Originally Posted by Brad Roberts View Post
Now, that being said.. drag racers for years have used a belt driven vacuum pump to pull upwards of 20inches of vac on the engine at high rpm (non dry sump engines)

GT3 = dry sump
9X6 = wet sump
9X7 = wet sump

Want to run a breather can? Go to a belt driven vac pump and adjust the suction side of the pump so it does not pull too much vac on the engine causing seals to collapse.


B
Hmmm. That may be a little more complicated than I had in mind.

Thanks for the explanation regarding vacuum. Was not aware of this. Isn't that the reverse of the old fashion PCV (positive crankcase ventilation) that so many of my early cars featured?
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Old 03-09-2012, 04:18 PM   #3
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Bingo @PCV

Porsche has known for a long long time that pulling a vacuum on the engine was a good thing. Most european car companies do this, it wasn't until the late 90's the "merican" car companies figured it out.

PCV's pull vacuum on the engine, but it was not what we call "plenum or port vacuum" it was a simple line from the PCV to the air cleaner.

New LS GM engines have a version of our AOS on them.

12k RPM VW drag engines will make 3-4hp *more* with a belt driven pump


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