FWIW - when I was putting together my 600hp street/strip motor I spoke to David Butler and asked his opinion on a street EVAC pump. He recommended the base kit they sell. It is a remanufactured Ford pump (?) with a Moroso pulley, -12 lines and I used the Moroso valve cover adapter.
While on the dyno we hooked up the manifold pressure line to measure crank case vacuum. My readings were as follows...
RPM inHg
1500 -1.5 this what I recall at idle
The dyno run sheet showed the following
3000 -2.9
3500 -3.1
4000 -3.7
4500 -4.2
5000 -4.7
5500 -5.4
6000 -6.1
6300 -6.8
I didn't use the system to pick-up any real HP...I'm using it for better gasket sealing and a cleaner intake charge. Incidentally vacuum signal got stronger as the pump broke in.
Also, there was a interesting HPP article about a month back that can answer additional questions.
Hope this helps.
Dan
Last edited by GTO Dan; 02-06-2007 at 09:48 PM.
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