List,
It has occurred to me that if part of the purpose of a dry sump or
vacuum pump system is to rid the engine of foam caused by blow-by,
then a good set of rings should be beneficial with a regular comp oil
pan with scraper, tray, etc. wouldn't it? Then the blow-by/foam would
be reduced and along with it the need for the dry sump system.
I use a tool steel Dykes top ring and a zero-gap second ring with a
standard rail oil ring.
I have no blow-by to speak of on a twin turbo BBC (12 lbs boost/gas)
and the oil pressure is stable....so far. HP should be in the
1200-1400 range. Leak-down is 5% +/- 1% after 6 license level runs.
Bearings are good and oil pressure has been bumped from 60 psi to 75
psi. Can't wait 'til next year!!!!
Skip
At 10:07 AM 10/25/2006, Ed Weldon wrote:
>Mayf and all--
>Lots of "he said, she said" stuff has flown around on this subject; but not
>much in the way of verifiable and credible numbers. I think the best most
>of us can do is listen to the wisdom of the subculture and go from there.
>I'll go dry sump as soon as I think the benefits outweigh the costs.
>Perhaps my decision making process will weigh a little more heavily on the
>numbers. But that's just the critical thinking engineer in me. That
>approach isn't necessarily for everyone. I do have a lot of respect for the
>wisdom out there............
>On horsepower figures I doubt that the pump makers have a lot of good data
>on horsepower gains. They probably have rating curves on the pumps. This
>info can be developed from classic texts on the subject and some test data
>to verify the calculations. They also likely will share glowing
>testimonials from a few customers that were willing to share their dyno
>data. I'd approach this latter stuff with the critical eye you use on most
>advertising.
>Hmmm...67 ft/second. That's 45mph. Stick your hand out the car window in a
>good rainstorm at 45 mph..................Yup, I know; you'll get soaked in
>the name of science.....
>Anyone interested in how to interpret a rating or test curve on a gear pump
>and adjust it to fit a different set of conditions like rpm, oil viscosity,
>specific gravity and pressure.........Be glad to tell you what I can.
>Ed Weldon
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