dry sump motor ?

[idahon]

sbc turbo. 5 stage dry sump oiling i have 1 in the lifter valley 3 in the pan. what do i do for a vacuum relief ? do i just put a breather in a valve cover? do i use a fancy regulator like Peterson sells? if i use the regulator what do i set it @? will i have any issues when the crank case goes from vaccuum to boost (i would assume that you will have positive pressure in the crank case)

[Robert1320]

http://www.petersonfluidsys.com/Photos/5stgdia.jpg

[Robert1320]

More than likely even with all this you will still need a Vacuum pump to actually get vacuum.

[Robert1320]

If you are going down the Vacuum pump road.
Use a Star Machine pump and always place the vacuum requlator at the pump.
This will allow cool air to enter the pump and increase its life.
Last draw the crankcase air though a separator or catch can before the pump and vent to a filter. This will keep excessive amount of oil out of the pump.

[idahon]

here is the issue.........my pump sucked the front gasket into the pan. this is why im asking if anyone runs a vac relief.

[Robert1320]

Put a gauge in the cover and check for vacuum.
If you got too much you'll need regulator.

[idahon]

how much is 2 much?

[niceguy]

More than likely even with all this you will still need a Vacuum pump to actually get vacuum.

Moroso claims that my 4-1/2 stage Prostock dry sump pump will actually pull up to 25" of vacuum. I'll be able to tell you for sure in a couple of days.

I think 12" of vacuum is plenty. I have a relief valve in my valve cover just incase. You can get a fairly cheap one at a couple places.

[Robert1320]

8-12 inches should be enough.

[383Malibu]

We have a Barnes 6 stage dry sump in our 381"sbc (N/A) with a break valve (regulator) in the valve cover and no additional vacuum pump. The break valves that install at the pump are a better solution, we just happened to have a Moroso (valve cover type) available. The engine is well sealed and, with the break valve set at 18", it holds 18" from just over idle to full song. We've never built a turbo motor, but any N/A motor that didn't have pin clearances adjusted for vacuum use probably shouldn't use more than 12" vacuum.

[ProF100]

What should the pin clearances be for NA with 18" of vacuum? I have a 5 stage on a 640" BBF and it is still not too late to open the clearances up. My pins are very close fitting now. Probably .0005" clearance now.

[383Malibu]

With 18" vacuum, I'd run at least .0014". BTW, some NHRA Pro Stock teams are running .002"+.