What Is Acceptable Crankcase Suction
#11
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We were one of the first to run vacuum pumps in B class. I use them all the time when the customer can afford to run them. Horsepower gains on a N/A engine we have seen as much as 40 depending on how much Vac. is being pulled on the crankcase. With my drag race engines I pull as much as 40 inches. ( such as Pro Stock)
#12
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help me out here .... one belt driven pump ...the motors are tied together via rear valve covers ... I see the pop-off valve on the starboard side of the valve covers then on the port side looks like regular breather ? ... Are we talking mega HP motors here or is there an advantage for 550-600hp ? m
#13
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In these pictures the pop-off valves are on the SP and PS VC. The vacuum contol valves (holds vacuum @ max level by leaking air) are on the SP and PP VC. As rigged, you only really need one of each valve.
In my experience/testing, there is no significant HP gain with a vacuum pump up to 6800 RPM with standard tension oil rings.
Why do it?...you wouldn't if +HP is your primary goal.
In my experience/testing, there is no significant HP gain with a vacuum pump up to 6800 RPM with standard tension oil rings.
Why do it?...you wouldn't if +HP is your primary goal.
#14
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What do you think of using a 5 stage dry sump pump that pulls 10 - 11"@ 6,000... Piston sprayers to lubricate the walls and cool the bottom of the pistons, DLC coated wrist pins, Valve spring sprayers and Lifter sprayers ? Oil pan w/ Nascar screens on each pickup line and a valve on top of each valve cover, capped and shrouded w/ a Moroso screened cap ? The valve is to close with vacuum and open w/ 2 - 3 oz. of positive pressure. At RPM the valve closes as vacuum is introduced and @ low idle may open, subject to ring clearance. While one valve would suffice, two valves are thought to flow volume that should accommodate a burned piston. Thus, safe guarding against a pressurized explosion in the pan. The MILITARY SPEC valve is designed to be trouble free for an extended period of hours.
The oiling /vacuum system may also stabilize piston rock, scavenge oil causing, parasitic drag ,oil aeration and add horsepower. Oil pressure stabilization may also be improved.
The oiling /vacuum system may also stabilize piston rock, scavenge oil causing, parasitic drag ,oil aeration and add horsepower. Oil pressure stabilization may also be improved.
#15
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Rob,
These 2 pics show the vacuum pump system. The rigging is one-off that we have been polishing in for three seasons. The top view shows the hose connecting the engines at the rear of the valve covers. The front VC fitting on the outside allows you to adjust the max vacuum and the inside "breather" isn't really a breather but it is a pop-off valve to vent pressure in case of a system failure. The catch can separates the oil/air and the 3" black flex hose is connected to a side vent on the out side. The pump RPM ratio is at about 45%.
We have actually made a slight rigging change last winter where the adjustable vacuum level fitting is now mounted right at the pump inlet...new Moroso part...looks cleaner.
These 2 pics show the vacuum pump system. The rigging is one-off that we have been polishing in for three seasons. The top view shows the hose connecting the engines at the rear of the valve covers. The front VC fitting on the outside allows you to adjust the max vacuum and the inside "breather" isn't really a breather but it is a pop-off valve to vent pressure in case of a system failure. The catch can separates the oil/air and the 3" black flex hose is connected to a side vent on the out side. The pump RPM ratio is at about 45%.
We have actually made a slight rigging change last winter where the adjustable vacuum level fitting is now mounted right at the pump inlet...new Moroso part...looks cleaner.
#16
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also ive read to only pull 15 inches or less or could have oiling issues ? Do you run a vacumm Gauge on the dash to see / make sure youre vacumm stays below this amount very interested rigging looks good !!
Last edited by ROB FREEMAN; 12-05-2007 at 05:48 PM.
#17
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If you are using a standard tension ring pack, decide how much you are spending on a vacuum system for maybe +5 HP. A dry sump oil pump system also adds little to no additional HP with a lot of cost. I think good oil control can be obtained with a well designed wet sump system for a lot less $$ at a 6000-6500 RPM max operating range.
What you are proposing/doing is top shelf...just expensive
What you are proposing/doing is top shelf...just expensive
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