CLASS RACER FORUM - View Single Post - One way valve at collector for evacuation system

MAURICE BLENDHEIM · 03-24-2018, 09:14 AM

What we have found with these common check valves is, they require more vacuum and more crankcase pressure to move internal valve off the seat. In their original form they are designed to stop exhaust back pressure from entering air injection system. An air injection system develops a higher pressure than what your crankcase pressure "should not be". The header vacuum signal also is in most cases is not high enough to move valve off the seat either and back pressure in an open header application has as close to zero back pressure as you can get. These check valves actually work when you hollow them out with a drill. Your crankcase pressure is then evacuated through those relatively restricted breathers in the rocker covers, through the 3+ foot long 5/8" hose connected to the check valves that are mounted to the 1/2" NPT nipples that are 3-4" long that has one end cut on a 45 degree angle with an orifice cut into it, scientifically positioned into the collector that develops a very "low to no" vacuum signal, to create an evacuation atmosphere or a complex "road draft" system. Check it out and see what I mean. I stand to be corrected. Maurice.

03-24-2018, 09:14 AM	#9
MAURICE BLENDHEIM Senior Member Join Date: Jun 2011 Location: Langley (no igloos), British Columbia, Canada Posts: 569 Likes: 311 Liked 285 Times in 87 Posts	Re: One way valve at collector for evacuation system What we have found with these common check valves is, they require more vacuum and more crankcase pressure to move internal valve off the seat. In their original form they are designed to stop exhaust back pressure from entering air injection system. An air injection system develops a higher pressure than what your crankcase pressure "should not be". The header vacuum signal also is in most cases is not high enough to move valve off the seat either and back pressure in an open header application has as close to zero back pressure as you can get. These check valves actually work when you hollow them out with a drill. Your crankcase pressure is then evacuated through those relatively restricted breathers in the rocker covers, through the 3+ foot long 5/8" hose connected to the check valves that are mounted to the 1/2" NPT nipples that are 3-4" long that has one end cut on a 45 degree angle with an orifice cut into it, scientifically positioned into the collector that develops a very "low to no" vacuum signal, to create an evacuation atmosphere or a complex "road draft" system. Check it out and see what I mean. I stand to be corrected. Maurice.