Earlier tonite, myself and a friend were flow testing(sf600) a V-8 cylinder head on an old block that is all sealed up, pulling vacuum through a bung which is welded into the oil pan and noticed a difference (gain) of approx. 18 cfm from prior tests which were done on the bench it self. At first we thought we had a leak some where, but after double sealing every possible leak with duct tape the results were identical. Next we took the superflow calibration orifice and set it up on the bench, as well as set it up over a cylinder in the block and this test also confirmed the same, an 18 cfm gain on the block. Next we sealed the calibration orifice to the engine block end of the hose, (now just bench and hose being compared) and yet again same results.We are kinda baffled, a person would think that it would be just the oppisite, considering we are connecting the two through a four inch hose about 6ft long. Any thoughts from you guys???
Could it be due to the additional volume of the chamber(hose), or could we be experiencing laminar flow at 25" wc and around 240 cfm?? Thanks in advance.....RRBD