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techtalk:ih:oil01 [2020/06/05 21:04]
hippysmack [Engine Oil Pressure (57-85)]
techtalk:ih:oil01 [2020/07/21 19:27]
hippysmack [Transfer Valve (76 and earlier)]
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 ====== Transfer Valve (76 and earlier) ====== ====== Transfer Valve (76 and earlier) ======
-The foregoing by Dr Dick ((http://​xlforum.net/​forums/​showpost.php?​p=3886388&​postcount=40))+ 
 +There is only one moving part in the transfer valve assembly which is the triangular shaped disc in the pics below (reed, patel, wafer or whatever you'd call it). \\ 
 +It's a triangular piece of .009" thick stainless steel that can move about .015" left to right in the valve. There is no spring. \\ 
 +In a RUNNING engine, it is a one way valve that lets air and oil pass through it from primary case to flywheel case. \\ 
 +[[https://​www.youtube.com/​watch?​v=EOu0uR2ulF8|Click here]] to see a video of the direction of flow. \\ 
 + 
 +Positive crankcase pressure pushes the reed to the left and seals a small hole preventing flow into the primary. \\ 
 +Vacuum in the crankcase pulls the reed to the right up against a stop that has a larger hole. \\ 
 +The 3 cuts that make the reed a triangle allow air/oil to flow around it into the crankcase. \\ 
 + 
 +Without the engine running and with no spring to maintain a tight seal, oil can slowly leak through and let wet sumped oil pass into the primary. \\ 
 +On engine start up the excess oil in the primary should be transferred back into the engine. \\ 
 + 
 +The thread is 3/​4"​-16. \\ There is nothing to wear out. However anything that stops the movement of the reed (rust or dirt) means the valve won't work. \\ 
 +The one taken apart here was gummed up with old oil that had a tar like consistency. \\ 
 + 
 +{{:​techtalk:​ih:​oil:​transfer_valve_exposed_pic_1_by_needspeed.jpg?​direct&​800|}} ((photo by needspeed of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2077280)) \\ 
 + 
 +Also, as a test, a container of 20w-50 oil at room temperature was allowed to gravity drain from the transfer valve. \\ 
 +It took 48 hours for 100 milliliters of oil to drip through the valve. \\ 
 + 
 +{{:​techtalk:​ih:​oil:​transfer_valve_exposed_pic_3_by_needspeed.jpg?​direct&​300|}} ((photo by needspeed of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2077280)) \\ 
 + 
 +Here are a few drawings detailing the assembly: \\ 
 + 
 +{{:​techtalk:​ih:​oil:​transfer_valve_exposed_pic_2_by_needspeed.jpg?​direct&​500|}} ((drawing by needspeed of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=2077280)) \\ 
 + 
 + 
 +---- 
 + 
 +...... ​The foregoing by Dr Dick ((http://​xlforum.net/​forums/​showpost.php?​p=3886388&​postcount=40))
  
 The transfer valve is staked into position. ((Ferrous Head of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=581947&​page=6)) \\ The transfer valve is staked into position. ((Ferrous Head of the XLFORUM http://​xlforum.net/​forums/​showthread.php?​t=581947&​page=6)) \\