Kissinger_520H 3 #1 Posted July 25, 2023 So I posted this question in another thread and got a few suggested methods of fixing it, but no one actually answered my question of how the oil drain can flop around so loosely but somehow not leak oil? Can anyone illuminate this curiosity of mine? Share this post Link to post Share on other sites
Ed Kennell 41,809 #2 Posted July 25, 2023 That is a tapered pipe thread that relies on the threads to make the seal. There is no gasket or "O" ring. The alternating low pressure to vacumm created by the piston movement in the crankcase does not push the oil thru the loose fitting tapered pipe thread. 1 Share this post Link to post Share on other sites
Handy Don 13,999 #3 Posted July 25, 2023 25 minutes ago, Ed Kennell said: That is a tapered pipe thread that relies on the threads to make the seal. There is no gasket or "O" ring. The alternating low pressure to vacumm created by the piston movement in the crankcase does not push the oil thru the loose fitting tapered pipe thread. Yep. There is adequate “tightness” in the threaded joint that the oil is constrained. One of the oil companies used to advertise oil poured into a cylinder comprised of a simple stack of metal rings where the oil didn’t leak out. 1 Share this post Link to post Share on other sites
squonk 43,744 #4 Posted July 25, 2023 But yet a fairly tight pipe plug will seep oil Share this post Link to post Share on other sites
Handy Don 13,999 #5 Posted July 26, 2023 16 hours ago, squonk said: But yet a fairly tight pipe plug will seep oil A problem that has plagued the pundits for decades.... Share this post Link to post Share on other sites
Wild Bill 633 877 #6 Posted July 26, 2023 The cure for a "Floppy Oil Drain Pipe" is sildenafil citrate otherwise know as Viagra which lasts 4-6 hours or Cialis which lasts up to 36 hours. Pick your pleasure. 1 Share this post Link to post Share on other sites