I could figure out my own question but this would require me to remove my ODV (Oil Distribution Valve) plus purchase and replace 2 gaskets and pay shipping. It's cheaper to ask.
Please find the question mark in the attached picture. Where is the small hole going to in the block? Example, is it going directly to the oil passage or is it also shared with pipe connection going to the rocker arm assembly? Hopefully someone has a junk block that's easy to get to. Close-up (macro function) pictures would be fantastic. Thanks.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM."
That passage is drilled to connect to port #2, and supplies oil to the "through the water jacket" tube to the rocker arm shaft when the spring loaded valve in the oil distributor plate opens. Any excess volume will be bypassed back to the oil pan through port #4. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
The #2 port is the output to the rocker arm shaft- - - -it gets there via the copper tubing that transits the block through the water jacket. It does not connect to the main and cam bearing oil galleries at all. The hole in the block you asked about is on the output side of the oil distributor- - - -the only time it receives oil is when there's sufficient pressure in the main and cam bearing passages to push the spring loaded plunger off its seat. This setup prioritizes oil flow to the lower end of the engine- - - -shutting off flow to the rockers whenever there's a pressure drop in the main/cam bearing circuit- - - -idle, and/or excessive bearing wear. It's like the human body's circulatory system- - - -sacrificing extremities to keep blood flowing to the body's core. Rocker arms don't need a lot of oil- - - -just enough to keep a thin film of oil on the bottom of the rockers is plenty. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
