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| | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | 1959 235: What is that pipe plug on pass side top, at head, used for? Where does it go into. Is it OK to leave it plugged when using standard, era accessory, cartridge oil filter? Called a bypass filter I think. Which is plumbed in/out on drivers side.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Feb 2004 Posts: 29,809 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,809 | It's an alternate method of getting oil to the rocker arms if the block passages get plugged up. A 3/16" line is run around the back of the engine from the oil pressure port and tapped into that center port in the head. If you're getting good oil flow to the rockers from the internal passages, leave it plugged.
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!
| | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Leave it plugged. Some people do a "cob job" connection of an oil line from the other side of the block (from a by-pass oil filter port) over to that plugged hole. It feeds more oil to the rocker arm assembly. Maybe someone (Pre '68 Dave?) knows the purpose of that hole on the distributor side of the head. | | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | Will leave plugged and examine oil flow to rockers. Bad engineering to admit passages may get plugged. Did they write a TSB or other instructions? Kind of a mixed up era of oiling/filtering/pressurizing.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | The plug is there to plug the port access after it was drilled, to drill from the head bolt, which rocker oil comes up around over to the supply tube of the rocker connector.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | You mean it's a hole so they could stick a drill thru and drill into a bolt? Don't get your post? "to drill from the head bolt"? Sorry, I'm slow here.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
| | | | | Joined: Jan 2001 Posts: 5,337 'Bolter | | 'Bolter Joined: Jan 2001 Posts: 5,337 | Part of the path the oil takes to get to the rockers is up around the outside of the center head bolt on the passenger side. Chev needed to create a path from that head bolt galley over to the spot where the rocker connecter tube connects to the head. The only way to do this is to drill in from the outside of the head, through the head bolt galley continuing over to the vertical port that the rocker connecter tube fits in. After this drilling process the outer hole needed to be plugged.
See the USA in your vintage Chevrolet! My Blog | | | | | Joined: Oct 2006 Posts: 9,671 'Bolter | | 'Bolter Joined: Oct 2006 Posts: 9,671 | Same thing as cross drilling internal passages in carburetors
then plugging the entrance hole.
dg
Denny G
Sandwich, IL
| | | | | Joined: May 2005 Posts: 8,983 Sir Searchalot | | Sir Searchalot Joined: May 2005 Posts: 8,983 | Now I get it. Thanks everyone.
Right is right, even if everyone is against it, and wrong is wrong, even if everyone is for it. - William Penn
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