The Stovebolt Site Forums The Shop Area Engine Shop Loose rocker shaft and broken oil line

During a nice Sat cruise I started noticing the valves getting louder and an intermittent engine miss. Oil pressure was OK for my 49 216 so I turned around and headed back to the homestead. About 8 miles from the house it started missing badly, lacked power to the point it would hardly pull the last hill and the valves were really sounding off. It got me home so I started troubleshooting.
What I found makes it amazing it got me home.
The bolt that secures the 5/6 rocker shaft tower had worked loose enough to where cyl's 5 & 6 were dead. The loud clacking was probably the rockers hitting the valve stems.
The motion of the loose rocker shaft caused the oil feeder line to drop which eventually broke it via contact with a push rod.
I thought I could splice the line but once I removed the side pan I found it was broke at the bend at the soldered connector so it was toast.
Back when I got it running approx 8500 miles ago I thought I'd have to replace that oil line so I had the kit on hand plus a new side pan gasket kit so after knocking out a few chores I decided to tackle it.
5 hrs later I had a running truck again.

I gotta say that getting the oil line attached to the oil distribution fitting behind the exhaust pipe was the most time consuming with getting that big ole side plate back on with all the gaskets in place the 2nd.

I decided to put thread locker on the rocker shaft bolts then torqued them to 30 ft lbs (just like before).

All in all I'm lucky in that it not only got me home but I had the needed parts on hand. No additional damage was observed and my team played one of it's worst games of the year and lost so I didn't miss it much either.

Wonder how much time the old flat rate book would have gave for it?
Dave

Nice! I had the same issue with a 235 years and years ago. It got me home but I thought I had busted something for sure. It would almost stall the engine every other revolution. The intake on #6 was still working sort of, but the exhaust valve was not getting open. So every other time it came around it would stumble hard. Then the intake would open and it would backfire and on it went. Tightened the bolt and ran it for years afterwards. Very forgiving engines these are.

Good to know I'm not the only one

I had the head rebuilt and it was hot tanked & painted by the rebuilder. When I installed the rocker assembly I oiled the threads of the bolts and torqued them to 30 ft lbs per the manual.
Wonder if paint or the hot tank process could have somehow effected the torque readings?
Theres alot of opposing forces at work on that rocker assembly and exact tolerances need to be maintained at all times.
I'll be keeping a regular check on those towers now. Don't want to have to replace that through-block oil line again.....

Dave