The Stovebolt Site Forums The Shop Area Engine Shop What happened to this tube?????

Worked on the '51 half ton project this week. I bought it knowing the engine was not running. Pulled the plugs and they all looked great. No oil! Decided to pull the valve cover off and look inside. Everything looked nice and tidy with no thick oil crud deposits. Basically clean. Just as I was about to put the cover back on I noticed the oil tranfer tube between #3 and #4 cylinders was damaged. Upon closer inspection I realized that it had been cut in two pieces!! I immediately assumed it had been caught in the rockers somehow and was pinched in two pieces. Looking closer I saw I could remove the piece that has a narrow tip and goes down into a hole leading to the oil galley. I pulled it out and realized it had been cut by someone. I could see plier marks! I guess that the previous owner did this, but why I do not know. I would also like to know if this will allow adequate oiling of the 216 once I ever get it running again?

Thanks for the help solving this mystery.

sounds like the tube that just runs back into the lifter gallery. they just run into there. it just keeps the oil level at the rocker arms. There should be another small copper line that goes to the piece in the middle of the rocker arms as well this is the supply line. I am not sure which line you are talking about. one of them (with the narrowed end) just goes into the hole and what ever oil doesn't runout at the rocker arms gets poured down this hole. the small copper line comes from the other side of the engine through the block and up to that middle piece and supplies the oil to the rocker arms. If that is the one that is broken you need to get a new one, rocker arms need a little bit of oil....

This is what it’s supposed to look like Spot:
http://www.pbase.com/dennygraham/image/114892256/original
The copper tube feeds the rockers and the steel tube simply drains the excess
back to the lifter gallery.

Denny Graham
Sandwich, IL

Denny,

Thanks for supplying an excellent picture for reference. The piece in question is seen in in your pic. Where it loops back over the rocker arms is where it was cut, in the middle of where that shiny piece is on yours. When it was cut both ends were crimmped off. I pulled out the left hand piece with the tapered end. The other piece(still connected) is crimmped off. My question was whether or not adequate oiling would occur with it this way. Logic told me that it must, as the previous owner obviously ran it this way. For how long I don't know.

Thanks for the comments.

In my short time here at the bolt i've seen At least 3 threads about people discovering the tube pinched AND the broken piece in the engine somewhere. I'm starting to put together a theory on this one, let me know if I'm crazy.

People believe that pinching the return tube off in both the 235 and 216 increases the pressure to the rocker shaft and thus oils it better. The easiest, and laziest, way to do this is to take a pair of needle nose pliers to the tube and crimp it flat. They rarely cut it off since that could create metal shavings that could get into the engine. The pinched off but still hanging-on tube has a flat part and flat sections (think engineering section, like a beam) are weak in bending. Also, the pliers put a bunch of nicks into the steel which are actually stress risers. So now the owner goes and does tens of thousands of miles in his vehicle and the now relatively floppy tube with stress risers vibrates until the metal fatigues and the part falls off, hopefully not doing any damage in the process.

I found the end of my tube in my 235 at the back of the head up against the valve spring with valve spring marks worn into it.

That's my theory, even though it didn't answer your question.

Anyway, it should run fine with the tube pinched off.

Back in the days of non detergent oil or oil with very little detergent, it was common for small oil passages to clog up. Chev, as well as Y-blocks were notorious for the rockers not getting enough oil and they would quite often get so dry that they would squeak. The common fix for a Y-block was to run an extra oil line to the rockers and the common fix for Chev was to pinch the overflow line in hopes of keeping enough oil flowing through the rocker shaft to prevent clogging of the oiler holes in the shaft. For the most part, both methods worked in their day.

First of all, Brokenhead, the actual supply line is present and intact.

Ringleader, your theory is a good one. I love the way you think and answered the questions I had about how and why this occured. Crenwelge, you were dead on too!! I never thought that the PO (or his mechanic) simply pinched off the tube and then over time the tube broke on it's own due to being weaker at the crimp. That explains why the piece with the tapered end was still in the hole in the head.....the guy only CRIMMPED IT. He didn't actually CUT IT!!! He would have removed that little end piece if he had.

You guys are the best at figuring out mysteries like this one. It was fun to learn and I appreciate you chiming in and sharing your insight. That's what I love about this site.

Thanks so much!!!