The Stovebolt Site Forums The Shop Area Engine Shop oil clog to rocker arms

Apparently I'm not getting very much oil up to the rocker arms on the used 235 I installed in my 50 Chevy pick up. A lot of sludge in the engine. Any ideas as to how I might be able to remedy this problem. Any help would be greatly appreciated.

What year is the 235?
What do you mean by not very much? 235's do not sent all that much to the rockers originally, especially at an idle.

Dave I believe it`s a `62 and hardly any oil. I read somewhere that there`s a bolt in the head that's supposed to bring oil up. Does that sound right or is there a clog that I can clean out?

A drilled head bolt is not used originally, it is only used when putting a 1958 or earlier rockers on a 1959-62 engine to slow down the oil flow.
There can be a number of causes for low oil flow to the rockers.
There can be slug build up in the supply path, or the rockers them self can become worn enough to block the oil hole on the shaft.
I would start with disassembling the rockers and looking at the shafts and rockers for wear.

There is an 1/8inch plug that seals the hole where they drilled the block. Its behind the side oil cover about an inch down from the lip. If you find the galley cast into the block that goes up to the head you'll see it. You might want to take that off and poke some wire around to see if anything comes up. Its also possible that the plug might be in to far. A very small chance.

Without taking things apart there is no real way to get to that galley. But since there are two 90degree bends at that plug, if sludge is going to settle, that's where it will do it.

I saw an engine a couple years ago that had and oil feed line off the filter assembly going right into the feed port on the head.

Instead of oil going back into the pan, it went to the rocker arms. GM should've done that from the factory, in my opinion.

The conventional wisdom at the time was oil didn't need filtered, just changed at proper intervals.

There was no filtering unless you paid for it.

As usual great advice for all my fellow stovebolters. Looks like I'll be looking for that 1/8 inch plug and then maybe disassembling them and looking at the shafts and rockers for wear.
Thanks to all.

Here is a link that shows the oiling path to the rockers

Its the third photo down.

knuckle knocker: I have found it useful to turn the oil pump with a drill and a common screwdriver shaft. I just used an old screwdriver that had a bad handle and cut the handle off. Use the biggest one that will fit in to the pump. Turn the pump to see where you have flow and where you don't. I found a clog in the line from the cam galley to the head. But my 235 is older and that line comes off quite easy. When I took the bottom fitting off and turned the pump I had oil. So that made it easy to track the line to the head as my problem. A bit of cork from a pan gasket was what caused my issue. Lucky for me I had the valve cover off and could see that no oil was coming up to the rocker arms. No harm to the rockers and shaft so Lucky me. You can pull the rocker shaft off to confirm oil to there with out too much trouble. Just an idea that won't require running the engine until you have oil where you want it.

Here is what I did to clear out my oil supply line to the rocker arms on my 235. I pulled the rocker arm assembly to access the supply hole in the cylinder head. Then I used a piece of copper wire (14 gauge I believe) to snake the hole. Then I took a large syringe to suck out the supply tube. This didn't work at first. So I used some penetrating oil and sprayed it down the hole. Then the copper wire, syringe. Oil, wire, syringe. It took me a while(about an hour) but I was able to clear the line.

Have a 1955 235 chevy now that is making noise. Looked and the little tube leading from the head to the lifters is cracked and most of the oil is not getting to the lifters. Panning to weld the piece and replace it when I can buy some round tuits; got any?

Had a 1955 4 door 235 50 years ago and the oil passage clogged and stopped oiling the rockers. A guy at Smokeys (yes that was him)in Datona Fla put a line into the head on the outside of the engine that bypassed the clog. Didn't have to drill anything as I recall. Kind of unsightly but worked great and the lifters were relatively quiet after that. Allen