235 oil passage qeustion

[Rickcopeland11]

hey guys, i have a '55 3100 1st series with a 235 straight 6 and i am unsure about how it is supposed to oil. i know for sure where the oil pump sends the pressurized oil out of the block and i think i know where the oil returns to the block.... my assumptions jive with the full pressure oiler article by bruce childs from this forum http://www.stovebolt.com/techtips/full_pressure.htm my existing connections are very close to his home made connections. my worry is about oil getting to the head, we totally rebuilt the motor and we do not see oil making it to the head when we turn the oil pump with a screw driver drill. I have noticed that the rocker arms have an internal oil journal and a little hole on the top i assume that for spraying oil everywhere else inside the valve cover... are the rocker arm assemble bolts supposed to be the type with an oil passage up the center? how does oil reach the head? thanks for all the help guys!

Rick

[Fred T]

I'm attaching a drawing of the oiling system on the 235.

Oil for the rockers comes off a cam bearing. In the lifter cover, there is an 1/8" tube that goes from the oil passage in the lower rear, and goes to the center of the block, where the oil passage that flows up to the head. It's been a while since I had the head off one, but I believe the passage goes into the headgasket, where there is an opening in the headgasket and the oil flows around the head bolt and up. Near the top of the head, this passage goes straight in, then up to the tube for the rocker lube.

Yes, you need oil here. The top of the tube, where it passes through the fitting, is open on the inside, putting oil inside the rocker shaft. In the rocker shaft there is a hole in the bottom inside each rocker arm, lubricating the arms and dripping on the valve stems. Where the tube turns down and ends is an overflow of sorts. The end is squashed down to slow the flow. From there the oil returns to the pan via drain holes in the head.

Problems I have found on these engines with the rocker oilers.

1. Tube inside the lifter cover is easily plugged. It's easy to remove. You can also spin your pump with this tube off to be sure oil is getting pumped through the cam bearing.

2. Improper headgasket installation. If the headgasket is upside down, the passage is blocked.

3. Sealant on head bolt. Some think that since the V-8 needs sealant on the head bolt threads that it should be used on the six. This head bolt can not be sealed, if there is too much sealant used it plugs the oil passage around the shank of the bolt.

4. Upper tube slippage. (this one took a while to figure out) On my current 235 the solder that holds the tube in the fitting failed. When I installed the rocker assembly, the tube got pushed down and blocked the oil passage inside the head. Repaired by repositioning the tube and silver soldering in place.

For such a simple engine, the rocker oiler on the 216/235 is complex, and has several places that can fail. If you oiled things when you assembled, the engine can be run without oil to the rockers. But if the oil isn't flowing to the rod and camshaft bearings the bottom end will fuffer.