The Stovebolt Site Forums The Shop Area Engine Shop Strange oil line on 235

I just took delivery of my 'new' 52 Suburban. The engine is a 58-62 235 (3764476). There isn't a filter. But there is an external oil line from the drivers side lower block (t'ed with the oil pressure guage) around to the block on the passenger side. (Tapped in the top near the head.) I was wondering if anyone had seen this before, and whether it might be safe to tap in and add a filter to this line. Thanks!

Sounds like someone run an oil line to head to feed rocker arms. Why, I can't say. Normally oil is fed up through passage in block. Passage may be blocked, so they used an external line. Don't know that putting old filter on would be a good idea. Might not leave enough supply for rockers.
Normally oil filter would tap off of T in block go through filter and return to block. If you wanted to put on oil filter, you should probably find out reason for the line being run to head and fix that first.

How would I check the passage to see if its blocked? Where does it come out that I could assess it? Supposedly, this engine has only around 3000 miles. Thanks!

Some heads do have on the pass side a pipe plug that tee's off the internal engine oil passage that feeds the rocker arms. I agree you need to know why they are using this external feed, especially since the engine has 3000 miles on it. Take the valve cover off when the engine is warm and start up to see if you are getting oil to the rocker arms. The oil should come out of the little hole on top of each rocker arm. It might fling a little oil around, cover your fenders etc to protect. If you are getting oil you are ok. If not then they may not have the correct long head bolt in the center location. or plugged coming up thru the block. What is your oil pressure? The oil for the rockers comes up this passage around the head bolt, takes a right towards the drivers side and then comes up inside the center rocker arm support, then feeds inside each rocker arm shaft and up to each rocker arm. This head bolt is cut back slightly about 1/2 inch down from the bolt head, and is different from the others. It is not uncommon for the rebuilder to get this head bolt in the wrong location. And it is not uncommon for the rebuilder to not clean or take apart the rocker arm assembly. The oil pressure line for the oil filter and return line are always on the drivers side, and they are next to each other. You can tee off ot the pressure line or use the other tapped hole on the drivers side for the oil pressure guage, your call there. I think that is all. Good luck.
t

I have rebuilt a few 235/261 engines and never noticed any difference in the head bolts other than the bolt length.The oil passage is detoured away from the bolt near the top so it feeds into the passage the rocker oiling tube.Remove the head bolt next to the rocker oil feed and push a length of stiff wire in the hole till it bottoms out. Note if there is sludge on the wire .replace the bolt.Remove the distributer, after noting the rotor position. using a drill motor with an old screw driver shaft or something similar, rotate the pump clockwise. Oil should flow out of the rocker pipe feed hole after a minute of so. If not try spraying some carb cleaner down the hole to clean it.

all 3 of my 235s have had the center head bolt that oil feeds through removed they have been put on a grinder and a spiral groove cut in it so more oil will flow by it it seems to work great i get plenty of oil to the rockers .maybe this will help

Jimfred, take the side cover off, the rear one . You will see a small piece of tubing coming from the rear cam bearing and going to the feed for the rocker arm assembly. It is a cast part of the engine block, disconnect the tubing and check it to see if it is plugged up. Blow some compressed air through it and then do like Tony said, remove the dist and run the oil pump, you should have oil coming out of the rear cam bearing, then take and blow a little air in the connection at the top were the tube is connected, this should clear the oil passageway to the rocker arms. Those liitle oil lines get plugged and you don't get oil to the rockers. Just be carefull and don't blow the air at anything, the gunk in the tube will come flying out.

I didn't think they still used an oil feed line off rear bearing after '57 year.

That " wrap around " oil line was & is a common fix for getting direct feed oil to the rockers when the main bearings on the crank are worn enough to suck oil pressure out of the system & not allow enough oil to the rockers.

Jimfred,

I want to see pictures of your burb.

Well, the oil pressure is pegged at 30. So you've given me a few things to check. I'm hoping the extra line was there before the engine was rebuilt or just someone's idea of extra good oiling... Oh, and it does go into the top of the (848) head on the passenger side...

A burb picture...hmmm... I can email a bunch to you...

Jimfred I wasn't getting alot of oil to the rockers so I took the rocker assembly off cleaned everything and while I had the assembly off I took a 2oz syringe (big one) and drew oil up from the oil passage. It was realy hard and I wasn't able to Pull much oil up. Well long story short used the syringe like a plunger up and down and after awhile it was like I pop a cork and the oil flowed nice and free. I am guessing that your main supply is blocked and that is the reason for the external line.