The Stovebolt Site Forums The Shop Area Engine Shop No oil to Rocker assembly.

'59 235, when adjusting the valves we noticed no oil was flowing through feed tude and rocker shaft. Removed rocker assembly and cleaned everything, no blockage at all. Pulled out flow tube and the plug located on the side(head) near the feed tube. Sprayed it clean with brake kleen again no blockage!!!

We were thinking is the head bolt between the feed tube and the plug where the oil supply comes from and can it be blocked or not drilled (no passage)?
Or should we run/plumb an oiling system via the oil filter assembly?

I would like to fix this correctly but I have no clue whats beyond that plug? Oil pump? Blockage?

Any ideas I'd love to drive this thing!!

thank you
JM

Hey JM

remove distributor, insert long round stock with a flat end and hook up electric drill. spin oil pump and see if oil will come to gallery. It will take a while till all lines are filled. If you have the oil pressure gage hooked up check the pressure.
What did you do to the engine? did you had the oil pump our.
Did you had the distributor out? If so you might have not engaged the oilpump with the distributor shaft. If you are a touch to high with the distributor the shaft will not slide into the pump gear.

good luck

Thanks Fritz
I actually just bought it, "just rebuilt".

I will play with the distributor and see if it is properly engaged.

Where do you measure oil pressure at on this lug? The one in the cab reads 1/2to3/4 up on the scale.

thx again,
JasonM

my 53 has a proper gage. Go get a pressure gage in
adapted and hook it into the block where the pressure sensor is mounted. Either put a TEE fitting in or remobve the sensor.

good luck

There has been plenty of talk about no oil to the rockers and about a mysterious special head bolt,someone has mentioned there is two different head gaskets for the 235. One is for the 54 on back and the other is for the 55-62,the differences is the hole for the oil passage and if I can remember correctly if the earlier gasket is put on the later motor it blocks the oil going to the rockers. If thats the case thats what I had done to the 57 235 I rebuilt for my 37,it got no oil to the rockers and what I did to get oil there was to take a cut off wheel and grind a groove about a 1/8 of a inch wide and about 1/8 deep through the threads on the head bolt and now it gets oil. It might seem crude to do it thay way but it works and I dont it 4 years ago and no trouble since. Jeff

If at some time in the past a earlier top end was installed the mechanic could have installed a plug in the block oil port and used a special drilled head bolt as per chev parts book instructions. Here is what the parts book says.

Drilled 235-261 Head bolt:

From 1938-62, only two head bolt part numbers are listed for 216, 235 and 261. Long and short except for a special drilled bolt, used when a 59-62 block is used with earlier top end* to reduce the oil flow to the rockers.

Note: Use with drilled bolt
Plug # 37 64 579
Install in block oil port near right center head bolt.
(This plug blocks the original oil path and sends it through the drilled head bolt)

* The cylinder head did not change but the rockers did.

A question my friend and I have about checking to see if I have the correct "drilled" head bolt.

Can we remove "that" head bolt, (inspect for type, and possibly grind the groove) as recommended by Jeff without ruining the head gasket?

How long is this bolt and how long should the 1/8"w X 1/8"d cut be along the threads?

Thank you,
Jason

I has also been reading some archives and there is talk about having to ristrict "TOO MUCH" flow to the top end.
Will cutting the bolt too deep/ long create too much flow to the top end if this is in fact the issue?
Thanks,
Jason

The factory bolt had a 1/16" hole up the center part way, to a hole out the side above threads. the 1/16" hole was to restrict the flow. I would reccomend making one yourself, rather then gringing the threads.

There is no problem removing one bolt and reinstalling it.

You're the man Dave!!
We will see, I have the truck at a good friend of mines. He will be cheking the head bolt for me and then we'll go from there!!

Thanks to all
jj

I don't know about you but I wouldn't be drilling any holes in the bottom of that hole....
scary.

If your engine needs this special drilled bolt for the oil to get up to the rocker assembly and it was just rebuilt, chances are that the drilled bolt got installed in a different location on the head. I would remove all the long head bolts one at a time to see if it has been installed in a different location. Just retorque them to 90-95 ft-lbs (with oil) as you go. There is no problem doing this, since you are supposed to do this after you run the engine for the first time after a rebuild along with adjusting the valve lash. I have a 261 block with a 235 head and I was just looking in the hole where this drilled head bolt would be installed next to the oil tube (by the way I do not have a drilled head bolt. I looked for this special bolt the last time this drilled head-bolt topic came up on this forum.) from what I saw there is hole approximately 1/2" below the head surface inside the bolt hole perpendicular to lifter side of block. The oil tube hole comes up on the other side the same head bolt hole, so it looks like the oil flows around the unthreaded portion of the head bolt to get to the rocker oil tube. With the side cover removed on my 261 you can see a raised channel in the casting where the oil flows up through the block and into the head. It would seem to me if you had to drill a head bolt to get oil to the rockers that you would not have this raised oil channel, since apparently the oil channel is directly below the drilled head bolt. This drilled head bolt system seems like a bandaid fix to an engineering error if you asked me.

cujo8, it is not a " engeneering mistake". It is only used on 1959-62 engines that are using earlier rockers. The only reason Chev sold the special bolt and plug, was for installing a new short block and using your early top end.

Okay guys, I found the special bolt! Last one we checked but it is now flowing oil as it should, I hope!
If this bolt is used on an older rocker assembly setup, which do I have?
[img]http://photo.starblvd.net/MunsonMotorsports/6-5-1.jpg[/img]
As you can see a couple of these are at their adjustment limit.
I would preffer to setup the rocker lash properly before ruining seals, and the hyd and solid adjustment proceedures Ive seen are different.
They have been adjusted snug to quiet them, since 2 of the were .25" of gap, but Im worried they're maybe too tight... I have some new rocker bolts on the way.
Thank you for the expert advice that really helped me save this ol' girl.
J

It looks like the round ball on the adjuster just back from the center connector tube is completly worn away. I'm sure more are that way. This is from lack of oil.

The only way to tell for sure if you have early (1953-58) or late(1959-62) rockers is to pull one off and look inside and see if the groove inside is centered (early) or offset 1/4"(late).It is easy to pull the end one just by backing of the adjuster.

If you want it set up right, now that your using the drilled head bolt, you should use a connector setup that has the loop tube that dumps on head. What you have now will force more oil to rockers, which could cause oil consumption.

So the brass looking "inner liner" of the rocker that rides on the shaft will determine if it has solid or hyd lifters?

I just had it apart but cant remember if they were centered or 1/4" offset!

I have new adjusters on their way!

Dave you're from Wash, thats where my truck came from...

Seen her before?
[img]http://photo.starblvd.net/MunsonMotorsports/6-4-4.jpg[/img]

Thx again,
Jason

Jason, The groove does not tell anything about the lifters, only how the oiling setup should be.

The way I would check to see if it has hydraulic lifters is to turn down the adjuster on any valve that is closed a few turns and let it sit for a hour. Then measure how far that push rod is sticking out of the head. Then back the adjuster off and see if the push rod comes up out of the head any. If it is a hyd it will come up, if solid it will stay the same.

I'm searching for clarification. I have a 1960 235 with the 848 heads. There was a terrible mess under the valve cover (rat's nest) and so I've started a cleaning operation. When in there I found that no oil was getting to the top of the head. I pulled the rockers and rocker shaft to expose more area to clean and noticed a head bolt to be sticking out and not flush with the surface and I have no idea why. Could it be the infamous drilled head bolt and if so would it be sticking up like that as an adjustment to the oil flowing through it? Also, the oil tube that supplies oil to the rocker shaft seems to have a crimped end on it and I'm not sure if that is stock or if someone before me altered it.
I have posted pictures here:
http://s281.photobucket.com/albums/kk214/PirateYarr/1957%20Chevrolet%203104/Rockers/
Can I remove that oil tube so I can get a socket on the head bolt to tighten it down? How would I remove it?
Thanks,
Nick

Along the same lines at nickcs2004's question, do the rockers get lubed by the tube or the drilled bolt or both? Or does the drilled bolt somehow feed the tube?

I answered my previous questions except for why the copper oil tube line is crimped on one end.
I have also located the drilled head bolt. It is the one with a grove across the top. It can be seen in the following pictures:
http://i281.photobucket.com/albums/kk214/PirateYarr/1957%20Chevrolet%203104/Rockers/DSC00375.jpg
http://i281.photobucket.com/albums/kk214/PirateYarr/1957%20Chevrolet%203104/Rockers/DSC00378.jpg
Also, It's location, now knowing what it looks like, can be seen in the rocker assembly pictures linked in my earlier post.
It was very corroded and the hole in it was completely clogged. I cleaned the hole but I'm not sure how to clean the part it mates to at the bottom of the bolt hole. Theorizing, if the bolt hole was clogged so is this other oil passage at the bottom of the bolt hole. Any suggestions on how to clean this to get the oil flowing once again?

Bump

take the distributor out and use a long screwdriver with the handle cut off to spin the oil pump with a drill motor, the pressure should clean it out.