M20B28 no oil in head

[michael_rpt]

Hello guys,
I decided to join r3vlimited forum because I think this is the best place to ask questions and find answers.
I started rebuilding my m20b25 and found out it's a good idea to stroke it. New mahle pistons, 130 conrods, 2242898 crank etc.
Whole engine was mount into the car, We put a bit of oil to the head and to cylinders and after few minutes it occured there is no oil coming to the head..
We checked the preasure in block - 4,5 bar.
We took the head away and went to the workshop that repairs only heads. Mechanic told me that somebody mount rocker arm shafts in the wrong way.. Is that even possible?
Head is from sETA - 1705 885, new asymetric schrick cam, new erling arms.
Guy told me that oil holes in the shafts didn't exactly fit the oil holes in the head in 100%.
REALOEM tells me that both shafts have the same number so there is no left and right.. There is only one position to mount them, am I right?
We've checked the oil pump, turned it and the oil squitted up, so I believe oil pump is ok, I used to run on it year ago.
Did somebody have the same issue?

[digger]

There is a right way and wrong way so the oil holes in shaft line up with the holes in head.

[michael_rpt]

Ok, so there is one reason found.
What about drilling oil holes? I also found a thread that it's necessary to make lubrication system working properly. Is that right?
I'm already getting crazy because in my engine there are already 3 people involved and nobody knows what's the exact reason.

[It's Soda Not Pop]

post up pictures if you can. That way everyone can get a more picture of what might be going on.

[digger]

Yes some don’t have all drillings as all the camshaft journals are not present on eta cam. I don’t think this wouldn’t cause no oil at all though

[ForcedFirebird]

Very simple. The rocker shafts have a direction. Oil holes need to face down to the block, and the rocker retainers have to line up with the rockers.

So, before installing, set the rocker shaft in the cylinder head with the oil holes down and the notch facing together. You can rotate each rocker shaft parallel to the ground, on the same side,and you will have differing results.

My guess is the rocker shaft oil holes were facing "up". I've seen this in my shop (that we had to repair) where a customer brought the head to a local machine shop, and installed at home. The machine shop had put it together wrong, starving the top end.

[82eye]

i always thought they would only orient one way with the shaft lockers. i guess it's possible to install them 180 off.

[michael_rpt]

i always thought they would only orient one way with the shaft lockers. i guess it's possible to install them 180 off.

That's exactly what I was informed in the workshop. But guy's statement was that he's not sure would it cause total lack of oil.
I found similar thread on forum and guy drilled 3 holes in the SETA head what actually I'd like to avoid..
I will send some photos as soon as I come to my hometown where the engine is. Anyway thanks for the tips.

[ForcedFirebird]

Actually, you are correct. I'm putting a head together right now. The rocker retainer slots make it so they can't go in the wrong way and have the shaft retainer installed, the slots will be on the wrong side.

That being said, it reminded me a guy at the race track had a head rebuilt at the local machine shop - they forgot to put the retainer for the rocker shafts, so they spun, flipped all the retainers off and the valve-train ate itself for lunch.

The only time you need to drill anything is if you are using a 7 bearing cam in a 4 bearing head. The eta (200 casting) heads don't have the 2nd, 4th or 6th oil passages for the cam. I have drilled eta heads to use 7 bearing cams.

[ForcedFirebird]

Reread your first post. Check the front cam journal, it should have a slot in it. The oil only passes when the slot faces the oil holes. I discovered this many years ago when I was checking a used engine. Sitting on the stand, I turned the oil pump shaft with a hand still and it built up pressure, but dead-headed. I thought something was wrong until I rotated the engine a little and the oil shot out of the oil spray bar. Long shot, but we had a member a while back that bought a cam that had the hole for the cam gear in the wrong place - perhaps that feature was left out of your cam?

[michael_rpt]

Reread your first post. Check the front cam journal, it should have a slot in it. The oil only passes when the slot faces the oil holes. I discovered this many years ago when I was checking a used engine. Sitting on the stand, I turned the oil pump shaft with a hand still and it built up pressure, but dead-headed. I thought something was wrong until I rotated the engine a little and the oil shot out of the oil spray bar. Long shot, but we had a member a while back that bought a cam that had the hole for the cam gear in the wrong place - perhaps that feature was left out of your cam?

Ok, I made a simple drawing. This is what you mean?

[digger]

here you can see the first journal (near bottom of pic just above flange) where there is a partial groove, there is also a full groove on the middle journal.

the partial groove moves oil to sprayer bar and the full groove allows oil to moves from one rocker shaft to the next

As stated above it is possible to install shaft wrong but either the clips wont like up properly or retainer wont sit correct so this should be obvious unless you don't know how the retainer is supposed to sit.

The other thing that could be wrong is a dud shaft, they aren't what they used to be from a quality perspective.

i would disassemble and check things thoroughly.

[michael_rpt]

I got some pics from the process while the engine was beeing rebuilt. Whats dud shaft?

[ForcedFirebird]

Ok, I made a simple drawing. This is what you mean?

The hole you marked is just left over from the drilling process. If you remove the rocker shaft, that hole goes all the way down to the cam journal. An eta head (200 casting) is missing some of those holes. There are also holes on the bottom of the rocker shaft bosses.

Digger means a "dud" as in some of the later production Febi rocker shafts had questionable quality. I had to send a set back when the rocker retainer slots were a few MM's off so bad, the rocker pad was edged off the cam lobe.

Oil to the head starts at the center of the block, next to # 1 head bolt (center, exhaust side), travels up to the top of the head, and to the center of the exhaust rocker shaft. Next, it travels around that center cam journal (the one that has a 180° slot around it) to the center of the other rocker shaft. Oil then travels from the center of the shafts to the rocker holes, then at the ends of the shafts where the # 1 and # 7 cam journals are fed, the slots on the # 1 and # 7 cam journals then feed the oil spray bar. Might behoove your shop to blow some compressed air through the head and make sure there's no obstructions.

Often times at work, I will run the m20 with the valve cover off to diagnose things. Just have to plug the big breather hose, and it makes a bit of a mess. Know it's kinda late for that (and appears you hired a mechanic), but for future reference when others look for this info, it's a great way to check on things. When I was younger, we would adjust rockers on Chevy push rods while the engine was running lol. Tighten the rocker nut until you hear the chatter go away.

Just out of curiosity, the head was completely dry when running, was a little oil pooling at the bottom of the head cavity, or just not coming out of the spray bar? How did you go about diagnosing lack of oil up top?

[digger]

maybe its my eyes, but are the rockers offset from the cam lobe somewhat more than they should? i thought they ran closer to middle of lobe normally ? i'm not at home to check things. if so perhaps the holes in the shaft are offset a few mm and no longer line up