Head bolt question (pg. 3)

[turbodan]

I browsed through the thread and I didn't see why you're removing the crank nut. You don't need to do that to R&R the head.

If the head is visibly cracked its garbage. Used heads are in the 150-250 dollar range. Don't spend any more than that. Resurfacing should be all thats necessary if the head is good and shouldn't cost more than about $45.

[VW+bimmer=bliss]

I browsed through the thread and I didn't see why you're removing the crank nut. You don't need to do that to R&R the head.

If the head is visibly cracked its garbage. Used heads are in the 150-250 dollar range. Don't spend any more than that. Resurfacing should be all thats necessary if the head is good and shouldn't cost more than about $45.

It had a broken timing chain guide, and the front crank seal was leaking, so the hub needs to come off. So you are saying if it has cracks, they can not be repaired? Maybe I saw some casting irregularities with carbon in them. I had them check for cracks and what not.

[VW+bimmer=bliss]

Sorry to hear. That really sucks.

The hub with the v-belt on it? Are you talking about the vibration dampener? Once you have the front pulley off then you can just pry the dampener off the hub. Here the dampener has been removed and I'm pulling the hub off the crank.

wow, I AM A SPACE CADET.

[demetk]

Sorry to hear. That really sucks.

The hub with the v-belt on it? Are you talking about the vibration dampener? Once you have the front pulley off then you can just pry the dampener off the hub. Here the dampener has been removed and I'm pulling the hub off the crank.

wow, I AM A SPACE CADET.

LOL. Wish I was an actual space cadet. That would be fun.

[turbodan]

Repairing a cracked head is possible with welding and machining but I don't think its an option for some types of cracks. Its also very costly. Good used heads are cheap and common.

[VW+bimmer=bliss]

Machine shop could not find any cracks in the head, anywhere! And the head gasket was just fine also, what gives? Maybe a smaller failure in the gasket i could not see?

[Frybrid 524td]

How was the head tested? A visual inspection after hot-tanking isn't proof of no cracks.

[VW+bimmer=bliss]

How was the head tested? A visual inspection after hot-tanking isn't proof of no cracks.

They showed me, it was some kind of aluminum frame and it had a cylinder on it that would clamp to the head, each individual cylinder, and they would put water in there and pressurize it. No leaks any where, and no pressure drop when the air supply was removed....so who knows, maybe the gasket let go.

[VW+bimmer=bliss]

And they drove the rear intake rocker shaft to far in the head, now i can not put my head on the block cause i can not put the the flippin head bolts through.
Fuck.

[demetk]

And they drove the rear intake rocker shaft to far in the head, now i can not put my head on the block cause i can not put the the flippin head bolts through.
Fuck.

Pics please.

[Mike W.]

And they drove the rear intake rocker shaft to far in the head, now i can not put my head on the block cause i can not put the the flippin head bolts through.
Fuck.

Sometimes you have to bang them with a hammer to move them a MM, other times the rocker springs will push them out of place. Push the spring out of the way, grab a channellocks and you should be able to work it back. Twist and push. No biggie.

[VW+bimmer=bliss]

And they drove the rear intake rocker shaft to far in the head, now i can not put my head on the block cause i can not put the the flippin head bolts through.
Fuck.

Sometimes you have to bang them with a hammer to move them a MM, other times the rocker springs will push them out of place. Push the spring out of the way, grab a channellocks and you should be able to work it back. Twist and push. No biggie.

I did just that, worked great! Until I noticed also about half of the eccentrics were not facing the right way. So i took the head off the block again, and went to rotate the cam to relieve sping pressure on some of the valves and BINGO the intake rear rocker shaft to slides all the way to the back of the head taking intake rockers #4,5,6 with it! I am just a little ticked now. Sorry no pics, phone was dropped into a bucket of PB gasoline and coolant.

[Mike W.]

And they drove the rear intake rocker shaft to far in the head, now i can not put my head on the block cause i can not put the the flippin head bolts through.
Fuck.

Sometimes you have to bang them with a hammer to move them a MM, other times the rocker springs will push them out of place. Push the spring out of the way, grab a channellocks and you should be able to work it back. Twist and push. No biggie.

I did just that, worked great! Until I noticed also about half of the eccentrics were not facing the right way. So i took the head off the block again, and went to rotate the cam to relieve sping pressure on some of the valves and BINGO the intake rear rocker shaft to slides all the way to the back of the head taking intake rockers #4,5,6 with it! I am just a little ticked now. Sorry no pics, phone was dropped into a bucket of PB gasoline and coolant.

Ugg. Sorry about the phone, but that may be the most toxic soup I've heard of one being dropped into. No, come to think of it one of my crew dropped one into a sewage pit and recovered it, if you want to phrase it that way, several years later. No attempt to find out if it still worked was made. At any rate, sometimes I find it necessary to line up the rocker shafts and put a bolt in, a shorter 12MM bolt, not a head bolt, in each one to keep them in place. Rockers I leave loose, then adjust after the head is torqued down.

[VW+bimmer=bliss]

I know right? The R button on my keyboard is quite stubborn now and the camera and LED refuses to work, but everything else works just fine! I was amazed, it smells as though my phone needs a headgasket now
So what you are saying is the rocker shafts will stay in place once you get the head torqued down? Because the other 4 are quite snug in their bores, the intake rear on the other hand, in can push it freely with my hand and if I remove the circlips, can easily remove it from the back of the head. Next to no resistance in the bore is felt. In the Bently is says they have to be driven out with a hammer and mandrel or the special BMW tool, so that makes me think the machine shop messed something up.
Also the bently just states to install the shafts into their original position, taking note of orientation and intake, , exhaust sides, etc, nothing about what to do if the shaft does not stay in the head.

[Mark 88/M5 Houston]

I know right? The R button on my keyboard is quite stubborn now and the camera and LED refuses to work, but everything else works just fine! I was amazed, it smells as though my phone needs a headgasket now
So what you are saying is the rocker shafts will stay in place once you get the head torqued down? Because the other 4 are quite snug in their bores, the intake rear on the other hand, in can push it freely with my hand and if I remove the circlips, can easily remove it from the back of the head. Next to no resistance in the bore is felt. In the Bently is says they have to be driven out with a hammer and mandrel or the special BMW tool, so that makes me think the machine shop messed something up.
Also the bently just states to install the shafts into their original position, taking note of orientation and intake, , exhaust sides, etc, nothing about what to do if the shaft does not stay in the head.

The rocker shafts are notched for clearance at the head bolt locations; that is why it is important that they go in the correct position. As soon as a head bolt is dropped in place the rocker shaft will not move more than a millimeter or so back and forth.

[VW+bimmer=bliss]

I know right? The R button on my keyboard is quite stubborn now and the camera and LED refuses to work, but everything else works just fine! I was amazed, it smells as though my phone needs a headgasket now
So what you are saying is the rocker shafts will stay in place once you get the head torqued down? Because the other 4 are quite snug in their bores, the intake rear on the other hand, in can push it freely with my hand and if I remove the circlips, can easily remove it from the back of the head. Next to no resistance in the bore is felt. In the Bently is says they have to be driven out with a hammer and mandrel or the special BMW tool, so that makes me think the machine shop messed something up.
Also the bently just states to install the shafts into their original position, taking note of orientation and intake, , exhaust sides, etc, nothing about what to do if the shaft does not stay in the head.

The rocker shafts are notched for clearance at the head bolt locations; that is why it is important that they go in the correct position. As soon as a head bolt is dropped in place the rocker shaft will not move more than a millimeter or so back and forth.

I did put the head bolts in, and it still moves...I have all new head bolts as well, thought they might be the wrong ones so for shits and giggles i put the old ones back, to no avail, the shaft still slides freely to the back of thehead. Now I am in a predicament because my engine block is at TDC and the cylinder head is not, and I can not rotate the cam to the correct position because three rocker rams are not on their perspective lobes.

[VW+bimmer=bliss]

II put the three rearmost headbolts into the head on the intake side and the rocker shaft moves alot more than 1MM, more like 5MM. All three other shafts (IF, EF and ER) wont even budge and are in their ccorrect positions. Damnit I wash I could post a video on youtube but I have no ccomp. And my phone is on its last legs

[Mike W.]

Do you have the threads run all the way down? I don't remember how long the shoulder on the head bolt is, but it's not real long and may require more than just sitting in there, but like Mark said, when installed the shafts will only move a MM or so. Let me know if pictures will help, I should be able to mock some up with parts.

[turbodan]

As a general rule you should avoid hammering on anything inside the cylinder head. Rocker shafts especially. Hammering means something is binding or otherwise in the way, and though you will probably get it apart this way it is very likely to damage the head casting or rocker arms in doing so.

If you can determine the source of the binding you can determine if its okay to apply force. Deposits on the shafts can cause problems.

[Mike W.]

Often rocker shafts on M30s require a considerable amount of force to move them. Regardless...

Here is a pic. Note the short shoulder and the notch it goes into which is already recessed some into the head.

[demetk]

Often rocker shafts on M30s require a considerable amount of force to move them. Regardless...

Here is a pic. Note the short shoulder and the notch it goes into which is already recessed some into the head.

Wow, I had no clue what you guys were talking about, until I went and had a look-see on one of my heads. Now I understand. So will the shafts align themselves with the bolt holes when the bolts go in or do they need to be tapped into alignment before you install the bolts?

[Mike W.]

No, it's gotta be close. If it's close enough it'll self align, but it's got to be pretty close. But you can work it by feel and go from there.

[VW+bimmer=bliss]

Wow, I messed up
when I had unwrapped the cylinder head, I almost immediate ly put it on the block. When I had about half of the bolts in, I noticed ALL of the eccentrics were not facing the right way. No bolts were torqued down, just barely finger tight. So I took the head off, and proceeded to turn the cam so I could relieve spring pressure on some valves. I stopped when I noticed the rear cover gasket had been damaged by the machine shop, no biggie wish they had told me, but I had a spare, removed the cover and proceeded to turn the cam ( NO head bolts are in at this time) maybe 180the degrees of rotation later the rockker springs forced the intake rear shaft out of the head. Keep in mind this was after i had lightly tapped the intake front rocker shaft to move the rear one so I could put the head bolts through. I put the head back on the block and held the rear intake rocker shaft with my finger and put the headbolts in, still, the rockers sat over the edge of the cam lobes on cylinders #4,5 and 6. I am very confused as the other ocker shafts did not budge at all with no bolts in their respective holes. I took it back to the machine shop, and they said they can make a spacer to fit on the end of the rocker shaft plug underneath the rear cover. Could this be detrimental to oil flow in the rear part of the head? It is just to hold the rocker shaft in place so the rockers them selves will be held in the middle of the cam lobes and so I can also put the head bolts in as well, thoughts? I am very frustrated as to why only this shaft is not staying where the others stay just fine.

[VW+bimmer=bliss]

So thoughts on the spacer to hold the shaft in place? I thought it would be fine since oil neither enters or exits from that point of the rocker shaft. This is under the rear cover with the duck looking gasket.
Jon

[Mike W.]

I can't think of why it would be a problem, but why do it when all you have to do is wiggle and push the shaft while you run a bolt down. You don't have to torque it, just run a head bolt down and it should locate it.

And it doesn't strike me as odd that 3 stay in position and one moves, it's kind of random as long as the head isn't warped much.

[VW+bimmer=bliss]

Damn, did not realize how big that picture was haha.
even with the head bolts in, the shaft was no where near where it was supposed to be, the rockers sat almost 3MM over the edge of the cam lobes. Awesome, Thank you Mike for letting me pester you for information!