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-   -   Project M54 Engine: Head (http://forum.e46fanatics.com/showthread.php?t=912095)

jjrichar 03-27-2012 12:21 PM

Project M54 Engine: Head
15 Attachment(s)

Link to other parts of the project

Once the camshafts have been removed, pulling off the head is a pretty simple process. The head can be removed with the camshafts still attached, but unless you weren't planning to remove the camshafts at all, I would remove them first, and then pull off the head. The head with everything off it is not that heavy (21kg). Putting it on and off can easily be done with one person using a little care. If the camshafts are fitted, the extra weight makes it all a bit difficult (33kg).

My Bentley manual calls for a special E12 torx socket BMW tool to remove the head bolts. I don't know why this is. I have a standard Kincrome set of torx sockets. The E12 one with an extension bar worked with no issues getting in there. With the camshafts removed there is loads of room. With the camshafts fitted, it's pretty tight, but these tools still worked.


While there was plenty of torque on the bolts, it was less than I expected. I only had a breaker bar that was about a foot long, and to be honest I was surprised to find that this was enough. Something a bit longer would have made it a breeze. For installation I would use something quite long so it is easy to get the correct angle of rotation after initial torquing.

There are 16 bolts in total. The 14 main M10 bolts, plus another two smaller bolts that go into the timing chain cover at the front. When removing the main M10 bolts, my Bentley manual calls for a progressive loosening of the outside bolts first moving into the center bolts last.


When the head bolts are removed, pulling off the head is quite simple. The head gasket is metal, so nothing is stuck, and everything just pulls apart nicely.

This is what the bottom of the head looks like after removal.



And the top of the block



Installation of the head is something that needs to be done properly, otherwise you will have problems later.
You will need:
- New head bolts
- New head gasket
-Cleaned up the head and block perfectly with no remains of the previous gasket

Please excuse the state of the block and head in these photos, also I'm not using a new gasket or bolts. I just wanted to practice a few times to see how it all went, and take a few photos.

One of the difficulties is placing the head onto the block so it goes straight on, and not damage or scratch anything. I used two 10mm wooden dowels that fit into the bolt holes where the head alignment dowels are fitted. Also the timing chain gets in way. If you have a second person, they can feed it through. If not, it is a simple process of stacking the chain up after you have pulled the chain guides together. Don't worry about the chain falling down. I actually tried to push it down there. It won't fit. Also, there is a lip on the inside of the timing chain cover that sits under the crankshaft sprocket that stops the chain falling off the sprocket. It's designed so that when you remove the upper timing sprockets, there is no way the chain will come off the lower sprocket, and the chain can't fall down the hole. When I removed all of the timing mechanism weeks ago, I always had the chain tied to something to stop it from falling down. I know now that this is not required.



Once the head is on, the bolts need to fitted and tightened. When putting in the bolts, make sure you give the threads and the washer a good squirt of oil so they torque correctly.

The torquing sequence is below. The Bentley manual calls for initially 40Nm. After this, go over each bolt in the sequence and turn 90 degrees. Now repeat the whole sequence again with a further 90 degrees of turn. At the end, each bolt will have 40 Nm + 90 deg + 90 deg.

When I initially put on 40Nm in the sequence, I went back to the center bolts and found they needed a bit of a tweak to get them to 40Nm again. Make sure you go over each bolt in sequence again and ensure they all have 40Nm applied.


To turn each bolt through 90 degrees, this is what I used. I made it up on my computer, then printed and laminated it. You could just as easily hand write this on some cardboard using a protractor. The bottom circular piece that has the angles marked is loose on the extension bar and doesn't turn. The arrow is snugly fit on the bar, and turns as you tighten the bolt. On the head I found it easiest to stick the circular piece to the head with some blu tac. You can do this because the top of the head is flat. On other components that aren't flat, you could use a wire that is bolted to the block, and the other end holds onto the circular piece.

The way to do this is to go give each bolt 90 degrees of turn in the correct sequence, then go back again and repeat. This will require a fair bit of force. I used a breaker bar that was1m long, and found that I only needed to hold it about 60cm along to make an easy job of it.



Doing all of this is quite easy, as long as you take your time and are methodical in the sequence you tighten the bolts. The biggest issue is getting lost in your tightening sequence, and either not torquing one bolt, or doing it twice. When having a bit of a practice, I was very quickly asking myself "which one did I just tighten". My best advice is to place something next to each bolt before you start, and then remove it when you are done with that bolt. The problem is that if you get mixed up you will have to loosen everything off and start from scratch. This means a new gasket, new bolts, and lots of tears. BAD.


Moral of the story. Take your time. Come up with a plan so the sequence of tightening is done correctly.

With the head off, it needs to be tested for flatness. If not flat it will need to be machined flat prior to installation. The maximum it is allowed to be machined is 0.3mm. Then a head gasket that is 0.3mm thicker would be used.

Here is how you test for flatness. The specs from the BMW TIS are a maximum of 0.05mm deviation. In other words, when you put on the straight edge, you shouldn't be able to get a 0.05mm feeler gauge in there anywhere.

The block needs to be tested in the same manner.



Also inside the head is an oil non return valve. There are two oil feed lines that go to the head. One goes to the camshafts, the other goes to the chain tensioners. Only the line that goes to the camshafts has a non return valve.


ddaniel1 03-28-2012 12:20 AM

JJ, thanks, love these.

latitude39 03-30-2012 03:53 PM

Ring ridge??

Was there a ring-ridge, which would be on the cylinder walls at the limit of travel of the top compression ring?

How does that part of the cylinder feel to your finger tip? How many miles on the engine?

jjrichar 03-31-2012 12:54 PM

Yes, there does feel like there is a bit of a ring ridge, but this could be due to build up of residue in the part of the cylinder wall rather than wear, as the cylinder, to my untrained eye looks to have very little wear at all. I'll soon have access to the type of micrometer that you would measure all the specs on the various engine components. This will give me a better indication of how much wear has occurred.

At the moment the engine is completely pulled completely to individual pieces. Crankshaft out etc. I took one of the compression rings and put in down into the bore of its cylinder to see the gap at the ring join. It was about 0.5 mm. This surprised me how much this was. Either the cylinder wall or the rings have had significant wear. Hopefully it's just the rings.

As far as the engine life is concerned, I have no idea. I found the engine is the world's filthiest shed that had about a hundred different BMW and Mercedes engines scattered amongst an equal number of every other bit of the same cars. Suspension components and drive trains were stacked up to the ceiling. The men who worked there spoke no english, and therefore I had no idea of the engine's age. I suspect it's an early 00's engine. Some of the date stamps on the components are late 2000.

Where I live is a little easy going with the way they fix cars. Across the road from the place I bought this engine, was another BMW parts place. They had half a 7 series body there for sale. Obviously it had been in an accident. They got an angle grinder, cut it in half, and were selling the good half. Find another half, get it welded together, and hey presto, new 7 series body. As you might guess, there are a lot of bent cars driving around here.

In a nutshell, they would have no idea of the engine's history.

Stinger9 04-01-2012 10:58 PM

You're doing amazing stuff here for all by posting these extra good pics. Fascinating!

Will look forward to following whatever else you post.


jjrichar 04-29-2012 11:55 AM

Some additions to the above post for those who are interested.

kraimer 06-13-2012 07:18 PM

You should compile this into a book and sell these! This is some valuable information!

Mango 06-14-2012 03:27 PM

awesome! does this engine have known consumption issues? did you check the roundness of the cylinder bores? i know some m54b30s burn oil and i think the cylinder bores are known to be ovaled out on some m54b30s. saw on bimmerforums.

jjrichar 06-15-2012 02:09 AM

Regards the engine's history and possible consumption issues, I don't know. I bought it from a place that sells second hand engines, and they had no clue to its history.

Regards bore ovalness, there is some stuff regarding this on the post on "pistons and conrods".

Thanks for the feedback. It's nice to know that people are getting something from this.

Barneyhyphen 10-07-2012 09:48 PM

6 Attachment(s)
My attempt at the cam timing jig....

Laminated three pieces of 3/4" MDF together for the body of the jig. Used M8 x 1.25mm x 50mm bolts with nut/washer assembly JB welded in each hole and a locking nut on the back side to lock down each one.

Thanks all the guidance.


jjrichar 10-07-2012 10:57 PM

I'm really interested to know how it all goes when you do the timing. Keep us updated.

Barneyhyphen 10-10-2012 08:21 PM

Will do. Timing's all done and inlet manifold going back on tomorrow.

Thanks again for all your DIY "project" posts. They've made a tedious job far more manageable.


LeMansteve 10-12-2012 08:27 AM


Barneyhyphen 10-14-2012 08:21 PM

All done and back together. NO CEL! car feels real peppy. Fairly zippy little boat anchor.

For those who may care....I didn't bother making a jig for the back of the head (to hold the cams in the right position), expended too much energy on the front jig! Instead, I set them up and placed a 12" steel ruler, edge on, across the tops of the two cams, (between the two top sides of the square ends of each cam), adjusted to ensure that the entire flat of each square end was in FULL contact with the edge of the ruler then kept a hairy eyeball on the whole setup, to make sure they remained stationary and as set up.

I'm sure there'll be some chastising on the way but it seems to have worked remarkable well for me.


jjrichar 10-14-2012 11:09 PM

You've made my day. Not having an engine in a car here to test this, I didn't know if the tools were going to work. Very happy that they do.

Just a note for others who are going to do this. The rear jig is designed to keep the vertical sides vertical, not the top side horizontal. The vertical sides are machined accurately, whereas the horizontal sides are just the remains of the camshaft casting, and not accurately formed. In this case it has worked, as there is obviously a reasonable amount of fat in the setup that would allow for small inaccuracies. I would however recommend that people make the rear jig to reduce the risk of incorrect setup.

PancakeBimmer 05-21-2017 10:25 PM

Sorry about the bump. Does anyone know what the small holes on the exhaust between cylinders sides are? Coolant or oil?
I sure hope it is coolant.

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