How hard is it to remove and replace the head on an m50

[rob101]

Well I hear that replacing the head on a SOHC such as an m20 or m30 isn't that difficult because setting the timing can be fairly straight forward. Now I am thinking of perhaps reconditioning the head on my m50 at some stage. Is it a difficult job and do i need any special tools for setting up the timing.

I do have access to some extremely knowledgeable mechanics through my work as well as their tools so it shouldn't be too intimidating. I've always wanted to get into this stuff and now with the winter approaching here (read it will not be 40 degrees celsius during most of the day at work) might be a good time to do it.

I suppose the part that I am most unsure about is setting the timing for the DOHC after putting the head back on. What techniques are used for this?

[grave77]

do you have the Bentley.5er manual? it has everything in it. they explained everything about setting the timing and removal/installation..etc

Edit: it would take you around 1 - 2 days if you're alone and one whole day if you have a partner with the proper tools. that's if you will remove the whole head system and replace the valve seals.

[Dave M]

Prior to the M50, I had never had the head off of a DOHC engine. I thought it would be a bit tougher than it was. No worries, if you follow the bentley, you'll have no problem.

In terms of tools:

you can either buy a 'cheap' $40 cam alignment tool or just use a straight edge to line things up.

Bentleys mentions a secondary chain guide tool, but two safety pins work plenty fine ;)

In order to remove smaller head bolts from the timing cover area, you'll need to modify a torx socket (grind it down to fit into a deep hole).

Otherwise, nothing to special needed.

The trick (if there is one) is not the cam alignment per say, but setting up the bolts in the cam sprockets. There is quite a bit written on this subject and I know I have a post with plenty of pics out there which details this procedure.

In a nutshell, go for it, you'll enjoy it.

Dave M

[rob101]

Prior to the M50, I had never had the head off of a DOHC engine. I thought it would be a bit tougher than it was. No worries, if you follow the bentley, you'll have no problem.

In terms of tools:

you can either buy a 'cheap' $40 cam alignment tool or just use a straight edge to line things up.

Bentleys mentions a secondary chain guide tool, but two safety pins work plenty fine ;)

In order to remove smaller head bolts from the timing cover area, you'll need to modify a torx socket (grind it down to fit into a deep hole).

Otherwise, nothing to special needed.

The trick (if there is one) is not the cam alignment per say, but setting up the bolts in the cam sprockets. There is quite a bit written on this subject and I know I have a post with plenty of pics out there which details this procedure.

In a nutshell, go for it, you'll enjoy it.

Dave M
thanks, for the record i have a bentley, but things can turn out different than what the bentley says sometimes.

[92E34]

You'll need a cam alignment tool.

It wasn't too bad when I did mine. If I totaled up the total days of work, came to 8 days. And I didnt disconnect the header. Just Lock the Flywheel and the rest is a breeze. As for your cams, make sure that you have the 4 dots on the cams facing up and your at TDC. I made a cam alignment tool with a piece of 1/8 steel plate about 10 inches long and 6 inches high. The cam height is the same as the outer lip of the head. Most things are 10 or 11mm. Make sure you replace your head bolts. And If you can get the Victor Reinz gasket set.

[Anton CH.]

You can always do it the "ghetto" way by using a ruler - worked for me. Set the bottom to TDC using the mark on the wheel on the front of the engine. Set the top by using a straight edge. As you move each cam you will see the angle between the ruler and the cam block dissapear. Just make sure your valves on cylinder one are pointing in the same direction.

[92E34]

I almost forgot. You can make a flywheel lock out of an old 3/8ths drive extention. Put it on the grinder and take about 3/32nds of an inch off the square drive. Or you can use a 5/16ths diameter bolt.

[Wiseguy]

I'd absolutely use the Cam Locks! If the car is a Non-VANOS car, then it is much simpler and easier to do than with a VANOS car. VANOS equipped cars require a few more special tools.. get the VANOS timing wrong and you can damage the engine.

Bill

[Ferret]

Bah the three I've done on non-vanos M50s didnt need more than a straight edged steel ruler and a bit of patience :)

[Hallmark]

The Bentley is very good for disassembly. Reassembly is a little trickier since they guide you to just after setting the VANOS timing and then give the ol "assembly is the reverse of disassembly".

One thing I did was take digital pictures at every step as I took it all apart so I would have a handy reference on putting it back the way it was. I didn't use any of the special tools and I found that there is a four pack of torx sockets available at Autozone for about $8 that covers everything you'll need for the job.

[rob101]

I'd absolutely use the Cam Locks! If the car is a Non-VANOS car, then it is much simpler and easier to do than with a VANOS car. VANOS equipped cars require a few more special tools.. get the VANOS timing wrong and you can damage the engine.

Bill
yeah i got the non-vanos, anyway my plan is i'll either fix her or sell her when 275 000 km comes up. Probably fix it, the market for selling e34s is going south really quick atm in australia prices are taking a dive.

[grave77]

that applies to most E34s, new models appears and it makes our rides worth less, I got personally stunned when I read about the new 335 6-speeds manual bi-turbo !! 400N/m @ 1500 RPM ... 5 sec 1 - 60MPH ........... after all it's good experience to give it a try ... I had loads of fun doing my M30 engine head ..

[rob101]

that applies to most E34s, new models appears and it makes our rides worth less, I got personally stunned when I read about the new 335 6-speeds manual bi-turbo !! 400N/m @ 1500 RPM ... 5 sec 1 - 60MPH ........... after all it's good experience to give it a try ... I had loads of fun doing my M30 engine head ..
well i once read that if you buy an e34 you get a bmw for life, they hardly ever rust and are very solid motorcars. I know that my e28 is ridiculously cheap and will waste almost any other NA 6 cylinder commodore or falcon up to the current generation.
I had to laugh that i priced up insurance online and it was 1100 per year for a 1984 520i. Now let me put that in perspective that kind of car would be about $2000 for the whole car!
After driving my e28 for a few weeks until i am confident that my coolant hose woes on my e34 are fixed i realised that, its criminal the kinds of ******** you have to go through to sell these cars and the prices they have in Australia. I mean seriously 10 000 in this country (which was the cost of my e34 about one and a bit years ago) is what you buy mid 90s commodores and falcons. And there is no difference in technology levels except bmw can actually design and develop a car that is a much better overall package. Not to metion $2000 i paid for my e28 which gets me there time after time and is more luxurious and quicker than most cars i have driven in. You can't even get a datsun 1600 for $2000 now! I am starting to think i should just keep these cars until they die as the 2nd hand market is such a load of BS.
Not to mention that e36s are still 15000+ and about 28000+ for a e36 328i. and don't worry about e92 they are about $100 000 for a 335i here

[grave77]

well that makes u turn into a bimmer collector ... it does worth every penny u spend after all ... I cant sell my old E34 even that it needs few Ks for maint. I just feel like keeping it and a void all the scond hand market BS as u can call it.