About to do cylinder head swap...questions

[Bonzo]

Hey everyone!

I've been frequently consulting this forum but had yet to join until I had a question I couldn't find the answer to. That time has now come, and I am proud to be joining with you all!

THE ISSUE:

I was having overheating issues followed by that all-to-familiar sweet white smoke coming out of the tail pipe. Sadly, instead of a blown head gasket or TCPG, there was a small crack near one of the valves in cylinder #2. Not repairable, or at least not at any of the machine shops around here (DC).

My question is two-fold:

1. Any PARTICULAR recommendations for sourcing a new cylinder head? I used the FAQ on this forum and have located a few places that say they have the part. I was just wondering if anyone here would go out of there way to recommend a particular supplier?

2. I followed the bentley manual as well as Tim Thurber's write-up on removing the head. I have my chains wired tightly to the cam sprockets and made markings to get the re-assembly exact, assuming I would be putting back the original head. Now, if I buy a replacement head described as "complete rebuild with cams and tower", should I expect to have to adjust the valves when I install the new head, or can I just place it down with the new gasket and assume its good to go?

Thanks in advance for your patience and help!

[Geoff]

You have to have the bottom end set at TDC (#1  piston at top of compression stroke)   this can be locked in with a dowel or a bolt on the flywheel.     Then the head needs to be set at TDC also, with both cam lobes of #1 cylinder pointing up,  and at each other,  if you know what I mean.  The cams can be locked in this position with a piece of wood with 2 cutouts in it, to hold those square blocks at the back of the cam in position.   There is more than 1 thread on this site with pics on how this looks when its set correctly.
                                  Good Luck,
                                         Geoff

[NO717]

Honestly, you can get a head for cheap, CL or ebay. The biggest thing however is you will want to pressure check the head no matter where you get it.

Here is an ad from CL in woodbridge, its not that far.

http://washingtondc.craigslist.org/nva/pts/3214471107.html

I grew up in Bethesda btw.

Also, if you have an E30 M42, a late model head is a good upgrade.

[alim_h]

Honestly, you can get a head for cheap, CL or ebay. The biggest thing however is you will want to pressure check the head no matter where you get it.

Here is an ad from CL in woodbridge, its not that far.

http://washingtondc.craigslist.org/nva/pts/3214471107.html

I grew up in Bethesda btw.

Also, if you have an E30 M42, a late model head is a good upgrade.

Hey NO717, what's the difference between the heads? I'm in the middle of swapping my cracked '91 head with a '94 head.

Also, know anything about the difference between the blocks?
And, which combinations is the oil check-valve needed? I don't think there was one in my engine (unless it fell out). And I didn't see one in the '94 (unless it fell out, lol).

[NO717]

Alim.

The main difference the the heads are,
The E30 heads had 7mm valve stems and a double valve spring.
The E36 head had mainly 6mm Valve stems and single valve springs. You will need to check the casting date on your head. Early E36 m42's had the E30 setups.

As for the blocks, the E36 block had knock sensors and provisions for the knock sensors casted on the block.

Later E36's have the updated parts that makes the early M42 ticking bombs. Updated timing covers, a deflector rail for the timing chains instead of an idler gear, and also the plastik oil pressure valve.
Again however these very in the production date of your motor.

There are two oil pressure valves in your engine, the one you are concerned about is the one in the timing case. (Not really in the block.) It is located under the oil filter casing. You can see it once the filter case is removed. (The unit it self, and not just the cap.)

The parts you want to replace are:
5,6,7,8.

http://www.realoem.com/bmw/showparts.do?model=BE52&mospid=47425&btnr=11_1120&hg=11&fg=30