M30 Head Disassembly

[Javier]

Took my M30 head to the shop yesterday and they turned it back to me today saying they can not disassemble (Bad experiences with this head per they arguments). I fear they don't even tried.

I have the Bentley for the job, and usual tools + a lot of patience and skill. I would attempt to remove rear portions of the Roker supporting shafts (Presume I can position the Camshaft to release all pressure in each rod at a time, or push down one single spring if necessary) and then to get the Cam shaft out (only 6 valves remaining, so should be easier to control them) to continue with front portions of the rod. Is it a good schedule?

Can anyone give me hints to ease my quest? Are the rods usually that tight to make the job impossible? Any special precautions to avoid damaging the Camshaft, valves, the head itself?

[shogun]

I do not know the M30 very well, usually work on my M70, but maybe you find here some helpful info in the workshop manuals https://www.bmwtechinfo.com/repair/main/
Other links I found
http://www.bmwe34.net/E34main/Maintenance/Engine/headgasket_M30.htm
http://www.firstfives.org/faq/cylinder_head/cylinder_head_faq.htm
http://www.r3vlimited.com/board/showthread.php?t=209885
http://www.mye28.com/viewtopic.php?t=108094
http://www.bimmerfest.com/forums/showthread.php?t=55819

[BigKriss]

There is a chilton manual that describes the procedure. I can email to you.

[Javier]

Sure I would appreciate all the info available. The worse issue I found up to now, is that the Rocker Arm shaft have an internal thread M12x1, I would elaborate a puller to draw out the shaft, but couldn't find a bolt/adapter/stud or similar device to thread in there!

I'm considering to visit a shop and see if they can build for me a stud with 20 mm long thread M12x1 and 80 mm long 1/2"x20 standard fine thread, so I can pull the shaft with a nut and proper spacer tubing.

[shogun]

Here you can download a lot http://www.mye28.com/viewtopic.php?t=125390

[Javier]

Got out already one of the rear shaft. Ended up being easier than suspected, all the warning (including the ones from the shop personnel) about the Rocker arm shaft being so tight that you could even damage the head pulling them, ended in a myth.

I'm confident that will complete disassemble by the weekend and have the head for chemical cleaning and resurfacing by Monday.

[632 Regal]

The only thing I found so far, gives a pretty good idea whats involved. (with pictures)

http://bigboomblog.com/automotive/88-325i
(http://bigboomblog.com/automotive/88-325i)
Edit: Late I see I'm late but it still might come in handy.

[Javier]

This is good, not the same engine but almost, the tricks and suggestions for the whole job are there.

[632 Regal]

This is good, not the same engine but almost, the tricks and suggestions for the whole job are there.

When I first saw how the rocker shafts are installed I had to mentally figure this thing out lol. I learned a bit from that link.

[Javier]

Continuing with the HG job, need the forum experts opinion on this flaw (see picture). I fear the head gasket will not be properly compressed between the head and the block, overexposing this area to coolant. I'm considering to fill the void with Locktite red RTV using a razor blade, and let it cure before assembling the head in the block. Is it reasonable? Any better suggestions?

By the way, finally was forced to order the fabrication of the tool in below picture to pull out the rocker arm shafts. One of them came along easily using my bare hands, but the other 3 said I will not go away that easy!

Javier

[Bill R.]

Javier, use JB weld, use a putty knife and put it on as thin as possible, then after it sets up take a mill smooth file and carefully level it with the rest of the head.

[Javier]

Thank you Bill, already ordered the JB weld, seems a great product.

[Javier]

Adjusting my valves, on what is mentioned as a "cold stone engine" (Doing it with the head in the bench), I found some threads suggesting the camshaft side adjustment instead the valve adjustment, but they suggest 0.09 inches in exchange of the 0.12. I can not find in the rocker arm dimensions any justification to lower the gap to 75%. Any body can explain, or just go as traditional to avoid mistakes. I found my camshaft with the 3 front lobes (Cylinder 1 and half of the 2nd) with some damage, (up to .46 mm in the second lobe). Would like to avoid by all means over-tightening the valves to prevent oil starvation.

On the other side, I didn't noticed any wear in the eccentrics or the valve tip, that is the main reason to go to the lobe side, isn't it?

Javier

[632 Regal]

Adjusting my valves, on what is mentioned as a "cold stone engine" (Doing it with the head in the bench), I found some threads suggesting the camshaft side adjustment instead the valve adjustment, but they suggest 0.09 inches in exchange of the 0.12. I can not find in the rocker arm dimensions any justification to lower the gap to 75%. Any body can explain, or just go as traditional to avoid mistakes. I found my camshaft with the 3 front lobes (Cylinder 1 and half of the 2nd) with some damage, (up to .46 mm in the second lobe). Would like to avoid by all means over-tightening the valves to prevent oil starvation.

On the other side, I didn't noticed any wear in the eccentrics or the valve tip, that is the main reason to go to the lobe side, isn't it?

Javier

Not sure if it's just me but I don't really fully understand what you are saying.

[Javier]

Sorry Jeff, excuse my poor English.

Regarding the alternate method of adjusting M30 valves, see post #8 in this thread

http://www.bimmernut.com/forum/showthread.php/41494-M30-valve-ticking

I'm adjusting at Cold engine as I have not installed the Head in the car yet, so I have it in my working bench. Protected the valves from hitting the surface using 4 head bolts with extra washers.

This sentence is the one I have trouble with: The idea is that .009 would be equal to a .012 on the valve side if there was no wear

The referenced thread said that adjusting at the cams (lobes) is better, but I fear the 0.009" gap will leave the valves over-tight.

The picture below ilustrates the lobe damage I mentioned.

Javier

[Bill R.]

What they are claiming is that due to the rocker arm ratio of around 1.33 to one, if you have a gap of .009 thousandths of an inch at the cam shaft and then push the rocker arm down so it touches the cam the gap at the valve stem will be approx .012. I don't know if its exact or not, i just adjust mine at the valve stem anyway, if there is too much friction i replace the flattened eccentric. I set mine loose anyway. Rather than a quiet valve train, a noisy one idles smoother and i don't have to worry about burning a valve or wiping a lobe from lack of lubrication.

[632 Regal]

That's about right Bill, .009 x 1.33 = .01197

That is what I was thinking but had no idea of the rocker ratio to confirm.

Adjust them on the valve stem @ .012

[Javier]

With the rocker on hand and a Vernier, I couldn't confirm the ratio, so will go for the usual way and do as you both believe is the best.

[Javier]

Attached the comments in pdf and some pictures. I explained all the main issues I found doing the HG job, and how it was solved.