M42 rebuild

[Diake]

Yes, I will definitely upgrade to 360° lubrication and 360° trust bearing. By the way, do you know which bearings are compatible or need just little machining? The thrust bearing seems to fit the other half, just need a little machining on the locating tab, but it has the two oil holes that I don't want in the upper half. Do you know which model is compatible? I still have to look in details.
Concerning the crankshaft, I will try to see how much it costs and if I can find a used one in better shape for the same or slightly higher price. If not I might use the one I already have. As you said the thrust bearing is not required to be 100% spotless to work, since it operates just when clutch is depressed.

Thanks again for the support and the awesome community.

[TobyB]

Have to admit, I've never had to take the bottom of either M42 apart- try
the M42club boards, as I remember a few pretty involved discussions.

And I have learned from the M10 to not be afraid at all to drill holes in bearing shells.
Just to be careful when actually doing it!

hth
t

[econti]

Small necro - but I believe all replacement bearings now feature 360 degree thrust.

[Diake]

Small necro - but I believe all replacement bearings now feature 360 degree thrust.

yea, I looked online and all have 360° trust bearing, but what about 360° lubrication?
Moreover, while preparing the list of parts to order I noticed mine didn't come with the check valve on the head for oil return. Is it normal? should I buy it?
By the way, I ended up buying a used crankshaft which is in way better shape.

Thanks again for the support. It is really appreciated.

[bmwman91]

The oil return valve was implemented on the E36 if I remember correctly. Occasionally the oil will drain down from some lifters, causing a noisy start for a few seconds as they pump back up. Also, I do not know if the oil return parts will fit into the E30 block or not. It is not something that I consider critical to have, but if you get the parts and they happen to fit into the E30 block, that would be good to know.

[econti]

Surely 360 degree lubrication would be standard as well?

[Diake]

Surely 360 degree lubrication would be standard as well?

What do you mean? is it upgraded as standard in replacement items from BMW?

[Diake]

While cleaning the components, I noticed major rust on the block where it contacts the lower timing case.



I don't think it will be spotless just with wire brushing. Moreover, given the upgrade to e36 timing case with steel gasket, I wonder if it may cause leaks and requires machining. In case which is the maximum machinable depth?
I might consider machining also head and boring in case.

What do you think?

Thanks again

[chrisca70]

Keep us posted, very nice thread!

[Diake]

Updates:

Sent block and head to machine shop to be cleaned, checked and machined where necessary.


Painted block


Cleaned pistons



Parts arriving

I will keep you updated as soon as there are major changes

[Diake]

Finally all the parts arrived and we could proceed with the assembly.


Parts are ready


Block cleaned


Detail of the block


Oil jets cleaned


New bearings in


Plastigauge test


Everything lubed


Torqued and tightened with right angle


Rear seal on with a bit of gasket maker near the ends


Pistons and rods cleaned



All inserted correctly


Detail of the cylinders, polished but no hooning to avoid changing pistons. Small wear is still visible but in theory not so relevant.


Oil pump in, with a bit of gasket maker near the edges of the metal gasket


Ready for the head, again gasket maker near the end of profile gasket for better sealing.


Head torqued with ARP studs


Gasket for upper oil pan


Oil pan on


Valve cover painted with wrinkle black paint


Engine almost done

Unfortunately we ordered the wrong timing chain, which had a chain to be crushed but without the right tool we preferred to send it back and we are waiting for a new one.
We followed the Haynes manual for most of the procedures, but not all of them are explained. If you notice something wrong please tell us, we would appreciate it since it is our first engine build.

Hope you enjoyed the pictures and short explanation. We will keep you updated as soon as possible. Cheers

[Powling]

Great update!

[wworm]

awesome

[Diake]

The engine is finally over.



I mounted the correct chain and chain tensioner. Sorry but I was in a hurry and had no time to take pictures.

Hope you enjoyed the build. If you have any question/doubt just comment. Any suggestion is welcome, especially before starting it ;)

Cheers

[bmwman91]

Good work. Did you take the oil pump cover off and pack the rotors with some grease? Occasionally, the pump will not prime itself after being dry for a long time, causing the engine to have no lubrication. A couple of people on here have had that issue after a rebuild.