E30 m42 vs. E36 m42

[318idol]

Just picked up a rebuildable 1995 m42 for my 318I. What are the differences besides the intake plenum? Are the heads interchangeable?

Also, the e36 Bentley manual has nothing on the bottom end.  Is a there a factory repair manual with more info?

And, what's the best sequence to remove m42 from e30? Engine and trans as a unit? Trans first, then engine? Or?

[DesktopDave]

The motors are identical, heads and blocks. All parts can be swapped. The later E36 got a different chain tensioner setup - it has a deflection rail instead of an idler gear. AFAIK there are also three accessory belt systems too - v-belt, belt & serpentine, then full serpentine. E30 has the two-piece front sump pan. E36 has the one-piece rear sump pan.

There are a few electrical differences too - EWS DMEs - the DISA manifold (dual-resonance intake) - knock sensors. The cyl head temp sensors are combined on the E36 as well. Later E36 motors have lighter rods and thinner valve stems.

I typically pull the motor and transmission as one unit. Those reverse torx bolts are hard to undo in the car. It's also possible to drop the subframe instead of lifting the motor.

As for the bottom end, I'd use the same values as the M50 if they're listed. I did a quick Googling and found this cool site though. BMW's TIS workshop manuals online.

[318idol]

Thanks. When you refer to later e36 m42, you mean the m44, right?  Are sensor s all in the same place on.both m42s?

I want to put an e30 m42 head on an e36 1995 m42 for a 1991 318i.  Just looking for possible glitches and trouble spots. Could I call you?

[benz-tech]

ImIf you can use it, the 95 head has lighter and arguably better 6mm valves. Run the '91 cams though. The 96 and later m44 isn't the same animal,  although many parts are still interchangeable.

[318idol]

Dave, the website with the "workshop manuals" is very strange. I see no manuals, just random  tech notices, no diagrams, no photos, no texed, really. Not sure where they hide the actual manuals. Did you try to find info from the lengthy list on the left side of the page?

http://workshop-manuals.com/bmw/3_series_e30/318i_m42_sal/1_service_information/0__maintenance_and_general_data/1_si__modified_change_intervals_e9x-m3-us/