M44 into a 1995 M42 318is
 

Bit of a newb to the M42/44 world coming from E46's.
Just picked up an October build 1995 318is with an M42. It's pretty high mileage but I can get my hands on a 100,000km (62,000 miles) M44 out of a 1998 318ti.

I know I will have to convert the M44 to OBD1 with the M42 parts and sensors which I believe is straight forward. Are there any other parts from the M42 that are better and I should carry over?

Is the head design better on the M42? Cams, oil pump? etc. Can you build a hybrid of the two out of the best parts of each or is it best to keep it simple?

Not sure how the DME and OBD is handles in NEw Zeland, but unlike the six, the conversion on te four may be a bit more complicated.

You MAY be able to "dumb-down" the later engine to OBD-I but I think "uprating" the DME to OBD-II is a better, albeit complicated, option.

I can provide the ETMs for both engines to help sort out the severity of the wiring if you are interested in looking at it closely.

Mechanically, it's not a big deal, although for the time energy and cost, you might as well go to a six...

I think the M44 profile gasket design and timing chain tensioner/setup might have been updated for the M44, but I could be wrong.

What makes the OBD1 conversion more complicated on the 4 pot? I just assumed it was straight forward since it has been done before by RBach here: https://www.318ti.org/forum/showthread.php?t=38474
They seem to mix and match all sorts of parts on M42club and get it to work as long as it has the correct OBD1 sensors so I figured it was do-able.

I already picked up the engine the other day so I'll make it work one way or another.

Going to a six cylinder is tempting but tbh I like the idea of a relatively economical racey 4 cylinder with the light weight flywheel and individual throttles. I already have two 6 cylinder cars, an E46 M3 and a M54B30 converted E46 compact so I wanted to have something a little different from those.