M42 engine swap: e36 to e30

Need technical Q/A then you're in the right place

Moderator: martauto

Post Reply
User avatar
mark_i
E30 Zone Regular
E30 Zone Regular
Posts: 970
Joined: Thu Aug 10, 2006 11:00 pm
Location: Widnes

Thu Jul 24, 2008 10:15 pm

OK, my e30 m42 head/valves are lunched.

Got the chance to buy a complete M42 from a 1994 e36.

Apart from the sump, the biggest problem appears to be swapping the crank damper because the e36 uses a flat profile water pump/alternator belt , e30 is V-belts.

Any thoughts on the reality of correctly changing the damper between the two engines?

Thanks, Mark
bene30jane
E30 Zone Regular
E30 Zone Regular
Posts: 286
Joined: Sat Jul 19, 2008 11:00 pm
Location: margate, kent

Fri Jul 25, 2008 9:46 pm

i have just put an e36 m40 in to my e30 and had to swap all the pulleys as the position of the crank sensor missed the pick up teeth on the pulley, dont know if thats any help?....
User avatar
mark_i
E30 Zone Regular
E30 Zone Regular
Posts: 970
Joined: Thu Aug 10, 2006 11:00 pm
Location: Widnes

Fri Jul 25, 2008 10:15 pm

Thanks.

Swapping the pulleys is the easy bit... what is difficult is making sure the e30 crank pulley/damper pulley is correctly installed on the crank as the M42 assembly is balanced in the factory.
Omi
Witty custom rank.
Posts: 1478
Joined: Sun Jan 09, 2005 11:00 pm
Location: Darlington, North East

Fri Jul 25, 2008 11:24 pm

Why not keep the superior belt system complete? I recall TimS has done this, I'll point him at this thread for input as I'm not sure what's involved...
...or is it?
User avatar
mark_i
E30 Zone Regular
E30 Zone Regular
Posts: 970
Joined: Thu Aug 10, 2006 11:00 pm
Location: Widnes

Tue Jul 29, 2008 4:52 am

Thanks Omi

Possible, but I'm annoyed that the breaker is now lumping up the price to charge extra for the PAS pump, alternator and AC comp.
bene30jane
E30 Zone Regular
E30 Zone Regular
Posts: 286
Joined: Sat Jul 19, 2008 11:00 pm
Location: margate, kent

Sun Aug 17, 2008 9:36 pm

swap the pulleys with your original ones inc the alternator
ImageImage
uzdubmwe30
E30 Zone Newbie
E30 Zone Newbie
Posts: 194
Joined: Mon Jun 19, 2006 11:00 pm
Location: nottingham

Sun Aug 17, 2008 9:44 pm

OR just get a replacement second hand head, get it skimmed and do the head gasket? (Have one here)

Im putting a 1994 lump into mine and am using the single serpentine belt setup as it's 20 times better.
bene30jane
E30 Zone Regular
E30 Zone Regular
Posts: 286
Joined: Sat Jul 19, 2008 11:00 pm
Location: margate, kent

Sun Aug 17, 2008 9:47 pm

problem i found with my e36 engine was the crankshaft position sensor sat away from the pick up ring?.....
ImageImage
Post Reply