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m42/m44 conversion
Posted: Thu Jun 07, 2012 12:17 am
by Irish_chris
will i have much trouble fitting a m42 or m44 engine into my e21 316 if i have a full e36 318is there for the parts?
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 12:41 am
by e21-Mark
You'll be needing some 320/323 parts too, such as gearbox and engine mounts. Sump will need altering to fit, as will exhaust manifold iirc.
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 12:51 am
by Irish_chris
by 320/323 do you mean e36 or e21?
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 6:44 am
by e21-Mark
e21.
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 7:18 am
by Jason_323i
And an m52 is not that much more work
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 9:05 am
by e21-Mark
and Nas is selling all the bits you'd need.
140 brake or 220?

Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 9:16 am
by Duracel79
I think he's trying to keep the weight of the engine as close to the original M10 as possible.
He'd be gaining ~20kg going to an M42 and ~35kg to an M52.
My money would be on the M52, I think its an easier conversion and the sound of a six pot is king
Ben
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 10:30 am
by Irish_chris
Duracel79 wrote:I think he's trying to keep the weight of the engine as close to the original M10 as possible.
He'd be gaining ~20kg going to an M42 and ~35kg to an M52.
My money would be on the M52, I think its an easier conversion and the sound of a six pot is king
Ben
This man is spot on
Looking to put the 140bhp from an e36 318is
Itll be hard enough to find an e21 323 gearbox :/
At the minute ive no engine or box so may aswell do something half decent
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 2:13 pm
by e21-Mark
Why so hard to find a 320/323 gearbox? You'll be needing one for either engine anyway, unless you fit a later box and change to a leccy speedo?
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 2:48 pm
by Irish_chris
e21-Mark wrote:Why so hard to find a 320/323 gearbox? You'll be needing one for either engine anyway, unless you fit a later box and change to a leccy speedo?
is there many about? honestly im finding it quite hard to find local parts (northern ireland)
ok so i need:
320/323 box
engine mounts
much else? other than engine/loom/ecu will i have to swap anything else?
car in question is a 1983 316i
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 2:54 pm
by Jason_323i
For the m42 you are on your own to make the engine mounts, we need rob to chim in as I think from his conversion the thought the m42 would work better with a 6 cly subframe.
You will need to modify the m42 sump and exhuast and you only need the e21 6 cly box if you want to run the orginal speedo. also you will want an e30 318is fuel pump to retro fit to the e21 tank, and may have to move the battery to the boot to clear the inlet manifold.
Also I would look to fit the rad that comes with the m42 and you want an e30 m42 for the sump rather than a e36 m42/4
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 3:31 pm
by e21-Mark
My old track car used the 6 pot subframe.
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 3:50 pm
by Irish_chris
e21-Mark wrote:My old track car used the 6 pot subframe.
typical, ive been hunting for a 4 cyl subframe just to get my car home as the previous owner misplaced it but its too late now as he rang me this morning to say he got sorted with one
looks like ill be keeping an eye out for an e30 318is rather than e36 then, pity as they are demanding higher money lately
Re: m42/m44 conversion
Posted: Thu Jun 07, 2012 3:58 pm
by Jason_323i
e36 motor will do you just need the sump from a e30 m40 or m42
Jason
Re: m42/m44 conversion
Posted: Fri Jun 08, 2012 1:33 am
by rob0r
Pretty much all as above.
Option 1: No speedo
Engine, E30 sump, M42/M40 gearbox, custom gear linkage, E30 318is prop (custom prop mounts in trans tunnel), either subframe, custom engine mounts/subframe mods, M20 fly and clutch, E30 M20 starter
If you keep the gear linkage straight you won't need to mod the sump. Bad news is that you won't have a speedo, but you could bastardise an E30 speedo clock into your cluster with a custom chopper wheel setup
Option 2: Speedo
Engine, E30 sump, E21 M20 box, E21 M20 prop, E21 M20 gear linkage, either subframe, custom engine mounts, M20 fly and clutch, E30 M20 starter
Keeping the linkage/box straight will tilt the M42 more vertical and this will make the sump mods necessary. Everything else is much simpler IF you can get the bits, which these days will be costly.
Other considerations:
Custom exhaust, E30 in tank fuel pump (if carb), return fuel line (if carb).
I'll be doing this again and based on what I have laying around at the time.