318iS or 328 conversion
Moderator: martauto
My tourings got the 318is lump, very easy to swap from M40 to M42. Its a much better engine than the clattery old M40, reliable, economical and nippy. A good upgrade but its not a 2.8 6 cylinder in terms of speed obviously. A well done 2.8 conversion will cost £££ as has been covered on here many times.

- Brianmoooore
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If you're looking for a daily driver, with respectable economy, then a touring with an M42 is a nice proposition. Obviously not in the same performance class as a 2.8 24 valve, but a nice enough conversion, especially if insurance costs come into the equation.
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'89 325i Touring | Touring Resto Thread | In-Dash Screen install
Ive got an m44 in my touring,mechanically the same swop as m42 but you have a bit more work electrically ie ews and you have to convert the e36 wiring loom similar to m52 wiring.
Been on the road 5 months now and very happy with it,much better than the m40.
Been on the road 5 months now and very happy with it,much better than the m40.
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- E30 Zone Wiki / Team Member
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You can keep your m40 gearbox and prop, the m42 box has just got a different 3rd gear ratio. I left my box/prop in place, pulled the m40 off it and put the m42 straight back in its place. Beware you may need to change the spigot bearing in the end of the crank if you do this.
An e36 m42 loom will need adapting, similar to doing an m52 conversion. You will also need to change the sump but can use your m40 sump from the old e30 engine. You will also need to find e30 m42 exhaust manifold and exhaust system.
Also read Thinking of fitting an M42?in the tech help m40 / m42 page . I fitted m25b solid motor mounts to mine with m40 arms and where they may be OK for a track day car they are way too hard for a daily driver .
I'd go 2.8 if insurance isn't a problem especially with a Touring with it being abit heavier so the extra torque (and there is alot of it) from the 2.8 would be an advantage.
Also, A 2.8 with the right choice of gearing will do just as good fuel economy as an M42.
Not that the M42 isn't a nice swap. Did one for a friend and it made it a lovely car but the M52 is just in different league especially with a few mods
Also, A 2.8 with the right choice of gearing will do just as good fuel economy as an M42.
Not that the M42 isn't a nice swap. Did one for a friend and it made it a lovely car but the M52 is just in different league especially with a few mods
M42 rightness above 6500rpm, nobody can hear you scream
- hillbilly30
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+1Dave_M3 wrote:I'd go 2.8 if insurance isn't a problem especially with a Touring with it being abit heavier so the extra torque (and there is alot of it) from the 2.8 would be an advantage.
Also, A 2.8 with the right choice of gearing will do just as good fuel economy as an M42.
Not that the M42 isn't a nice swap. Did one for a friend and it made it a lovely car but the M52 is just in different league especially with a few mods