Time for an Upgrade, Stick to m20b25 or go M52b28?

[e21rana]

Im in limbo between sticking to my current m20b25 engine or upgrading to a e36 2.8 engine. Truth be told I want to go faster but naturally aspirated, i don't want to go down the turbo route (not just yet anyway) I want to do something nothing too challenging and fairly easy to do. Converting the 2.3 to the 2.5 was easy.

If I choose to stick with my current engine my future plans for it would be:
Upgrade the injectors (pink e36 injectors)
e28 3.5 AFM or Miller Performance MAF
Ecu Chip
Schrick Cams
RHD Race Engineering ITBs

But I'm just wondering if there's any point doing all this just for a few horses.

If theres anyone or you know on this forum done a e36 2.8 conversion can you please shed some light. Im finding it hard to search not this conversion.

File 10-09-2016, 5 48 45 pm by Ranvir Singh, on Flickr

[Jeroen]

I believe that you can expect approximately 220 BHP if you do a 2.7 litre ETA conversion on that M20 with faster cams, high capacity injectors etc etc if you don't want to go into extremes and keep a driveable and durable engine.

Contrary to what BMW's specs tell you the average well maintained M52B28 -that can be had for peanuts- will give you 210 BHP, easily, when new figures were tested to be 215-219 BHP according to reliable Auto Motor und Sport tests. So pretty much the dame for a small fraction of the price of a full M20 conversion with pretty easy upgrades like M50 intake and a custom chip as options as well

M50 and M52 conversions are pretty common and several people on here have done this, hope they are willing to shed some light on this.

[e21rana]

Thanks for your reply.

Just wondering if someone has a thread or post with the things I'll need for the conversion?

Does the m20 5 speed gearbox bolt straight on?

[Moutinho]

i also want to do that swap, i own a 1979 320/6 and want to get about 200hp, so the m52b28, is the best choise, cheep and easy to upgrade. Also wondering if someone has a thread or post with the info for the swap!
my mechanic says that my m20 5 speed gearbox is a straight bolt on, and the major things are fabrication of the engine mounts or get the e28 m30b35 engine mounts ,get the m50b25 sump, new radiator, new fuel pump and other small things...
my goal is to achieve 210/220hp in an non turbo engine, so upgrade for a m50b25 manifold and chip tunning will do the job, i guess!

keep us updated if you already started your swap!

[Mihajlo]

just thinking about M20B28 with some ITB's

M20 fit's more nicely in E21 than M5x

M20 gearbox will direct fit to M5x but angle of it will not match.
and M5x gearbox have 5th 1:1 (not overdrive like M20 box) so you'll have to worry about diff also if you don't want 100mph top speed