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1,644 Posts
Discussion Starter #1
Right... As a good few people are considering or doing M52 swaps in E30s, I thought I better do a separate thread on the engine swap on a friends 325i Motorsport cab.

I've decided to put it all into 10 steps and consecutive posts so easy to follow rather than bits spread over a few pages.

I'll update each post as soon as I get time for each and more so.. photobucket uploads all the pictures and I resize them all :eek:

Part list preparation and sourcing:

Engine fitment:

E36 M52b28 engine ('95 E36 328i donor complete with nikasil liners and no, I'm not worried about them:))
Complete with exhaust manifolds, loom, ECU and EWS, keys and as much other parts as possible... Engine dropped out of a car attached to subframe with rack all still connected and as much of exhaust system as possible would be ideal if buying one.

If buying just the engine, breakers on here like Ben O'Brien and Dav-G would be able to supply more or less everything you need.

E34 525 24v sump, oil pickup pipe & dipstick tube - Got this these from Ben at Em Techic:)

E34 M50 sump gasket set
M50/52 exhaust manifold gaskets
E34 M50 inlet gaskets (only if using M50 manifold)
Found it easiest and as cheap to buy full sump and head set from Barrysmotorsport or other motorfactors or engine shops rather than all individually from main dealer

Clio bosch servo - any plastic winged Clio in a scrappie as for the sheer shits and giggles I inquired how much a new one would be from Renault.... 300 fecking euro plus VAT. Bit of paint on a rusty one with a good vacuum will do just fine me thinks :)

E28 M5 rubber engine mounts- Barrysmotorsport or main dealer

E21 323i rubber gearbox mounts (optional)- BMW part: 23711109173
New E30 325i center prop bearing (optional if old one seems ok) - BMW part: 26121226723 for facelift, 26121225152 for pre-facelift - Barrysmotorsport or main dealer

E30 lightened 5.9kg 325i flywheel
E30 325 Sachs clutch kit - Barrysmotorsport
E30 325i Starter


Use existing M52 dual-mass clutch and flywheel and live with it being slower and not reving like a bike engine :p


E30 325i Sport gearbox (not essential but nice to have over normal 260)
Modified E30 gearbox mount and 325i linkages

E36 328i shift lever - donor vehicle
Z3 1.9 shif lever - BMW part: 25117527252

shift lever bearing - BMW part: 25111220600

E30 325i Spigot bearing (Only if using an E30 gearbox) - BMW Part: 11211709681
E30 325i prop rubber coupling (optional if old E30 one is ok - Barrysmotorsport

3.64-3.91 LSD
Going using a 4.1 and M42 box on another M52 soon so will let people know how that goes :D

If using E36 328 gearbox

Modified E30/E36 prop shaft (shorten and swap on gearbox or weld on different flange to prop
E36 328i prop-shaft with E30 center bearing reversed
E30 M3 prop-shaft

E36 gear linkages

Same flywheel options as E30 gearbox

2.93-3.64 LSD

If using E30 M42 gearbox

E30 320 prop-shaft
E30 320 gear linkages and replace all bushings on these if needed

Same flywheel options as E30 325 or E36 328 box

3.15-4.1 LSD

If using E36 M3 Evo or E46 M3 6 speed gearbox

Custom gearbox mount,
Modified gear linkages,
Modified E36/E30 prop shaft or modified E36 328 or E30 M3 prop-shaft.

Exedy or Fidanza clutch and flywheel kit or Lightweight M3 flywheel and E34 M5 clutch or custom clutch and flywheel if using E46 box if not using standard clutch and flywheel for either box.

Same flywheel options as other gearboxes mentioned will work with E36 Evo box but not with E46 one.

Steering upgrade

E36 steering rack - Donor vehicle
E36 rack conversion kit - me:p
Solid straight steering shaft spline - Danthe
E34 steering U-Js x2 - scrap E34s

New E30 complete track-rod ends (E36 is slightly better in my opinion but Daithi already had these in the boot of the car ready to fit)


New E36 328 air con rad - Barrysmotorsport
Second E30 drivers side rad mount - BMW part: 17111709333
E30 brown temp sensor (to give the E30 clocks a reading) - BMW part:
E36 318ti air-con fan temp switch - BMW Part: 61318361787
88 degree thermostat - Barrysmotorsport
KMP metal impellar waterpump - Barrysmotorsport


E30 4 clyinder wiring loom cover parts -

Various pins for C101, shrink wrap, solder, wiring and general boring stuff like that:)

Will think of more bits and add them to this post as I upload pictures and remember what we used as alittle late now.

Lots of shiny bits and nice little boxes.

Clio found in scrappie so servo removed from that
The French actually had their thinking caps on for this one as you can remove the whole pedal box from inside the car and get the servo out.... Of course we realized this after we had given up on trying to get it out through the engine bay :rolleyes:

E34 U-J removed from scrap 525tds (having a turbo manifold made things nice and easy for access here)
Of course you need two of these joints so another had to be sourced so I just used one I had at home until I find a replacement


1,644 Posts
Discussion Starter #2
E36 strip down and removal of necessary parts:

Will put pictures of stripping the 328 and what we are using from it in here

Start with a prefectly good E36 328 (build date June 96)

First we went about removing the BMW alarm system from it. Didn't need to but we thought it be nice to seperate it ou anyway and still see if it started after it as if it didn't we hadn't much business removing and refitting the whole engine and EWS into another car :p

Abit of snipping and un-plugging....

And we ended up with this out on the ground :)

And the car actually still run too which was a bonus :D

Next we started taking out the engine or at least get access to it.

After takling a few bits off, we drove it out to let off the Air-con gases to avoid suffication in the garage :eek:

Back in for more ripping.

Luckily E36s are very easy to pull engines out of as the whole front end comes off reasonably quickly and easily

Our aprentice looking on

EWS and ECU parts removed from car

Have a diagram of where they are in the car on my laptop at home so I'll put that in here too

Should end up with something like this


1,644 Posts
Discussion Starter #3
E30 strip down

E30 strip down and removal of parts needed from engine/gearbox, chassis etc

Same as previous post really expect doing it to a better car but inferior engine:)

Not really anything special here really other than ripping off the bonnet, grilles, rad etc to gain access to engine.
disconnect loom engine loom from car.
Remove exhaust, prop-shaft, gear-linkage, engine and gearbox mounts

One last picture of it as a 325i :)

This is the colour the oil should be if you think there is something pretty wrong with an engine :eek:

M20b25 engine ready for its next job if Daithi brings it back to sea for an anchor for the ship :D

325i Sport gearbox removed and cleaned up as best I could for new engine

Started like this covered in oil complete with broken gearbox mount but new seals were already fitted recently when it was fitted so once cleaned up it should stay that way :)

Ended up like this. Still not immaculate but it would have to do


1,644 Posts
Discussion Starter #4
E36 M52b28 engine preparation

Will put pictures and details on stripping down M52 engine and fitting various new parts needed

Gearbox and manifolds removed

ZF 5 speed gearbox in good condition but not being used in this conversion as we already have a 3.64 LSD

E36 328 dual-mass flywheel and clutch removed as will be using lighter and more responsive E30 unit

Standard M52b28 tubular stainless exhaust manifolds

M52b28 inlet manifold. This is the restrictive one but as we didn't have one at hand and thought it best to put the engine in as is for the time being we will be refitting it until a later date.

Engine put up on a stand to make it easier to work on

Sump removed to fit and crank scrapper removed to cut off oil-pickup bracket as this would be fouling E34 sump

Waterpump removed which was dated '08 which was still in reasonable condition
Only plastic impellar type so replaced it with metal one regardless

95 degree thermostat also in good condition but replaced with 88 degree unit

Almost ready for the E30

Using an M20b25 5.9kg flywheel on the car for two reasons:
1. A un modified flywheel just won't fit due to clearance to the rear of the M4x/M5x or S5x blocks although, some have too an angle grinder to the block rather than working on the flywheel :eek:

2. The M52 dual mass clutch and flywheel setup isn't far off twice the weight of the new setup and also the fact that dual-mass flywheels have abit of delay in them when pushing on or drifting as the shock from pulling the next gear or clutch kick is absorbed by the flywheel springs.

Here is pictures comparing a 5.9kg M20 flywheel to a standard M20 one... No comparison to the dual-mass unit as we probably had already threw it in the bin at this stage :p

Removed from stand and lightened flywheel and sachs clutch along with M20b25 starter fitted


1,644 Posts
Discussion Starter #5
Prepartion of E30 engine bay and fitting M52 in its final resting place

Cleaning engine bay, fitting rack and servo and dropping in M52

Engine bay

As M20 was "sweating" as usual to put it kindly, the E30 engine bay was very dirty with oil and grease around the chassis rails and pretty much everywhere unfortunately

Clean up of engine bay
Un-wanted brackets (such as expansion bottle, coil-pack and air-box mounts) removed and area primed (will leave final coat until very end when everything is done)
E36 steering rack cleaned up and fitted
Clio servo fitted

And this is how it looked

That was with everything fitted so will just go through a few things like fitting the E36 rack and Clio servo now.

Quick video of finishing machining an E36 rack mounting spacer (I made two 8mm and two 6mm spacers for this car as I wanted the rack to be in perfect geometry without any bump-steer issues)
Click on it as numpty here can't manage to embed it directly into the thread :eek:

While cleaning the engine bay, we removed the old E30 steering rack to make getting at dirt and grease easier...
This then left us with a slight problem of not having any control of the wheels to get the car back into the garage :p

So, cleaned up E36 rack fitted with mounting spacers, E36 PAS cooler loop, new inner and outer track-rods and custom steering column coupling

Pictures were only taken with iPhone so quality is shocking unfortunately

E30 servo removed from bulkhead

Clio servo linkage drilled to accept larger E30 clevis pin

Spacer rod made up for Clio servo and E30 Master cylinder

M52 engine fitting

Apolgies for the dodgy photo as having 120kg or so dangling above a much loved E30 isn't something you want to be doing for too long :p


1,644 Posts
Discussion Starter #6
Wiring loom, C101/X20 and EWS and other sparky bits

Pictures and details of wiring

From a E36 engine loom that would have fitted fine I suppose but it just doesn't look as tidy and original so Sean went whittling it down abit...

Pull it all out of the E36 loom and this happened

As we wanted to fit it all factory inside a new 4 cylinder wiring-cover like here on realoem

Nearly there

Done :)

If only it was as easy as copying and pasting a few pictures in reality

The chopping room floor :)

EWS and ECU routed in under dash to original position.


1,644 Posts
Discussion Starter #7

Radiator, fan details etc

Brand new E36 328 rad.
Not really essential but Daithi has had an unlucky history with cooling issues on cars he has enjoyed owning so he didn't want anything left to chance

As the E36 rad is the full width of an E30 engine bay, two drivers side rad mounts must be used

BMW part: 17111709333


Were going to use a Pacet "suck" fan but I really don't like the clearance between the M5x/S5x engines between fan and front pulley so we decided on the E36 two-stage air-con fan mounted in front of the rad as we already had it in the donor car

This will also allow us to use a viscous fan behind the rad as a belt and braces approach if the electric fan ever failed.

Need to use an E36 80-88 degree 318ti fan temp switch. Only had the 328 one and time was running out to get a new one so luckily Happy came to the rescue and I called down to him at work and swapped him a switch for a tidy blank :p

The switch in question is part 10 here

BMW Part: 61318361787

Reason we needed it was that when using the 88 degree stat, the rad was still being left heat up after the thermostat opened.
So, this means the engine has to heat up to 88 degrees and then the rad has to heat upto 91-99 degrees (along with the engine) until the fan starts to work hard which isn't ideal as you can imagine :)

You need to have the rad cooler than the engine all the time obviously or else you'll end up with the engine temp fluctuating too much as the stat opens before the coolant in the rad has been cooled to a suitable level

Fitted that and wired it behind headlamp inner cover with small notch cut out for sensor plug and wiring

To let you know everything is working as it should be, you need to use an E30 brown temp sensor to give a signal to the E30 instrument cluster.

Shown here on an M42 head

BMW part: 12621710512

This is fitted to the M52 head in the central blank already made for you as if BMW had intended so not as much messing with it as I had recently on an M44 which only has the one boss in the head.

Wired it from here back through the engine loom and C101 plug although this was done eariler along with oil level sensor while engine was on a stand to make things easier.


1,644 Posts
Discussion Starter #8
Gearbox mounting and gear linkages

Methods of fitting and details of using each type of gearbox and in this case 325i Sport Getrag 260 box

As the M20b25 engines sit at a slightly different angle to the M4x/M5x or S5x engines, we needed to do alittle bit of a modification on the gearbox mount

The gear linkages took abit of bending and heating then to get at a reasonable position and fitted the shorter shift lever.

Daithi already bought a short-shifter for it and said it was in the boot so that was sorted so wouldn't have to order Z3 bits and bushes.

Upon fitting the B&M shifter though, it was just too long so hitting the prop-shaft and terribly notchy so we fitted the one from the E36 donor

Will re-do these however when all the bushes and some more things are done on the car as it was just done quickly because of time constraints this time although it works perfectly and is probably a nicer shift than my own with the E36 gear lever.


1,644 Posts
Discussion Starter #9
Manifold and exhaust system

Modifying and fitting M52 manifolds and exhaust system

Started out with these

****Measure, Cut, tac, weld and hours upon hours later****

Modify E30 half scorpion system to suit.

More than likely will make full stainless system at a later date as this one is a little restrictive due to being less than 50mm dia. but for now, this setup sounds amazing


1,644 Posts
Discussion Starter #10 (Edited)

Self explanatory really:dance:

Finished pictures

Picture of it with Feemers' Sport before which we gave an S50 heart transplant last year :cool:

These are only from a crap iPhone camera and the E36 airbox still has to be fitted rather than the cone filter that was on the donor car but you will get the idea :)


Premium Member
3,788 Posts
Well done Dave, great write up!

Really need to put a camera in the tool box:rolleyes: :D

205 Posts
328 con

Looks the job, looking forward to seeing this is he bringing it to teh e30 meet on sunday?, any idea roughly how many yoyo'a? did it take to complete including parts & labour

I know nothing about BMW
3,038 Posts
Have just read this now.

You should put up more of the work you do! A good read, enough pics and informative!

Fair play!:cool::nod:
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