Engine swap in my E34

[ProjectE34]

I purchased my 92 525 several months ago. I also recently decided to sell my house and move back into the city. With some of the profits, I have decided to do an engine swap. budget: b/t $10k-15k

I was toying with the idea of the S62 M5 V8 swap, but have scrapped that idea. I also was thinking of doing the turbo M50, but nah.....

I have decided on the Euro S52 or S50 w. ind. throttle bodies. Anyone here done this swap? I know it is a straightforward swap, but I am wondering whether the S52 Euro motor was OBD1 in the early years. I have been told diff. things from diff sources. I am also looking into doing mods immediately like the carbon fiber intake plenum, supercharger, cams, throttle body, exhaust, MAF, injectors, etc.

Any advice, reccomendations or whatever would be appreciated. I hope to talk with some people who have done this swap.

[Brandon J]

The S52 was OBDII and the S50 was OBDI for the euro motors. If you are planning on spending that much money I have the perfect solution for you!!!

Do a US S50 or S52 OBDI conversion into the car. Obviously don't forget to upgrade the suspension, brakes, clutch (if you already have the '92 manua; tranny, it is the same asn e36 M3). Then put in a twin screw supercharger from Eurosport. Awesome kit and lots of power. http://www.eurosporthighperformance.com/supercharger.html Remember when doing any upgrade like this you have to change all the wear parts like belts, hoses, water pump, vacuum hoses.

The twin screw will give gobs of torque, even off idle and lots of HP. I have seen it in an e36 M3 and it is a very good kit. The fit and finish is amazing. It even drives quieter as the plastic intake manifold yielded the intake whining noise. Now it is gone with a hint of the charger. Active Autowerk also makes a twin screw kit.


I purchased my 92 525 several months ago. I also recently decided to sell my house and move back into the city. With some of the profits, I have decided to do an engine swap. budget: b/t $10k-15k

I was toying with the idea of the S62 M5 V8 swap, but have scrapped that idea. I also was thinking of doing the turbo M50, but nah.....

I have decided on the Euro S52 or S50 w. ind. throttle bodies. Anyone here done this swap? I know it is a straightforward swap, but I am wondering whether the S52 Euro motor was OBD1 in the early years. I have been told diff. things from diff sources. I am also looking into doing mods immediately like the carbon fiber intake plenum, supercharger, cams, throttle body, exhaust, MAF, injectors, etc.

Any advice, reccomendations or whatever would be appreciated. I hope to talk with some people who have done this swap.

[ProjectE34]

I want to do the Euro version b/c of the individual throttle bodies and double vanos. I am assuming that supercharger would do fine with the Euro motor.....

[BillionPa]

I would go Euro S50B32 too, lots more power (60HP difference!) and should already come with the MAF upgrade.


However....

you could do this:
http://www.da-motorsport.com/projeler/m3turbor/index.htm

or this!!!:
http://www.da-motorsport.com/projeler/evolutionm3/index.htm

[ProjectE34]

Now that is what the **** I am talking about!!!!!!!!!!!!!!!!!

[Brandon J]

That supercharger would not work on the euro because of the individual throttle bodies. Internal work has to be done to do fored induction like that or a brand new intake like seen in the e46 M3. Hmm, sounds like you want to go very wild and don't care about driveability as that's what happens with the turbos and even the centrifugal superchargers. The twin screw gives a very flat torque curve and builds up HP like a NA car. There is torque off idle and it's power delivery is like dropping in an S62. Check out the vids and the dyno graphs.

I know of several people why switched from centrifugal or turbo M3 to a NA set-up because of the driveability. It was even hard to modulate on the track, mostly the turbo. It would peak and break the tires loose. Not gradual at all. I have met a few centrifugal M3s on the road and they had to wait until there was boost in the upper rpms. I smoked them in my 525i, hehe at least thats what they saw.

Even in a comparison with my car with the S38 vs a twin screw M3...my car has 3.6 liters, good amount of torque all over, and individual TBs, but it still has to be revved while the twin screw M3 has lots of power all over the place and more HP at top. Like driving an S62 with the sweet I6.

Good luck with your endeavors and the planning of your project.


I want to do the Euro version b/c of the individual throttle bodies and double vanos. I am assuming that supercharger would do fine with the Euro motor.....

[ProjectE34]

Actually I do care about driveability. I am not opposed to N/A as long as I put down 400 RWHP, that is why I was thinking Euro S50/ S52 with carbon intake plenum, cams, intake, exhaust, injectors, comp., etc. I think that would get me there

[hey808]

Actually I do care about driveability. I am not opposed to N/A as long as I put down 400 RWHP, that is why I was thinking Euro S50/ S52 with carbon intake plenum, cams, intake, exhaust, injectors, comp., etc. I think that would get me there

400 wheel hp is about 480 crank hp. I don't think you'd be able to get that much hp N/A even with a euro S50/52 as your base. You'd have to make up 120-130 hp over stock which is difficult to do without forced induction. I'm not saying it's impossible, but is very difficult to do, especially trying to make it drivable on the street. To be cost-effective in the long run, you may want to consider a USDM S52 with a twin-screw blower on it. Streetable, parts are more abundant, easier to tune (1 t/b vs. 6), can run it on pump gas, etc.

[joshua43214]

Got this from the e46fanatics forum


What are the differences between the S50 and S52 engines?
The North American-spec powerplant, known as the S52, is based closely on the regular production M52 engine. Like that motor, the S52 is a six-cylinder with a cast iron block, aluminum head and four valves per cylinder, with two-stage VANOS variable valve timing on the intake strokes. Unique to the S52 is a bore of 86.4mm and stroke of 89.6mm for a total displacement of 3,152cc. The engine is rated at 240 hp (SAE) at 6,000rpm and 236 lb/ft of torque at 3,800 rpm.
In addition to the larger displacement, the S52 utilizes the following special M components:
-Ported and polished cylinder head
-Retuned VANOS variable valve timing for greater high-rpm power
-Heavy-duty valve springs
-More finely balanced camshafts
-Valve lifters, springs and spring seats with reduced mass
-Free-flowing intake and exhaust systems

The European-spec powerplant, known as the S50 B32, is a much more exotic unit. With a bore of 86.4mm and a stroke of 91mm, the S50 B32 has a total displacement of 3,201cc. Like the S52, it has an iron block and aluminum head with four valves per cylinder. However, the S50 B32 incorporates the following special features to allow it to produce an impressive 321 hp (DIN) at 7,400rpm and 258 lb/ft of torque at 3,250 rpm:
-Individual throttle plates for each cylinder
-Increased compression ratio to 11.3:1
-Advanced BMW/Siemens MSS50 engine management system able to compute 20 million instructions per second
-Double VANOS continuously variable valve timing on both intake and exhaust strokes
-Lightweight pistons
-Dual-mass flywheel
-Graphite-coated conrods
-Larger inlet valves
-Second oil pump

What are the differences between the S50 and S54 engines?
The S54 powerplant of the later M roadsters is technically an evolution of the iron-block S50 B32 unit used in all European-spec M roadsters built through June of 2000. Although the peak power and torque of the S54 (325 hp at 7,400 rpm and 261 lb/ft of torque at 4,900 rpm) are barely increased compared to the S50 B32 (321 hp at 7,400 rpm and 258 lb/ft of torque at 3,250 rpm), they share few major components and differ in many areas including:
-Increased cylinder bore to 87mm (from 86.1mm) for a new total displacement of 3,246cc (from 3,201cc)
-Modified camshafts
-High pressure Double VANOS continuously variable valve timing system with faster operation at high rpm
-Increased compression to 11.5:1 (from 11.3:1)
-More advanced BMW/Siemens MSS 54 engine management control
-Finger-type rocker arms for reduced reciprocating mass and friction
-One-piece aluminum head casting for lighter weight
-Scavenging oil pump to maintain pressure during heavy cornering


Figured it might be nice to have all the specs and differences in front of us lurkers.

My only concern would one of durability on forced induction with 11.3:1 compression ratio.

very fun to follow, keep us updated.

[BillionPa]

an S54 engine would cost considerably more to acquire (in normal situations) than an S50, and isnt the S54 ODB2?

The compression issue shouldnt come up because of the very well made iron block.

If you are worried, i would have the block, head, cams, conrods, crank, and pistons cryo treated and heat cycled.

and by those parts i mean the new high performance ones from DA.

and by the new parts they have an 8.5:1 compression anyway so it wouldnt matter!

But i would still cryo treat all the metal engine parts, because they just work better.

maybe you could coat the cylinder walls in tungsten disulfide to reduce friction to near zero.

[Paul in NZ]

wow...whats the recomended gas octane for an 11.3 or 11.5 comp ratio?.Is the s54 more driveable for all the extras for little power increase