Yet another engine swap thread (no, not an m3 motor) need opinions

Lately ive been redoing a lot of things on my car as ive decided to keep it (ive owned it outright since day 1 and no car payment is nice) . All thats left is the motor which leaves me with a bit of a problem. I cant make up my my mind on what i want to do.

I originally was going to do an s52 frankenmotor but put that idea aside due to potential reliability issues.

So what ive been considering is the following:

M52tuB28:

-M54b30 intake manifold
-M54b30 throttle body (if i can)
-port/polish head
-long tube headers
-custom catback/cutout
-dinan cf long tube intake
-cams (possible)

Or

M54b30:

-long tube headers
-custom catback/cutout
-dinan cf long tube intake
-port/polish head
-cams (possible)

Im also going with a 3.46 diff

Upside to the 2.8 is i can get one for half the price of the 3.0


Which would you go with?

m54

what engine and mods do you have now?

M54B30. Why would you consider going with an S52? M54B30 uses the same crank, conrods, and pistons but with added refinement and practicality of double vanos.

S52 franken would be the best of all,but it would be a bit more difficult.
Id say m52tbu28 would be your best bet. VERY Easy swap,cheap cost and easily available.

Sent from my X10a using Bimmer App

S52 frankenmotor would be interesting. I think I saw someone here modify the head to accept a double vanos unit.

I got a 2005 m54b30 with 79k miles for 1800

What's wrong with your current motor? If I were going to drop that kind of coin on my E46 I'd use it on a limited slip diff.

My current motor is am M52tuB25 with 184,450 miles. Lsd isnt a necessity. The porsche cayman has an open diff and does just fine.


I just want a quick revving, peaky, high compression motor that breathes and screams in upper rpms (yes i described the s54 but its not going to happen as im not spending 8k for a swap)

Problem with the s52 is reliability if i try to put dual vanos on it. And to have it done isnt cost effective. If i could put it in as is that would be great but idk how im going to handle the electronics. So too much of a headache.


Is it me or do the m52's rev a bit faster and sound a little meaner? Doesnt the 3.0 have lower compression than the 2.8?

I don't know, my 318's had LSD and I think it was worth it's weight in gold, the car just feels much more capable with one, also more fun

If you're set on a swap, I'd go M54B30, but I still say LSD and then maybe throw a supercharger or turbo into the equation and run that until your motor blows (which could be a long time later) then swap for the M54 and put your FI kit onto that.

Sorry but no F/I for me. Its a daily driver and i prefer N/A. Reliability is a factor as well.

Originally Posted by ///M=Power

Sorry but no F/I for me. Its a daily driver and i prefer N/A. Reliability is a factor as well.

S52 E36 M3 w/ M50 manifold swap, injectors, maf, headers, tune, and full exhaust.

^That's a good plan too! And I think everyone prefers NA until they own something with FI...

Originally Posted by E46Mango

S52 E36 M3 w/ M50 manifold swap, injectors, maf, headers, tune, and full exhaust.

That would be nice and all buy what about the electronics. Thats why i said no m3 motors.

Originally Posted by ///M=Power

That would be nice and all buy what about the electronics. Thats why i said no m3 motors.

No i mean the whole car. it's a better setup in general if you want to track. no subframe mounting problems... but you do have other areas to reinforce such as the rtab pockets

what mods do you have now on your 323i ?

Originally Posted by Alex323Ci

what mods do you have now on your 323i ?

Bolt-ons. intake / exhaust / tune etc.

Originally Posted by ///M=Power

That would be nice and all buy what about the electronics. Thats why i said no m3 motors.

I think you can run it off the stock ECU if you move some of your stock sensors over.

If you don't add the exhaust VANOS, you can probably just tune it out (Alpina does it afterall).

If you do add the VANOS, you can keep the wiring harness completely stock. You'd still have to tune it for the extra displacement and such.

Originally Posted by TerraPhantm

I think you can run it off the stock ECU if you move some of your stock sensors over.

If you don't add the exhaust VANOS, you can probably just tune it out (Alpina does it afterall).

If you do add the VANOS, you can keep the wiring harness completely stock. You'd still have to tune it for the extra displacement and such.

I wish I knew someone who could make it work. I was talking to the guys at active autowerke about it and they said it would be a pita and never been done...

Originally Posted by ///M=Power

Bolt-ons. intake / exhaust / tune etc.

if a lot of them then stay M52TU and go 328 2.8L engine.