330i N52 Engine Swap

[Boudreau1589]

Fellow 1ers,

I recently had the N51 in my 2009 128i blow up on me. With only 35k miles on the car and it in great shape otherwise, I've decided to keep the car and swap a replacement engine into the chassis.

I've located a few N51s with relatively low miles (not 35k low, but low) for pretty cheap money. However, before I go ahead with the purchase, I wanted to see if this is a good opportunity to extract some extra performance out of the car and maybe swap one the top spec N52s into the car instead (330i, Z4 is, X3 or X5 with 255-272 HP).

Have any of you performed this swap or know of any similar N51 for N52 swaps? I've searched this forum and the E90 forum for comparable 328 swaps but have come up empty.

With so many folks desiring the extra power and torque of the high output N52s, I know that many have attempted the tuning/DISA conversion (and seemingly all failed or come up short of the BMW figures of 260+ HP at the crank) but I would have assumed at least one of you would have performed this swap in the quest for more power.

I'm assuming some engine mounts will need to be retrofitted. My biggest concern and main hesitation in buying an N52 in place of an N51, is programming and wiring. There has to be a good reason that this hasn't been done and publicized, right? What am I missing?

Thank you!

[chris_flies]

I don't know much regarding the nitty-gritty about a swap like this. A friend of a friend just bought an N51 128i that blew a motor (RIP) after like two weeks of ownership...

The differences between the N51 and the N52 are the pistons (the N51 has lower compression) and the additional emissions equipment attached to the N51 (more effective cats, secondary air injection, etc.). The block, and pretty much everything (other than pistons and intake manifold) is the same between the N51 and N52, so mounting won't be a problem. Theoretically, it's some coding and tuning away from actually happening.

Side note: all the N52's are the same, regardless of output, it's a difference in the intake manifold and the tune.

[Boudreau1589]

Originally Posted by chris_flies

I don't know much regarding the nitty-gritty about a swap like this. A friend of a friend just bought an N51 128i that blew a motor (RIP) after like two weeks of ownership...

The differences between the N51 and the N52 are the pistons (the N51 has lower compression) and the additional emissions equipment attached to the N51 (more effective cats, secondary air injection, etc.). The block, and pretty much everything (other than pistons and intake manifold) is the same between the N51 and N52, so mounting won't be a problem. Theoretically, it's some coding and tuning away from actually happening.

Side note: all the N52's are the same, regardless of output, it's a difference in the intake manifold and the tune.

Thanks for the tips, Chris. I appreciate it. I'm hoping someone else may be able to tune in with the, "Nitty-gritty" as you put it. Those fine details are what's really holding me up.

However, it's great to know that it has been done!

[rowsdower]

Where are you located? If you’re in a state that tests emissions, this might end up being a headache since the car was originally SULEV. I don’t know for sure though. But it is certainly worth investigating before spending any money on this swap.

[smeard]

someone say... LS SWAPPPP

[NorthernDancer]

Boston is the home of a huge membership in BMWCCA; it would be worth joining to find expert knowledge from members and club (Mike Miller) plus knowledge of the better indy BMW garages. Turner Motorsport is close to you. You want it done right, the first time.

[rjahl]

Originally Posted by Boudreau1589

Fellow 1ers,

I recently had the N51 in my 2009 128i blow up on me. With only 35k miles on the car and it in great shape otherwise, I've decided to keep the car and swap a replacement engine into the chassis.

I've located a few N51s with relatively low miles (not 35k low, but low) for pretty cheap money. However, before I go ahead with the purchase, I wanted to see if this is a good opportunity to extract some extra performance out of the car and maybe swap one the top spec N52s into the car instead (330i, Z4 is, X3 or X5 with 255-272 HP).

Have any of you performed this swap or know of any similar N51 for N52 swaps? I've searched this forum and the E90 forum for comparable 328 swaps but have come up empty.

With so many folks desiring the extra power and torque of the high output N52s, I know that many have attempted the tuning/DISA conversion (and seemingly all failed or come up short of the BMW figures of 260+ HP at the crank) but I would have assumed at least one of you would have performed this swap in the quest for more power.

I'm assuming some engine mounts will need to be retrofitted. My biggest concern and main hesitation in buying an N52 in place of an N51, is programming and wiring. There has to be a good reason that this hasn't been done and publicized, right? What am I missing?

Thank you!

Spend a little time researching your parts on REALOEM. Except for the engine short block and DME tune, I don't think there is any hardware differences.

Regarding the tune, the MSV80 has been pretty well cracked so "someone out" there can probably spoof the BMW Euro 330 tune to run with the powerclass found in your CAS. Bimmerlabs?


There is very little reason why you could not swap to an N52N with a three stage manifold and run 250HP at the crank. Then take that tune to a "tuner" and find another 12-20 hp without any additional hardware changes.

What's up with this forum? a year ago something like this would have had two pages of comments by now. Have they banned all the contributing non vendor members?

[Boudreau1589]

Originally Posted by rjahl

Spend a little time researching your parts on REALOEM. Except for the engine short block and DME tune, I don't think there is any hardware differences.

Regarding the tune, the MSV80 has been pretty well cracked so "someone out" there can probably spoof the BMW Euro 330 tune to run with the powerclass found in your CAS. Bimmerlabs?


There is very little reason why you could not swap to an N52N with a three stage manifold and run 250HP at the crank. Then take that tune to a "tuner" and find another 12-20 hp without any additional hardware changes.

What's up with this forum? a year ago something like this would have had two pages of comments by now. Have they banned all the contributing non vendor members?

I know, right? I felt like this project was long overdue for this forum and I was really hoping people would jump onboard for this.

Anyway, I appreciate all of you that have responded. I have some phone calls to make and hopefully I can get in touch with a Boston-area shop that is interested in doing the work. Turner MS was a good call - It can't hurt giving them a call to see if they know of anyone who might be interested in doing the swap.

In any case, I'll document whatever I end up doing and keep you all apprised.