N12/N16 Engine Swap with N18
 

I wanted to start this topic in case someone out there is thinking about other options about their N12 or N16 engine.

In the previous series found here, I got the project done with success. I stopped short of marrying the N18 ECU to the N14 CAS because I decided to rebuild that engine and swap it back, I also was not able to economically have them married.

In this series, I will be reusing the N18 on an N12 Hardtop. For this combo, I will try to copy the old ISN and write it to the N18 ECU.

I will be updating this first post (#1) so members don't have to scroll or miss anything and the subsequent posts will be for comments, inputs, and update notifications.

Car: 2007 R56 Base with N12 Engine and Automatic Transmission

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Prepping - Day 1

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Prepping continues...

I used newtis.info to create this spreadsheet to map out the pin assignment. Color matching means swapping wires from N12 to N18. This is only on the body side connecter leaving the ECU.

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N12 1-stage cooling fan

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N18 2-stage cooling fan

https://cimg0.ibsrv.net/gimg/www.nor...df37000c27.jpg

Some more work done...this is starting to take shape :)

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A bit more over the weekend..

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Saturday (02/01/2020) was the day :)


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Installed the turbo and rear plumbing.
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installed the front nose (from a Cooper S)
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wiring for the S cooling fan. I could've spliced the wires but having this harness make the job cleaner.
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adding stage 2 cooling fan power
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left: new wiring to the rad fan. Right: old connector.
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rad fan main power line
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rad fan ground
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plug to modify
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adding stage 2 cooling fan signal to N18 ECU
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Adding stage 2 cooling fan relay
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rewiring the ECU body side plug
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leaving the original fan plug on the side and connecting the new one to the new fan

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Took the mini for a 50 miles test drive. other than suspension and exhaust noise, the car was fast and responsive. Some of the things I need to work out are at idle it sounds like it has a minor vacuum leak and as you notice my speed is 73 at 2900 rpm. My N14 was 80 at 2700 rpm.

The swap
 

if you are referring to the N14 with N18 swap, it was not a lot of work. Swap the engine and harness. add two wires to the plug that goes inside the car, marry the ecu to the car, code the CAS to remove N14 and add N18 engine codes.

Cas
 

Car Access System also known as Immobilizer. under the dashboard.

Cas
 

I know this may sound criminal to some, but could you go the other way from a N18 to N16? Looking forward to this thread. Great job getting passed the immobilizer.

I don't see why not.

still waiting to sell one more mini to buy another one for this project :impatient:

Sounds like a small (mini :) ) obstacle .....

Just lost a good donor for this project :cry:

sit tight til i find one :mad:

back on the search...

Hey, I know this thread is a bit old, but I have an r56 N16 and want to go to an n18. Has there been any updates on this process? Cheers

I got sucked up in flipping minis these passed a couple of months. I know engine wise, it is a bolt on. when I had the N16 clubman, I noticed the fan wiring was different and maybe the radiator support is also different since there is no intercooler. I have an N14/N18 nose assembly that I could use. but that is something to consider for others. Also, the fan wiring is different and there need to be some additional wiring coming that way. I forgot to mention the exhaust system of the S is bigger than the Base. Hood scoop may not be an issue, but I could be wrong.

I will see if I can get back on this project sometime soon. but what phase of the process are you at?

Currently in the consideration phase, I have found a few mid-mile JCW N18 engines here in Aus, also apparently you would need to replace the bonnet as the hood scoop actually does cool the turbo, even though it's a dummy scoop, and also that the DMS would not recognise some of the readings from the engine, and possibly CAS and ECU troubleshooting. Are the tranny and engine mounts the same however? I would think they are

Used JCW engines seem to go for around $4-7K AUD which is like 3-5k USD
Cheers,

yes, the engine-transmission mounting points are the same. In the case of countryman and paceman, even though they are turbo, they don't have hood scoops. So not sure if the cooling is that effective from the hood. When you swap the N18, you'd need the ecu along with it any maybe the fuse box, the one inside the car. Realoem.com points to two different part numbers for the automatic transmissions. Not sure if the "base" can handle the "S" power increase. My N14 to N18 swap was done on a manual transmission which was fine.

i found two possible clubmans for the project but they're not going to auction yet.

The engines I looked at would have to have the transmission attached as well as the justa gearbox could no way handle the power increase.

If you end up doing an N16 swap with a n18 I would be very interested in how you would do it

Cheers

Yeah, it will interesting. The donors I'm looking at have automatic transmissions. I'll keep it just to see how it would react to the new engine. My N18 isn't a JCW but for sure got more juice than an N16. I told my wife that you reignited the urge to do this swap lol. It's just I have a flock of minis in my yard I need to sell :)

In all honesty doing this swap and documenting it would probably be making history for a lot of justa owners, that probably bought their minis really cheap and want some more performance. But yea definitely keep this thread updated if you continue!

Cheers,

Following just for future knowledge

Just to build some anticipation ;) I think I found the perfect donor. I am trying to get in touch with the owner/seller before someone snatches it from me. It is a 2007 R56 Base and surprisingly fully loaded! wish me luck :)

Finally...scored a nicely optioned R56. The donor engine needs a bit of fixing but not a biggie.

Stay tuned :)

Note: all updates will be in the first post of this thread.

Apologies for being dumb headed but your usage of the word "donor" got me a bit confused. You now intend to take out the N12 engine from the 2007 Base car and replace it with an existing N18 engine, right?

On the basis that my assumption above was right:
That thread title implies that an N14 engine is replaced with an N18 one. For the sake of future web searches, please consider opening a new thread with a fitting title (i.e. replacing an N12 engine with an N18).

By donor car i meant a donor for the project as in experimental car. Same with an N18 engine being "donated" for this cause.

I initially wanted to do an N16 swap but couldn't find a car for this purpose. Also, since the N12 is VERY similar to the N16, i added a subtitle indicating that. In the desktop view you'll see that in the first thread.

As for the N14 swap, not sure if that was a typo, I have seperate thread done for it.

I hope this explains the intent.

OK, thanks.
Regarding "N14", no, no typo. I thought you intended to use your thread "R55 '08 Clubman S with '12 N18 swap" (to which you linked to in the first post of this thread). Now I see that you meant the first post of this thread with "first thread".
All clear now!
:-)