MadaboutKitcars

Hi ladies & gents and a Merry Christmas

Possibly a mad question but has anyone considered, attempted or completed a BMW Z3 engine swap to a V12?

I’ve had a look around and found that BMW themselves did such a thing as, what looks like, an engineering exercise using a V12 from a BMW 750 or 850.

https://performancedrive.com.au/bmw-m-builds-a-z3-with-a-v12-engine-0811/


They would have had a rather large parts bin to pick from.

Cheers,
Trev

The engine bay in the Z3 is big to start and designed with the straight six in mind. The V12 isn't that wide and a similar length. It is doable as BMW have proved but you would be better off and have an easier life going with the M3 straight six conversion. If you really must do it you can pick up and old 7 series very cheaply these days and between both cars you should have enough parts to make it happen. Go for it !!

Now my brain hurts! Would be wonderful with some additional chassis bracing.

Tempted to keep an eye out for a reasonably priced 750/850.
I'm looking at it as the sound would be worth the effort

As it's a BMW engine not sure if IVA would come into play.
It would be for a Tribute 250.

Easily found here. Located a good running BMW 750i V-12 for about $1000. Has 130,000 miles, no issues.

Very tempted, but lots of work to do on my 250 SWB as yet.

I might be wrong but I'm pretty sure you can swop an engine out and it doesn't need to be like for like. IVA would only apply if you modified the structure of the monocoque to accommodate it.

Lucky@Lemans You'r correct about the engine change but DVLA will need to be told and the V5 up-dated.
Also the correct details will have to be confirmed with an invoice or "statement" in writing from a reputable garage.

With regards to the BMW V12 if I remember correctly this engine uses 3 ECU's. One for each bank of cylinders and one master, which is then linked to the gearbox ECU, that's a lot of wires! !

Wow, the IVA process doesn't require checks for fitting a different engine? In New Zealand any such change would require engineering checks and certification. They'd ask for example if the braking was up to fitting a V12.

Thanks for the advice guys. Looks like pro's and con's.
I'm a bit old skool and the thought of 1 ECU was enough but 3
It'll be a while before I can get the ball rolling with the build and I've decided to ditch the V12 idea.

I'll update when work is in progress

Stand alone aftermarket ecu would probably be easier to sort

When I read these posts about the invasiveness of the IVA, I have to laugh. Here in Connecticut, DMV inspection testing of a Z3 of this era consists of checking to see if the lights work and plugging in the OBD2 plug to see if there are smog-related error codes- that’s it! Other US states are even more lenient.