BMW K100 head on a mini 1275 block

I am doing this for a co-worker. I have been fascinated by this swap since I first heard about it in the late 90's. Tim got the kit in a large lot of mini stuff he bought years ago and it languished in a friends machine shop for 18 months waiting for him to "get around to it"

I think I can do it faster.

Man this is gonna be cool!

I read the book and am ready to dive in.

This cart is loaded down with all the bits.

An ECU system for the injection, A pretty little stainless header, A beautiful forged crank with a $3400 invoice still in the box with it. Should be everything I need.

First step was to identify all the holes that need to be filled and drill them out.

I had originally planned on using a plugs of 5 different sizes ranging from 5/16" to 9/16" but in process I decided that was probably overkill and went with 9/16"-18, 1/2"-20 and 3/8"-24. Some of the holes were already the perfect tap drill size.

So as of today the block has had all of the holes to be filled drilled and tapped. Tomorrow I will heat up the parts washer and give it a good degreasing and loctite the threaded slugs in place.

So that is the end of day one.

What is left? after the holes are filled and the surface is flycut I will drill the new pattern and tap the necessary holes for the new head studs. At that point the block goes off to Springer Performance to be bored out for the new pistons and zero decked. While that is happening I have to weld an extension onto the the BMW head and then machine the cam belt side flat. There are a few holes on the bottom of the head to fill and then it has to be drilled and tapped for the oil return lines. Shouldn't be too tough.

I thought this project was way too cool not to share. 

In reply to Jumper K Balls :

:-0

Wow, I have heard talk of doing such a swap (in theory) but never heard of it actually happening. I am anxious for updates and dyno numbers

Woot! Woot!

Excited to see this documented. I don't have a classic mini but I think this conversion is extremely cool.

I have been a classic mini fan since high school when I saw a classmate's dad drop him off in a rhd one. This swap has intrigued since I first heard about it, and it great to get a chance to follow along as it progresses.

Very cool!!

I remember bookmarking the site http://www.lojomo.com back in Netscape navigator 2.0. Nice to see it still up and totally unchanged.

I want to showcase this build on our work site so perhaps we can get more work like this. I would love to do this to a sprite or a minor or really any A series powered car.

I need to derust my CAD skills and draw up the plates so I can make my own bits. This Specialist Components kit seems of high quality though.

I heard of something like this for a Fiat 850 motor using a  "Japanese" head......

I guess all you need is the bore spacing to be close to have something to start with :)

OHHH and it seems a BMW 1200rs 16v head has been adapted to a Mini motor too !

I love projects like this. I'm looking forward to seeing the rest of it.

I love that there are mad scientists in this world, I think they’re why the world still spins

I like these swaps waaay more than honda d or b series swaps. 

Never driven or ridden in one yet though. 

In reply to SLGGR :

Your mini might have the potential to change the spin if the earth. 

Cool. I knew about this swap, but I'd never seen what has to be done. The snorty A series is a big part of the character of the Mini, and this is the mad edge of that world.

Edit: A friend just pointed out that this engine will have three cams when it's done. Which is awesome.

I've seen pictures of these, but it'll be great to see the build process.  

Thanks for sharing! 

almost looks like a backwards b16

I guess I am going to be "that guy".  A $3400 forged crank in a 3 main bearing engine?   I guess I am just not a Series A fanboy.   Since the similar Datsun engine is so close and had five main bearings, would the cylinder head work on it as well? 

Well it would stand to reason that a deficiency like a weak 3 main crank would be a good thing to address, perhaps by replacing it with a higher quality one 

The Nissan version shares no parts with the BMC A series. The cam is even on the other side of the engine.  I bet the head swap is possible with a complete re-engineering of the kit, but I am sure the Nissan parts bins offer better choices.

The crank is only about 2' long and it's not like it's going to see excessive rpm or high power, three mains may just do the trick. There aren't a lot of secrets left in the A series anymore, they're pretty well understood.

Jumper K Balls said:

I would love to do this to a sprite or a minor or really any A series powered car.

 

I need to derust my CAD skills and draw up the plates so I can make my own bits. This Specialist Components kit seems of high quality though.

Yeah, I would love to see this done on a spridget! If you need CAD help I do that for a living. Fushion 360 is a good free option out there.

I'm not a mini guy but I love seeing these off the wall rocket surgeon conversions.  Never tell a guy that knows how to run a mill something won't fit.  Excited to see more of this.

I would have loved to be in the room when the first guy started wondering if this was possible.

3 cams!? I am scintillated.

My first car was a 948 Sprite ('63)

My brother had a '64 1100 Midget that I may, or may not have inherited.

My current project is a '60 Bugeye.

Jumper makes awesome E36 M3! Looking forward to seeing where this goes. 

I love these weird franken motors. This and Folvos are some of my favorites. 

simon_C said:

I love these weird franken motors. This and Folvos are some of my favorites.

I was coming to post the same thing. I saw a guy in NJ making them almost 20 years ago now, and was blown away!