BMW K series cylinder head conversion

[DavidL]

Well, I've tried to search for this on the forum without success. I know it's possible to bolt on (with a lot of work) the head from a BMW K series engine to the A series block, but unsure whether the head I've come across would be worth pursuing as a donor. It's from a 1989 K100RT, and it's an 8 valve head. What I'm unsure about is how much of an advantage this would give me over the Stage 2 (I think) 5 port head I have at present, or whether I should try to track down the 16 valve version (and I'm not sure which BMW had this head, although I'm guessing it would have to be a K1200).

Anyone have any ideas, or better still, experience of fitting the BMW head?

[manifold]

8v version is good. 16v version is better.

http://specialist-components.co.uk/

I haven't direct experience, but I would check out the specialist-components website via John Kimmins. Plenty of info there including a build manual on how to do it.

[Stuart]

Here's a build on the Mini forum http://www.theminiforum.co.uk/forums/to ... 0cc-block/

[DavidL]

Here's a build on the Mini forum http://www.theminiforum.co.uk/forums/to ... 0cc-block/

Thanks A111, I've just read that entire thread. There's a lot of useful information in there, that guy certainly appears to have done his homework!

[Geoff Butcher]

Around £3500! About three times what my car is worth, and that's probably optimistic There must be easier and cheaper ways of going faster...

[DavidL]

Around £3500! About three times what my car is worth, and that's probably optimistic There must be easier and cheaper ways of going faster...

I'd like to think so too.

I wasn't looking for a BMW cylinder head, although I knew that people had done the conversion. I had to deliver a customer's BMW bike to his house and happened to comment on the other stuff in his garage, mainly his other, older bike, a K100RT. His original engine had some terminal cylinder damage. I jokingly asked him if he wanted to sell its cylinder head, at which point he indicated the replacement, complete, engine he had ready to be fitted, and said, "possibly...".

So I'm trying to work out whether I should, or not. I didn't even count the valves, although I think since it's a K100, it's probably an 8 valve. Also, he didn't get any of the injection gubbins with the replacement, so I'd still have to source that and throttle bodies, for a start...

[miniswift]

Hi,

K-100 ITBs are very cheap.
I bought one for £50 off ebay with an air box delivered.
If you need an air box let me know. I don't need them as I'm making ITBs setup for G13B Swift Gti engines are those are the parts I don't need.
I think even the 8v cylinder head is better than 5 ports A-series heads. They are made to flow much higher rpm.
Just strap on 4x bike carbs and you will be fine!

Cheers
Atchi

[DavidL]

Hi,

K-100 ITBs are very cheap.
I bought one for £50 off ebay with an air box delivered.
If you need an air box let me know. I don't need them as I'm making ITBs setup for G13B Swift Gti engines are those are the parts I don't need.
I think even the 8v cylinder head is better than 5 ports A-series heads. They are made to flow much higher rpm.
Just strap on 4x bike carbs and you will be fine!

Cheers
Atchi

Hi Atchi,
Sorry, I must be slow, but what's an ITB? Something throttle body? It's late and my brain is shutting down...

(edit) umm - injection throttle body maybe? Is there one per cylinder or one per engine?

[Stuart]

Close, it's individual, I'm hopeless at them (can't even remember the term this second) ttfn


Edit: after quite some considerable time pondering Acronym

[manifold]

Yes its independent throttle bodies.

I have a couple of sets of ITBs I wont be using, complete with injectors from a GSXR600 which I am sure the right size for your needs. Open to reasonable offers. These can be respaced to suit any engine.

Kind regards,

David