345 replies to this topic

[Udo]

I've been looking at the BMW K series 16 valve head conversion for a while now and finally decided to go for it for my new engine - not that anythings wrong with my current enigne but always on the look out for more power

As there is nothing wrong with my current engine it also allows me plently of time to build the new engine without rushing things

Going to be ordering a new short engine from somebody, just need to decide on who and what bore to go for etc

Gearbox wise I'll probably use my current one but get it rebuilt and comp diff pin / cross pin diff fitted

Head wise I'm probably going to get the casting 'cleaned' up a little in the ports

I need to have a read up / learn about fuel injection as not used it before and will be using the standard throttle bodies and fuel injection - will need an aftermarket ECU which may well be Megasquirt

No time scale set - more likely as funds allow so I'd better get selling some bits

Anyway picked this up last night for a bargin price I reckon



K1100RS complete engine, throttle bodies and wiring loom etc - I believe I read somewhere that the RS model has the higher lift cam's and slightly bigger throttle bodies?

Needs a good clean but its all there and should be able to sell on the bits I'm not using

As I said above no timescale set so it may take a while but I will update as and when I get bits and pieces done.

If anybody has any experience of the conversion then I would be pleased to hear any advice you may have.

Cheers

[miniboo]

ooo nice idea. it does seem to be a really popular choice at the moment

Edited by miniboo, 27 June 2007 - 11:10 PM.

[Sprocket]

Good luck

Ive just today abandoned mine, Again, well, for the moment at least.

Edited by Mini Sprocket, 27 June 2007 - 11:13 PM.

[nmt_oli]

lots of people going down the bmw route atm! Morspeed are building my 16v engine up atm, should be on the dyno next week hopefully. yours is prob goign to be a bit cheaper than mine though! doh!

[ed4ran]

hehehe finally did it.
How strong are the gearboxes on those

EDIT: Dont look like it has a gearbox or are they internal like modern bikes
(seen some on ebay for the k75/k100 and they look external, fit on the end etc)

Edited by ed4ran, 28 June 2007 - 09:08 AM.

[Udo]

Yeah Ed finally made my mind up, few more decisions to be made re bore, short engine supplier etc but I've got the time to sort this while I aquire the funds.

No gearbox fitted to my engine. fits to the right hand end of the engine as it is in the photo then shaft drive to rear wheel

[ed4ran]

If only i had a bike gearbox to play with

[danwebster]

Build your own short engine. Especially on something with the power potential of a twin cam, I wouldn't trust ANYONE, regardless of reputation, with my engine.

[Dog]

Was wondering if this will help you at all...
http://www.users.qwest.net/~shuko/

Also, specialist components are the people to talk to!! When I was going to go 16v, they recommended a K1200RS head and throttle bodies (if you can find one) as these are much better, and have larger ports, and have the largest throttles as standard.

You going injection or Carbs? as MSPD has adapter plates now, so you can fit twin weber DCOE40's but will end up like Dans motor, with a huge nose and not very "stealthy". But like I said earlier, specialist components are the daddies to talk to, if you can. get hold of their "write up" on how to convert a A-Series to a K-Series powered A

[Udo]

Dan - I was planning on building it myself but was going to get a short engine kit from somebody. Or do you mean sort out all the bits ie crank pistons block boring etc individually ?

I understand the power potential of the twin cam and wasn't going to skimp on the bottom end at all.

The biggest thing that I need a bit of advice on is what I need doing to the crank - it seems that theres so many opinions on whats required - what spec is your crank / what do you recommend?

[danwebster]

it depends what power output you are going for, it'll have a bearing on what you can get away with and still have the engine hold together.

[Udo]

Dog - thanks for that but already had that site as a favourites!

I've been speaking to Mark from SC on email

I've bought the engine now, so not on the look out for a K1200. Going to get my head ported anyway

Going to be using the TB's off the engine I have. For one buying carbs to fits would just put the price up when I have the TB's already

Ordered SC build manual yesterday

[Dog]

lol fair enough

[Udo]

it depends what power output you are going for, it'll have a bearing on what you can get away with and still have the engine hold together.

When I was speaking to Mark from SC he reckoned 120-130 with a 1293 16v

I'm probably going to stick to 1293 as it gives the option of rebores later on and as said above going to port the head a little

[Udo]

Right the strip down of the cylinder head off the block revelled some good and bad news

Good news - engine seems to be a low mileage unit, you can still see the honing marks on the cylinder walls, there is no wear or pitting on any of the cam lobes or cam buckets or the chain guides etc

Bad news - one of the bolt holes which the chain cover would bolt into and is still required for the plate behind the top pulleys has cracked (the engine came from a crashed bike did check it over as best I could but missed it) Shouldn't be a problem will get it TIG'd up and redrill and tap the thread when the other machine work is done to the head. Also one of the old exhaust studs is stuck but not a problem for a machine shop

pictures to follow tomorrow