Bimmer twinky heads the same?
Turbo Mini Forums

Hi, just a quick question.

Do both the K1100 an K1200 cyl heads have the same stud pattern add require the same mods to fit to the a-series lump? I've read the K1200 has larger valves, is this all thats different?

thanks.

I am no expert, but I believe the casting is the same. The valves are the same size, but they have thinner (5mm) valve stems. The oil feed to the cams is in a different place as is the water temperature sender. The RS cams have higher lift and longer duration and have 38mm throttle bodies.

The conversion is the same for both I'm led to believe.

You need to check with John Kimmins from Specialist Components to be sure.

Nick.

The front plate mounts are different, but easilly altered.
Everything else is as above!

The only real difference is the oil feed to the head - the K12's have it through the front gallery between the cams - not up the head like the A series and k100/k1100 heads - this means either boring up into the head to generate a feed through the block or external feed through the drilling at the rear of the head -easiest option(this is there on K100/k1100 heads as well)
Valve head sizes are the same. the conversion kit fits all the K family heads.

cheers

John

If Carling made Mini engines
it would probably be like this one!