bmw k1200lt bmw k1200rs compression ratio
Turbo Mini Forums

hello all, i'am johan hogenbirk from the netherlands.

i have a bmw k1200lt and have a question about the compession ratio.
the 1200lt is 10.8:1 and the 1200rs 11.5:1 but the pistons and cil head have the same part numbers.
how do they realize the diverence.
i will have more power at my bike (400kg)and will look for two rs camshafts.

thanks regards johan

Edited by johan on 16th Oct, 2018.

1171cc with a head volume of 19cc, piston dish of 7cc, 4cc Gasket and zero dec height gives 10.8:1

If The stroke and Bore is that Same and the head is the same and the pistons are the same then the only thing that can change to get 11.5:1 is the gasket. Check out the gaskets and see if the RS one is thinner

1171cc with a head volume of 19cc, piston dish of 7cc, 2cc Gasket and zero dec height gives 11.5:1

It may be total bollocks but that's the only way I couls get 10.8:1 to 11.5:1 using the details you provided

Wayne

Kind of related:
http://www.turbominis.co.uk/forums/index.php?p=vt&tid=397823

Bmw head gasket is 1.6mm thick and at least 6cc volume. It is possible there are two thickness head gasket for LT and RS but I’ve not come across that.

oke thanks for respons, i will check out the p/n and thickness of the gasket

i checked it but also the gasket is the same p/n ??????
https://www.realoem.com/bmw/enUS/select?product=M&archive=0

longer con rod ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Where did you find the info on compression ratio? I've seen miss prints in the BMW workshop manuals before now.

I was intrigued by it and have been googling it quite a lot, those ratios are mentioned quite a lot in different places. I haven't found anything yet regarding the calculations

i googled specs k1200lt and k1200rs

what do you think is the difference in horsepower only by the camshafts or also a combi with the ecu