Big Bore Kit 1070cc "S" Touring

Plug & Play Kit.

Siebenrock Big Bore Kit – The Original: Powerful, uncompromising, and time-tested.
Back in 2004, Siebenrock presented its groundbreaking 1070 cc Big Bore Kit to the public for the first time at the Intermot trade show. The innovative design – featuring a short, weight-optimized piston paired with a forged H-beam connecting rod measuring approximately 151 mm in length – was a technical highlight. The extended rod geometry ensures that the piston remains entirely within the cylinder bore, eliminating intrusion into the crankcase. This clever engineering concept received immediate acclaim and has since inspired numerous imitators.
More than two decades later, the Siebenrock BBK 1070, now equipped with the renowned asymmetric camshaft, continues to rank among the most powerful, reliable, and refined plug & play upgrade solutions for classic BMW 2-valve boxer engines. Delivering over 100 Nm of torque, it represents the perfect union of technical sophistication, German-made quality, and a genuine passion for engineering.

No matter which one you choose - you`ll have lots of fun. Guranteed!

1070 ccm dispacement, 80 PS approx. and giant torues between 90 and 116 Nm argue for themselves.

In addiion to our standard kit, that is established over the years we now have the "Touring" variant equipped with slightly shorter con-rods, for those who look for a powerful smooth riding performance and a plus of torque in the loer revvs.


This ultimate Big Bore Kit for tourers and long-distance travrellers deliveres powerful torque "off the cuff". It persuades in every situation with a quiet engine running and tolerates a bad quality fuel down to 95 octane approx. without knocking.

Top quality.
Small production runs.
Engineered in Germany.
Made in Italy.

Siebenrock product.
Each original Siebenrock product bears this seal that guarantees the highest quality possible, consistently optimized down to the last detail.

The scope of delivery includes all parts relevant for the assembly of the set:

2 cylinders with pistons
Piston rings
Connecting rod with ARP screws
Asymmetric camshaft
Gasket set camshaft
Gasket set cylinder
Socket for connecting rod screws.

Conrod bearing shel, art.no. 1124460,l must be ordered seperately!

With MOT/TÜV approval and installation instruction.
Price for the set.

For the classic BMW 2-valve Boxer models
R 100, R 100CS, R 100RS, R 100RT
Monolever models R 100RS (x), R 100RT (x)
Paralever models R 100GS (x), R 100R (x).

(x) = only permitted for vehicles up to 31.3.1994.

TIP
The use of dual ignition is strongly recommended.

Information on product safety
Ready-to-install camshaft including camshaft gear and front camshaft bearing on request.