Description
CSR 128″ High Compression Big Bore Kit
The best cylinder kit for your M8! The CSR 128″ High Compression Big Bore Kit will take your 114/117″ engine to a 128″. It is designed for the individual who wants to upgrade his motor and use their existing cam. Head work is not required but optional later. This kit consists of cylinders, pistons, rings, head and base gaskets, and a top end rocker box gasket kit. It is a great match for the following cams:
Optional Add-Ons:
- Feuling 3007 ARP Head Bolt Kit or S&S 900-1006 Head Bolt Kit
- T-Man Cylinder Head Breather Valves or Feuling Cylinder Head Breather Valves
- CSR 62mm Throttle Body
- Zipper’s 7.1 gps High Flow Injectors
The CSR 128″ High Compression Big Bore Kit is American-Made and manufactured by the same company that makes our 139″, 144″, 147″ and 153″ motor kits. We take the best cylinder cores and bore them out, remove the original steel liner, and add a tensile strength Ductile Iron material for our proprietary sleeves. This allows the sleeves to stay straight and round for the perfect ring seal with our Total Seal rings. Our pistons are made to our specifications from Forged aluminum material. Wrist pins are made from tool steel to give maximum strength and durability. We use Cometic gaskets for all of our Big Bore kits. Bore size is 4.25 with a domed piston to raise the compression to 12.3:1 for both the 124″ and 128″. These are not flat top cylinder pistons!
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The CSR 128″ High Compression Big Bore Kit should be used with an upgraded cam, throttle body, and exhaust system. It makes the most power from all the available parts on the motorcycle because of the higher compression ratio. We have seen up to 150 foot lbs of torque from this kit on bikes running a 2:1 exhaust, 468 cam, and a larger throttle body. It is all about the torque! The exhaust hugely dictates where power is made and how much. If you have a side dump 2:1 or a 2:1:2 header then you will not make as much horsepower or torque as a full 2:1 system such as the D&D Billet Cat or Bassani. Power is all about the perfect combination of parts.
- This project requires a skilled technician. It is the responsibility of the person assembling the parts to check all clearances and assembly specifications.
- We highly recommend using Feuling’s ARP Cylinder Stud kit during install to avoid reusing stretched stock cylinder studs.
Important Information (MUST READ):
*A ThunderMax Auto Tune System is highly recommended for this product if you do not already have an aftermarket tuner. If you have one already, we can also provide you a recommended base map if you purchase this kit.*
