M8 Bottom End Service

T-Man’s M8 Bottom End Service is the premier choice for your high-performance big cubic inch motors or STD rebuild Harleys. We partner with Darkhorse Motor Co. and use their cranks exclusively to bring you the best crank service possible, whether you want to rework your existing crank or are looking to upgrade to a new one. These cranks are done to our specifications and have a lightning program that separates ours from others. Our bottom end process starts with align boring your cases, followed by installing our custom Timken bearing insert, which provide more support for your crank. Our Timken system features a custom-made steel insert that offers significantly enhanced durability and support for the bearing compared to the stock setup or other options available on the market.

One of the cornerstone features of this service for the stock cases is our proprietary scraper system. We believe this is the fix for wet sumping issues and will create a reliable, consistent oiling system. We install our proprietary reed valve for better pressure relief under the piston on the downward motion and pinion bearing stop screws for added safety. If needed for your application, we also offer the option to bore your cases for larger bore cylinders. Additionally, we will set your endplay and fully assemble the bottom end with a full spec sheet of all work performed before shipping. With the M8 motors producing more power and torque, our M8 Bottom End Service is an excellent way to guarantee confidence in your investment.

If you are interested in Bottom End Service but looking for more durability than what your stock cases can provide, we are excited to announce that T-Man Performance now offers the same outstanding services for S&S cases. These cases are a very sturdy upgrade for any cubic inch and performance build; however, we strongly recommend them when using  4.500” or larger bore cylinders due to the thicker castings.

Below, you will find different spec sheets for whichever option you are looking for. From stock cases with a refurbished crank to S&S cases featuring a new crank. Each spec sheet also includes upgrade and repair options for you to consider.

If you are interested in our M8 Bottom End Service, please complete our M8 Bottom End Service Build Sheet and someone from our team will be in touch to discuss what you are looking for and can send over a personalized quote for your specific situation. If you are considering top-end work as well, click here to see our M8 full performance kits.