Triumph Motorcycle Performance Cylinder Head Update Service
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Triumph Motorcycle Performance Cylinder Head Update Service

  |   British Customs


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Triumph Motorcycle Performance Cylinder Head Update Service

Want more power out of your Triumph Twin? The British Customs Performance Cylinder Head Update Service has been designed with the street rider in mind. Street riders needs differ from racers; a street rider needs  an increase in performance across the entire power band, where racers need more top end, wide open performance.


  • Cleaning and inspection: The cylinder head is inspected for wear and tear. The customer will be notified if anything is found. (Shipping is a major source of damage; please package and insure accordingly, broken fins can be fixed, some additional charges may apply.)
  • Porting: The shape of the port is important to the performance of the head. The goal is to increase flow by 10 percent while maintaining a good ratio of intake to exhaust flow. We work the shape of the ports per the application and engine size.
  • Valve job: To increase flow, a 3-angle-valve job is performed on the valve seats and then hand blended to maximize flow.
  • Blending ports: Removes any edges, or irregularities in the ports to maximize flow.
  • Polish the chambers: Polishing the chambers is done to increase low lift flow with a target number of 0 to 300,000.
  • Surface measure and set valve height.
  • Assembly and measuring: The valve stem heights are measured to ensure that the valve lash adjustment is in a comparable range from before the job was started. The valve spring heights are checked to ensure that there is sufficient spring tension and spring rate for the application.

Note: Requires customer to send in stock head to modify. Customer is responsible for all shipping costs. It is not recommended to do the Cylinder Head Update Service without increasing air flow into the motor (see the Air Box Removal Kit) and upgrading your exhaust to a more free flowing exhaust (see complete line of British Customs Exhausts). To further increase performance, it is recommended to port match a set of British Customs Billet Intake Manifolds, this is done free of charge when purchased or sent in with the Cylinder Head Update Service. For those looking for even more power, check out the 2mm oversize valves, street cams and racing carburetors.


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