Milwaukee-Eight®

The 4-valve M8 cylinder head flows considerably more air than previous 2-valve heads – but it needs to, to support today's larger engines. Flow testing the stock heads shows an imbalance between intake and exhaust flow ratios. Our combination of qualifying seat installation, CNC porting, professional seat and guide finishing with oversize valves, careful spring set up and decking ensures you will extract maximum power from your engine modifications while improving the flow imbalance. This work is performed on your supplied head cores.

Not legal for sale or use in California on any pollution controlled motor vehicle. Not legal for sale or use on any EPA pollution controlled motor vehicle.

*To ensure you enjoy a premium experience, Please fill out a Build Sheet/Job Order Sheet prior to completing an order on the website. Click here for Zipper's Build Sheet/Job Order Sheet

This is Zipper’s newest fully developed CNC ported head designed for larger output engines. This head has large increases in flow over the STAGE 3 and tightens the spread between Intake to Exhaust flow ratio with significant improvements to the exhaust port design. Only for use on big bore M8 engines. O.S. Valves are + 2mm 42/34 intake / exhaust valves.  Requires oversized Induction. Final combustion chamber cc range 89-90 cc.

• This service is available for Oil Cooled- Twin Cooled heads
• Porting performed with guides removed
• Included are Upgraded Valve Springs and New Guides
• Oversize valve seat replacement is required with 4.0

Not legal for sale or use in California on any pollution controlled motor vehicle. Not legal for sale or use on any EPA pollution controlled motor vehicle.

*To ensure you enjoy a premium experience, Please fill out a Build Sheet/Job Order Sheet prior to completing an order on the website. Click here for Zipper's Build Sheet/Job Order Sheet