Zippers Performance


Zipper’s Stage III CNC Ported Evolution® Heads

SKU# 2399

Be the first to review this product

Availability: In stock

As low as: $1,099.00

Price as configured: $0.00

Quick Overview

Owners of Evolution® powered Big Twins can increase their engine’s output with a set of our CNC-ported EV heads! The factory casting is CNC-machined to our proven high torque, high power port shapes and the valve sizes are increased to 1.900” intake and 1.630” exhaust. Ductile iron Step-Lock guides are fitted and topped off with high quality Viton® seals and a performance spring kit. The head gasket surface is decked for flatness before final assembly.

More Views

   

Select Options

+$1,099.00#517-562 Zipper’s Stage III EV-CNC Parts and Labor (customer provided heads)

Price as configured: $0.00

Details

Owners of Evolution® powered Big Twins can increase their engine’s output with a set of our CNC-ported EV heads! The factory casting is CNC-machined to our proven high torque, high power port shapes and the valve sizes are increased to 1.900” intake and 1.630” exhaust. Ductile iron Step-Lock guides are fitted and topped off with high quality Viton® seals and a performance spring kit. The head gasket surface is decked for flatness before final assembly.

    • Full CNC port & combustion chamber machining
    • Ductile iron step-lock valve guides
    • Competition seat work on Serdi equipment
    • 1.900” Int, 1.630” Exhaust stainless steel valves
    • Performance valve springs with Moly collars
    • .630” valve spring free travel
    • 91cc combustion chamber (skim decked)
    • Completely assembled, ready to install

This head has substantially higher low-lift flows for unreal torque increases and is capable of producing over 90 horsepower in an 80” engine (same head used in our 80/80 kit). Requires use of pop-up pistons and possibly additional deck machining for proper compression, depending on your choice of cam and pistons. Spring travel is set for up to .575” valve lift; higher lifts will require an optional spring change.

Evolution® CNC headwork is performed on supplied head cores; in-house shop time is 10-14 working days.

International Customers – Import duties are not required when to shipping your castings for modification. Special low shipping rates are available for your cores; contact your sales representative for details.

Remove heads from engine, wash off oil and ship to Zipper’s as-is. Improper cleaning methods can actually do more harm than good; we suggest you allow us to properly prepare your heads for modification. Extreme care is taken during our preparation process to preserve component finishes. A small cleaning charge applies to heads sent in for modification.
The products on this page are not legal for sale or use on pollution-controlled motorcycles.
Learn More About Emissions Compliance.
Zipper’s Stage III CNC Ported Evolution® Heads http://www.zippersperformance.com/media/catalog/product/cache/1/image/265x/9df78eab33525d08d6e5fb8d27136e95/5/1/517-562.jpg Owners of Evolution® powered Big Twins can increase their engine’s output with a set of our CNC-ported EV heads! The factory casting is CNC-machined to our proven high torque, high power port shapes and the valve sizes are increased to 1.900” intake and 1.630” exhaust. Ductile iron Step-Lock guides are fitted and topped off with high quality Viton® seals and a performance spring kit. The head gasket surface is decked for flatness before final assembly.

    • Full CNC port & combustion chamber machining
    • Ductile iron step-lock valve guides
    • Competition seat work on Serdi equipment
    • 1.900” Int, 1.630” Exhaust stainless steel valves
    • Performance valve springs with Moly collars
    • .630” valve spring free travel
    • 91cc combustion chamber (skim decked)
    • Completely assembled, ready to install

This head has substantially higher low-lift flows for unreal torque increases and is capable of producing over 90 horsepower in an 80” engine (same head used in our 80/80 kit). Requires use of pop-up pistons and possibly additional deck machining for proper compression, depending on your choice of cam and pistons. Spring travel is set for up to .575” valve lift; higher lifts will require an optional spring change.

Evolution® CNC headwork is performed on supplied head cores; in-house shop time is 10-14 working days.

International Customers – Import duties are not required when to shipping your castings for modification. Special low shipping rates are available for your cores; contact your sales representative for details.

Remove heads from engine, wash off oil and ship to Zipper’s as-is. Improper cleaning methods can actually do more harm than good; we suggest you allow us to properly prepare your heads for modification. Extreme care is taken during our preparation process to preserve component finishes. A small cleaning charge applies to heads sent in for modification.
$0.00 Out of stock
0