- EVOLUTION Performance Heads – 3-1/2″ Bore Billet Aluminum (6061-T6) Heads for the Harley-Davidson™ EVOLUTION models.
- Top-breathing (OEM venting ports location)
- Bolt-on installation for all ’85-’99 80CUI models, designed to match OEM flat-top pistons (not supplied) – including all available overbore sizes.
- This headset achieves very strong torque / power curves (in excess of 90HP, with proper setup/tuning) that peaks exactly where needed, providing you with the fantastic passing power, yet not straining when cruising at your leisure.
- Our product is user-friendly and easy to service down the road also. No custom pistons, valves, guides, fasteners, etc. to worry about.
- Fast, very efficient ports designed to make peak power/torque within the useful RPM range. Your bike will pull hard from the get-go all the way up to the redline. The longevity and fuel mileage won’t suffer either.
- Proprietary, super-fast design of the 75CC combustion chamber yields 9.4:1 calculated compression ratio with flat pistons (@ 80CUI).
- Valvetrain (AV&V and/or KPMI) components accept up to .635” valve lift, with almost .200” lift before valve-to-valve contact. Using tall camshafts may require an additional machining to provide necessary clearances.
- Increased cooling area drops the head’s operating temperature up to 35F.
- ***The Intake and Exhaust ports surface finish is intentional.
- Warranty details and conditions are listed in the Installation Manuals ( Manuals download page )
1 review for EVOLUTION Performance Heads – OEM Bore
The EVO heads are even more beautiful than I could have imagined! Thanks