Porting for stock or oversize valve BMW N20B20 head.
Includes work only, using customers head, valves and parts.
Oversize valves, guides, retainers, springs etc. can be supplied separately.
Price includes:
- Disassembly, cleaning and assembling
- Porting and flow measurements before / after
- Valve refacing
- Valve seat machining to head
- Re-surfacing
- New valve seals
Flow increase over stock head is ~40% with stock valves on Intake side and ~10% on exhaust side.
Exhaust to Intake flow ratio is high and runners are kept small and
efficient for good tumble, burn efficiency and improved VE%.
Delivery time ~2-months
