EC CNC Ported Big Valve 32/25mm Head using the Tillotson JT-207 Cylinder Head.
Based on popular demand, we have built a 32/25mm valve combination cylinder head. Engine Builders and racers have found that the peak torque is at lower rpm with a smaller exhaust valve that improves low-end torque, leading to better acceleration for engines built for low-speed corners on short ovals or sprint kart racing or drag racing setups.
The Head Comes with 32mm Intake and 25mm Exhaust Valves; 5mm Stems. Precision Multi-Angle Job, Valve Bowl area, cleaned up match to the seats. The valve work is performed on Rotter Seat & Guide Machine for accuracy and precision. Heads are vacuum checked after the valves are installed to ensure your air-fuel mixture and combustion happens in the cylinder. The Heads Milled to ~18cc Combustion Chamber. The Cylinder Head is CNC Ported on our state heart multi-axis HAAS Machines. CNC porting rather than hand porting makes each port job consistent and accurate from head to head. This also reduces the cost of labor to make it more budget-friendly. Springs, Retainers, Rockers, Gaskets, Seals, or valve covers are omitted.
Intake: 32mm, 5mm
Exhaust: 25mm, 5mm
Combustion Chamber: 18cc, Non-Hemi
Multi-Angle Valve Job
Compression Ratio Examples(Final Result will vary on Engine Measurements):
Predator Hemi, Flat Top, .035" Deck height,
w/.045" Thick Head Gasket 9.22:1
w/.010" Thin Head Gasket 10.48
Tillotson 212, Flat Top, .000" Deck height,
w/.045" Thick Head Gasket 10.48:1
w/.010" Thin Head Gasket 12.19:1
Tillotson 225, Flat Top, .000" Deck height,
w/.045" Thick Head Gasket 10.87:1
w/.032" EC Copper Head Gasket 11.49:1
EC 228R, Flat Top, .000" Deck height,
w/.045" Thick Head Gasket 11:01:1
w/.032" EC Copper Head Gasket 11.63:1
EC 236R, Flat Top, .000" Deck height,
w/.045" Thick Head Gasket 11:37:1
w/.032" EC Copper Head Gasket 12.01:1