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Wildcat WC946 CNC-Ported 18cc Big Valve Cylinder Head – 32/27mm Stainless Valves, Titanium Retainers, Dual Springs
CNC Ported Wildcat Big Valve Cylinder Head
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Wildcat WC946 CNC-Ported 18cc Big Valve Cylinder Head – 32/27mm Stainless Valves, Titanium Retainers, Dual Springs

Part Number: WC-946-5
Online Price: $359.99
Phone Order Price:$399.99
You Save:$40.00(10%)
Wildcat WC946 CNC-Ported 18cc Big Valve Cylinder Head – 32/27mm Stainless Valves, Titanium Retainers, Dual Springs
Availability: In Stock.

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Description

Wildcat WC946 CNC-Ported 18cc Big Valve Cylinder Head – 32/27mm Stainless Valves, Titanium Retainers, Dual Springs Precision CNC Ported Performance for Race-Ready Power


The Wildcat WC946 CNC-Ported Big Valve Cylinder Head is the next evolution of our proven stock-appearing performance head—engineered for power, precision, and consistency. Designed for Predator 212 Non-Hemi, Tillotson 212/225, and other clone engines, this head combines 32/27mm stainless valves, titanium retainers, and CNC-machined ports for serious airflow gains in your racing or high-performance build.


Key Features & Specs:

CNC-Ported for Consistent Flow

Ported on our advanced multi-axis HAAS CNC machines, the WC946 offers unmatched port-to-port consistency that hand-porting simply can’t match. This ensures every head delivers the same high-flow performance right out of the box—at a lower cost and with no guesswork.

Big Valve Configuration

  • 32mm Intake / 27mm Exhaust Stainless Steel Valves
  • 5mm Valve Stems for improved strength and reduced mass
  • Multi-angle valve job and bowl blending performed on a Rotter Seat & Guide Machine
  • Vacuum-tested to ensure proper valve seal and combustion integrity

Titanium Retainers & Dual Valve Springs

  • Set at 1.000" installed height
  • 43 lbs closed seat pressure, 115 lbs open at .575", .535” coil bind
  • Spring pockets cut for up to .400" of valve lift, making this head compatible with a wide range of cams and rocker ratios
    (Examples: .290 cam x 1.4 = .406", .335 x 1.2 = .396")

    18cc Combustion Chamber
  • Carefully designed chamber provides a balance of flow and compression
  • Sized to support higher-displacement engines without excessive compression
  • Helps avoid detonation in big-bore builds running pump gas

For high-compression builds, be aware that the 18cc chamber can push compression ratios beyond pump gas limits—especially in engines like the 236RX and 240RX. In these cases, high-octane fuel or methanol is recommended.


Compression Ratio Estimates (Will Vary by Build):

Engine Setup

Head Gasket

Compression Ratio

Predator Hemi (Flat Top, .035” deck)

.045”

9.22:1

Predator Hemi

.010”

10.48:1

Tillotson 212 (.000” deck)

.045”

10.48:1

Tillotson 212

.010”

12.19:1

Tillotson 225

.045”

10.87:1

Tillotson 225

.032” Copper

11.49:1

EC 228R

.045”

11.01:1

EC 228R

.032” Copper

11.63:1

EC 236R/RX

.045”

11.37:1

EC 236R/RX

.032” Copper

12.01:1

EC 240RX

.045”

11.55:1

EC 240RX

.032” Copper

12.21:1


Installation & Setup Guide:

Full instructions available:
Big Valve Head Setup Guide


Applications:

  • Predator 212 Non-Hemi
  • Tillotson 212R / 225R / 228R / 236R / 240RX
  • Wildcat 240RS
  • Other clone and kart engines requiring high-flow, stock-appearance heads

FAQ

FAQ – Wildcat WC946 CNC-Ported Cylinder Head

Q1: What engines is the WC946 CNC-Ported Cylinder Head compatible with?

A: This head is designed for Predator 212 Non-Hemi, Tillotson 212/225/228R, and Wildcat 240RS engines. It fits clone-style platforms that accept 18cc non-hemi cylinder heads with stock bolt patterns.


Q2: Is the head CNC ported or hand ported?

A: The WC946 is fully CNC ported using multi-axis HAAS machines for precise, consistent flow across every head. This eliminates the inconsistencies of hand porting and reduces cost.


Q3: What are the valve sizes and stem dimensions?

A: The head comes equipped with 32mm intake and 27mm exhaust stainless steel valves with 5mm stems, optimized for airflow and strength.


Q4: What camshaft lift can this cylinder head support?

A: Spring pockets are machined to handle up to .400” valve lift. It works with most mid- to high-lift cams and various rocker ratios (1.1 to 1.4).


Q5: What kind of springs and retainers come installed?

A: Each head includes:

  • Dual valve springs
  • Titanium retainers
  • Set at 1.000" installed height
  • 43 lbs seat pressure / 115 lbs open @ .575"
  • Coil bind at .535"


Q6: What is the combustion chamber size, and how does it affect compression?

A: The chamber is 18cc, ideal for balancing power and detonation resistance. It produces higher compression in big-bore builds like 236R or 240RX and may require race fuel or methanol at extreme ratios.


Q7: Do you provide compression ratio estimates?

A: Yes. Examples with flat-top pistons include:

  • Tillotson 225 w/ .045" gasket – ~10.87:1
  • EC 236R w/ .032" copper gasket – ~12.01:1
  • Predator Hemi w/ .010" gasket – ~10.48:1

Exact results depend on deck height, gasket thickness, and piston design.


Q8: Is there an installation or setup guide?

A: Yes! A detailed installation guide is available here:
Big Valve Head Setup Guide

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