1. Home
  2. Engines
  3. Harbor Freight Engines
  4. Predator 212cc Non-Hemi
  5. Predator 212 Non-Hemi
  6. Performance 5mm Non-Hemi Heads & Components
  7. Wildcat WC946 18cc Big Valve Non-Hemi Cylinder Head – 32/27mm Valves, Titanium Retainers, Dual Springs
Wildcat WC946 18cc Big Valve Non-Hemi Cylinder Head – 32/27mm Valves, Titanium Retainers, Dual Springs
Wildcat Big Valve Cylinder Head
Write a Review

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

Part Number: WC946-4
Online Price: $279.99
Phone Order Price:$299.99
You Save:$20.00(7%)
Availability: In Stock.

Send to:

*We'll ask for shipping info at checkout

Description

Wildcat WC946 18cc Big Valve Non-Hemi Cylinder Head

32/27mm Valves | Titanium Retainers | Dual Springs | .400" Lift Capable


Designed for serious builders and racers, the Wildcat WC946 Cylinder Head is our premium non-hemi big valve head that blends stock-appearing design with serious performance upgrades. Featuring oversized 32mm intake and 27mm exhaust stainless steel valves with 5mm stems, this head is precision-machined for consistency, durability, and out-of-the-box flow performance.


Key Features:

High-Flow Big Valves

- 32mm Intake / 27mm Exhaust Valves with 5mm stems

- Built for increased airflow and stronger top-end performance

- Stainless steel construction for long life under high-RPM use


Precision Valve Work

- Multi-angle valve job performed on Rotter Seat & Guide machine

- Valve bowl area matched and cleaned up to the seats

- Vacuum-tested to ensure reliable sealing and proper combustion


Spring and Retainer Setup for High Lift

- Lightweight Titanium Retainers

- Dual Valve Springs installed and set at:

  -1.000" installed height

  - 43 lbs closed seat pressure

  - 115 lbs open pressure at .575”

  - Coil bind at .535”

- Spring pockets pre-cut to handle cam lifts up to .400"
(Examples: .290 cam with 1.4 ratio rockers = .406 lift)


18cc Combustion Chamber

- Ideal for performance builds where you want a balance of flow and compression

- Great for high-displacement builds like the EC 228R, 236R/RX, and 240RX

- Designed to reduce detonation risk in larger engines while still offering solid compression


Compression Ratio Examples: (Results may vary depending on deck height, gasket thickness, and piston design)

Engine

Gasket Thickness

Compression Ratio

Predator Hemi, Flat Top, .035" Deck

.045"

9.22:1

Predator Hemi, Flat Top, .035" Deck

.010"

10.48:1

Tillotson 212, .000" Deck

.045"

10.48:1

Tillotson 212, .000" Deck

.010"

12.19:1

Tillotson 225, .000" Deck

.045"

10.87:1

Tillotson 225, .000" Deck

.032" EC Copper

11.49:1

EC 228R, .000" Deck

.045"

11.01:1

EC 228R, .000" Deck

.032" EC Copper

11.63:1

EC 236R/RX, .000" Deck

.045"

11.37:1

EC 236R/RX, .000" Deck

.032" EC Copper

12.01:1

EC 240RX, .000" Deck

.045"

11.55:1

EC 240RX, .000" Deck

.032" EC Copper

12.21:1


Note: For very high compression builds, use high-octane or racing fuel to avoid detonation. A copper head gasket may require O-ringing the head for optimal sealing.


Installation Resources:

Check out our full setup and assembly guide:
Big Valve Head Installation Guide


FAQ

Wildcat WC946 Cylinder Head – Frequently Asked Questions (FAQ)


Q1: What engines is this cylinder head compatible with?

A: The WC946 head is designed for Predator 212 Non-Hemi, Tillotson 212/225, and other clone-style engines with compatible bolt patterns and flat-top pistons. It's a perfect upgrade for EC 228R, 236R/RX, 240RX, and other big-bore builds.


Q2: What are the valve sizes and stem dimensions?

A: This head features 32mm intake and 27mm exhaust stainless steel valves, each with 5mm stems for increased durability and flow capacity.


Q3: Does this head come ported or CNC-machined?

A: No. The head maintains a stock casting appearance and has not been ported, which allows for customization by experienced builders. However, the valve bowl area has been cleaned up and matched to the seats, and a multi-angle valve job has been performed for improved flow and sealing.


Q4: What is the installed spring setup, and what cam lift does it support?

A: The WC946 comes assembled with:

  • Dual valve springs
  • Titanium retainers
  • Installed height: 1.000"
  • Seat pressure: 43 lbs
  • Open pressure at .575": 115 lbs
  • Coil bind: .535"

The spring pockets are cut to handle up to .400” of cam lift, making it ideal for mid-to-high lift cams depending on rocker arm ratio.


Q5: What is the combustion chamber size, and how does it affect compression?

A: The WC946 has an 18cc combustion chamber, which provides a strong compression base without being too small for high-displacement engines. It helps avoid detonation in large engines where a smaller chamber would push compression dangerously high.


Q6: Will this cylinder head raise my compression ratio?

A: Yes, it can. Depending on the engine, deck height, and head gasket thickness, compression ratios will vary. For example:

  • Tillotson 212 w/.010" gasket = ~12.19:1
  • EC 240RX w/.032" EC copper gasket = ~12.21:1

Refer to our compression ratio chart in the product description to estimate your setup.


Q7: Should I O-ring the cylinder head?

A: If you're using a copper head gasket (especially under high compression or with methanol), we recommend O-ringing the head for improved sealing and durability.


Q8: Do you provide setup instructions or installation guides?

A: Yes! A complete guide for installing and setting up our big valve cylinder heads is available here:
?? Big Valve Head Instructions & Setup Guide

Related Items

Recently Viewed Items