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Tillotson 212R-225RS 27/25 5mm Bare Cylinder Head
138210100 Tillotson 212R/225RS Cylinder Head Bare
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Tillotson 212R-225RS 27/25 5mm Bare Cylinder Head

Part Number: 138210100
Online Price: $44.99
Tillotson TIL-1/JT-207 Performance Cylinder Head – 27/25mm Valves | Fits GX200, Predator, Clone
Availability: In Stock.

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Description

Tillotson TIL-1/JT-207 Cylinder Head – 27/25mm Valve Version for GX200 & Clone Engines


The Tillotson TIL-1/JT-207 Cylinder Head has been redesigned for enhanced airflow and performance. Originally developed for the 196R Box Stock engine, this updated version now features larger 27mm intake and 25mm exhaust valve seats with 5mm valve guides, replacing the previous 25/24mm valves with 5.5mm stems.


These improvements make it one of the best factory cylinder heads available for high-performance small block engines, especially for users upgrading from older 25/24mm setups.


Key Performance Upgrades:

  • Valve Seat Upgrade: Enlarged to accept 27mm intake and 25mm exhaust valves
  • Valve Guide Reduction: From 5.5mm to 5mm for reduced valve mass and improved flow
  • Combustion Chamber Volume: ~20.9cc for improved compression setup flexibility
  • Improved Port Flow: Maximizes the power potential of Tillotson 212R and 225RS engines

This is the OEM cylinder head used on Tillotson 212R and 225RS engines.


Fitment Compatibility:

  • Honda GX200 / 196cc Clones
  • Tillotson 196cc – 268cc (212R, 225RS, 228R, 236R, etc.)
  • Predator 212 (Hemi*)
  • Predator 224 Non-Hemi
  • Ducar 196 / 212 / 224
  • Wildcat 223 / 240
  • Ghost 212

*Note: Engines originally equipped with Hemi-style heads will require non-Hemi valvetrain components and adjusted pushrod length to ensure proper geometry.


Specifications:

  • Intake Valve Seat Diameter: 27mm
  • Exhaust Valve Seat Diameter: 25mm
  • Valve Guide Size: 5mm
  • Combustion Chamber Volume: ~20.9cc
  • Material: Cast Aluminum
  • OEM Part Number: 138210100

Valves, springs, retainers, and seals are NOT included. Use with 5mm stem valves and corresponding valvetrain hardware.

FAQ

Q1: What makes the TIL-1/JT-207 head different from a stock GX200 or Clone head?
A: This head is upgraded with larger valve seats (27mm intake, 25mm exhaust) and lighter 5mm valve guides, improving airflow and increasing performance potential. It also has a ~20.9cc combustion chamber, making it a great match for high-performance builds.


Q2: Can I use this head on a Predator 212 Non-Hemi?
A: Yes, but you will need to run the modified head for 12mm dowel pins


Q3: Are valves or springs included?
A: No. This is a bare cylinder head. You will need to purchase 5mm-stem valves, springs, retainers, and seals separately.


Q4: Will this increase my engine’s compression?
A: Yes, the ~20.9cc combustion chamber and ability to run thin gaskets or flat-top pistons can increase static compression, but actual gain depends on your engine’s deck height and piston/head combo.


Q5: What engines does this cylinder head fit?
A: It fits most small block Honda-style clone engines including:

  • GX200 / 196cc Clones
  • Predator 212 (Hemi & Non-Hemi with mod)
  • Predator 224 Non-Hemi
  • Tillotson 196R–268R series
  • Wildcat 223 / 240
  • Ducar 196 / 212 / 224
  • Ghost 212


Q6: What valves do I need for this head?
A: You will need:

  • 27mm intake valve
  • 25mm exhaust valve
  • 5mm valve stems
    Make sure to select valves designed for GX200-style heads with 5mm stems.

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