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Cosworth CNC Ported Big Valve Cylinder Heads
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For over 40 years, Cosworth has been
the leader in innovative multi-valve cylinder head design for both racing and high performance production cars. The Cosworth CNC Ported Big Valve Cylinder head range is the latest advancement. Modified from new OE cylinder head castings, substantial gas flow improvements and upgraded valve train components offer superior performance for your high performance engine. Each original cylinder head design is carefully evaluated and tested to establish the improvements required to meet the target performance level. Hours of testing and flow bench validation are used to determine the best advanced port design yielding maximum usable power and response. However, there is more to cylinder head design than just maximum flow. It is critical that port velocity is maintained to ensure drivability and valvetrain components are matched to guarantee reliable performance. Once all of these factors have been tested and validated, the final port contour is digitized. Using the digitized program, both intake and exhaust ports are reshaped using a 5-axis CNC mill producing an accurate and consistent port shape every time. In addition to re-shaping and enlarging the intake and exhaust ports, most Big Valve Cylinder heads feature a re-shaped combustion chamber to unshroud the valves increasing air flow and performance. After machining, each cylinder head receives a multi-angle high performance valve job on Cosworth's precision CNC valve seat cutter. Then each cylinder head is ultrasonically cleaned, serialized and finally hand assembled with select high performance valve train components, ready to install on your engine. |
Product Features:
- All New OE Castings
- Enlarged intake and exhaust ports
- Machined port bore finish
- Knife edge port divider
- 4-angle Inlet Valve job
- 3-angle & radius Exhaust Valve job
- Valves are lapped
- Back-Cut Inlet Valves
- +1mm Stainless Steel Intake Valves (1800 degrees max.)
- +1mm Inconel Exhaust Valves (2400 degrees max.)
- Hi-rev, dual valve springs
- Titanium Retainers
- Hardened Steel Spring Platforms
- Reshaped combustion chamber on
most applications
- Ultra Sonic cleaned prior to assembly
- Flow bench proven design
- Dynamometer tested
- Serialized and sport a machined Cosworth logo
- Pre-assembled, ready to install
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Applications available for CNC Machined Big Valve Cylinder Heads
FORD |
| Part Number |
Engine |
Engine Type |
Years |
Applications |
Notes |
| 20000691 |
Duratec |
2.0L, 2.3L DOHC |
07-09 |
Ecosport, Focus, Fiesta |
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MAZDA |
| Part Number |
Engine |
Engine Type |
Years |
Applications |
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| 20000704 |
MZR |
2.0L, 2.3L DOHC |
06-09 |
Miata, Mazda3, Mazdaspeed 3 |
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MITSUBISHI |
| Part Number |
Engine |
Engine Type |
Years |
Applications |
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| KK3672 |
4G63 |
2.0L DOHC |
01-05 |
Evo VII, VIII |
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| KK3852 |
4G63 |
2.0L DOHC MIVEC |
06-07 |
Evo IX |
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| 20005685 |
4B11 |
2.0L DOHC MIVEC |
08-09 |
Evo X |
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NISSAN |
| Part Number |
Engine |
Engine Type |
Years |
Applications |
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| KK3918 |
VQ35DE |
3.5L DOHC VVTi |
03-06 |
350Z, G35 |
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SUBARU |
| Part Number |
Engine |
Engine Type |
Years |
Applications |
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| KK3670 |
EJ25 |
2.5L DOHC AVCS |
04-06 |
Impreza WRX, STI |
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| SB8010 |
EJ25 |
2.5L DOHC AVCS |
04-06 |
Impreza WRX, STI |
w/ KK3766 camshafts, USDM models |
| SB8012 |
EJ25 |
2.5L DOHC AVCS |
04-06 |
Impreza WRX, STI |
w/ KK3920 camshafts, JDM/EUDM models |
| 20001699 |
EJ25 |
2.5L DOHC AVCS |
2007 |
Impreza WRX, STI |
w/ Air Injection Ports |
| 20002024 |
EJ25 |
2.5L DOHC AVCS |
2007 |
Impreza WRX, STI |
w/ Air Injection Ports. KK3766 camshafts; USDM models |
| 20002026 |
EJ25 |
2.5L DOHC AVCS |
2007 |
Impreza WRX, STI |
w/ Air Injection Ports, KK3920 camshafts; JDM/EUDM models |
| 20004544 |
EJ257B |
2.5L DOHC AVCS |
08-09 |
Impreza STI |
w/ Dual AVCS |
| 20010040 |
EJ257B |
2.5L DOHC AVCS |
08-09 |
Impreza STI |
w/ Dual AVCS, 20007395 camshafts |
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