Supertech MAEVN-1206-8 – +1 mm Oversize Black-Nitrided Exhaust Valve Set (Mazda BP 1.8 L)
Supertech’s MAEVN-1206-8 kit supplies eight +1 mm oversize exhaust valves for the 1.8 L Mazda BP engine found in the MX-5/Miata (1994-2005) and Ford Escort GT. Each valve is forged from 23-8 N stainless steel and finished with a Black Nitride coating, improving heat resistance, reducing stem-to-guide friction, and boosting exhaust-flow capacity.
Key Features
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+1 mm head diameter (29 mm) – larger curtain area increases exhaust flow, supporting higher power at elevated RPM.
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Black Nitride surface (~52 HRC) reduces wear and lowers friction for better guide life and valve stability.
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One-piece forged stainless construction delivers superior fatigue strength and crack resistance under extreme temperatures.
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Single-groove keeper is compatible with most Supertech and OEM spring/retainer sets.
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Direct fit after minor seat enlargement—ideal for ported heads or builds targeting higher exhaust throughput.
Technical Specifications
| Parameter | Value |
|---|---|
| Valve type | Exhaust |
| Head diameter | 29.00 mm (+1 mm) |
| Stem diameter | 5.94 mm |
| Overall length | 102.0 mm (STD) |
| Material | 23-8 N stainless steel |
| Surface treatment | Black Nitride |
| Keeper style | Single groove |
| Pieces per kit | 8 |
Vehicle Compatibility
| Brand | Model | Generation / Chassis | Engine |
|---|---|---|---|
| Ford | Escort GT | 1994-2005 | BP 1.8 L |
| Ford | Miata | 1994-2005 | BP 1.8 L |
| Ford | MX-5 | 1994-2005 | BP 1.8 L |
| Mazda | Escort GT | 1994-2005 | BP 1.8 L |
| Mazda | Miata | 1994-2005 | BP 1.8 L |
| Mazda | MX-5 | 1994-2005 | BP 1.8 L |
SUPERTECH
Supertech Mazda Miata 1.8L Black Nitrided Exhaust Valve - +1mm Oversize - Set of 8
Tags: Engine\By Car Make\Mazda\1.8 I4 (VC),
| Brand | Model | Generation | Engine |
|---|---|---|---|
| Ford | Escort GT | 1994-2005 | BP 1.8 L |
| Ford | Miata | 1994-2005 | BP 1.8 L |
| Ford | MX-5 | 1994-2005 | BP 1.8 L |
| Mazda | Escort GT | 1994-2005 | BP 1.8 L |
| Mazda | Miata | 1994-2005 | BP 1.8 L |
| Mazda | MX-5 | 1994-2005 | BP 1.8 L |

