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SKU: 3121-8
GSC Honda K20C1 CTR (STD) Exhaust Valve Guide - Set of 8
GSC Power-Division exhaust valve guides (part GSC3121-8) deliver exact fitment for Honda K20C1 engines in 2017+ Civic Type R models. This standard size set of 8 supports high-performance valvetrain upgrades with reliable sealing and heat management. Precision dimensions prevent valve wobble for consistent power delivery.
Key Features
- Manganese Bronze Material: Provides wear resistance and thermal conductivity for extended life in turbocharged K20C1 applications
- Standard Sizing (Set of 8): Total length 1.970in/50.04mm, outer diameter 0.4357in/11.07mm, valve stem clearance for 5.5mm stems
- Oversize Options Available: +0.001in and +0.003in guides sold individually for worn cylinder heads (GSC3121-1, GSC3121-3)
- Direct K20C1 Fitment: Engineered specifically for Civic Type R exhaust valves to maintain factory tolerances under boost
- Performance Durability: Handles high RPM and heat cycles better than stock guides for track or street use
Product Notes
- Standard guides sold as complete set of 8. oversizes sold individually
- Inspect cylinder head valve seats before installation for compatibility
- Special order item. allow 3-5 business days for processing
Installation Notes
- Professional installation recommended.
- Valve guide driver tool required for press-fit installation into aluminum head
- Compatible with stock or aftermarket exhaust valves. measure stem clearance post-install
This Part Fits
| Year | Make | Model | Submodel |
|---|---|---|---|
| 2017-2021 | Honda | Civic Type R | |
| 2023-2024 | Honda | Civic Type R |
Why Choose GSC Power-Division?
- Trusted by Honda tuners for valvetrain components since 2005
- Manufactured in USA with tight tolerances for racing reliability
- Backed by real-world testing in high-boost K-series engines
Frequently Asked Questions
-
Q: Will these fit the 2023 Honda Civic Type R K20C1?
A: Yes, these standard guides match the K20C1 specs in both FK8 (2017-2021) and FL5 (2023+) Civic Type R models -
Q: What material are the valve guides made from?
A: Manganese bronze alloy for optimal strength, heat dissipation, and low friction with 5.5mm valve stems -
Q: What is the warranty on GSC valve guides?
A: One-year unlimited mileage warranty against manufacturing defects when installed by certified shop
Shipping & Handling
- Method: UPS Ground or USPS Priority
- Availability: In stock - ships same or next business day
- Packaging: Compact box 6x4x2 inches
- Weight: 0.8 lbs
GSC Power Division
GSC Power Division is a manufacturer of precision-engineered camshafts, valve springs, and valvetrain components designed for high-performance and competition engines across domestic, import, and diesel platforms. Founded by engineers with deep roots in motorsport, GSC Power Division components are machined to exacting tolerances and heat-treated to survive the demands of forced induction and high-rpm applications that destroy stock valvetrain parts. The brand is particularly well-known in the Mitsubishi Evo, Subaru STI, Nissan RB, and Toyota 2JZ communities where aggressive camshaft profiles are essential for extracting maximum power from turbocharged four-cylinder and six-cylinder engines. Whether building for drag racing, road course competition, or a high-powered street car, GSC Power Division camshafts and valve springs are a proven upgrade path. Popular Upgrades GSC Power Division S1, S2, and S3 camshafts are the most popular selections, with each profile offering progressivel...
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