Mercury – Valve Spring Kit | 357 CT Iron Heads | Precision Steel Components | 8M0120862

Overview

Anyone who’s spent time around a circle track engine knows there’s a rhythm to performance—an even, confident pulse that tells you the valvetrain is working exactly as it should. When that rhythm slips, even just a little, you feel it right away. That’s why replacing worn components with trusted parts matters so much. The Quicksilver 8M0120862 Valve Spring Kit brings back that steady, responsive feel that makes the 357 CT crate engine such a favorite among racers who want dependable power without breaking from factory-sealed rules.

There’s a comfort in knowing the parts under your valve covers are built to the same exacting standards as the ones your engine rolled out with. This kit restores that confidence, helping your engine breathe cleanly, rev freely, and hold its composure lap after lap.

Key Features

• Designed specifically for the Quicksilver 357 CT circle track crate engine
• Replaces original valvetrain components to maintain sealed-engine compliance
• Built for use with beehive valve springs
• Precision-machined for strength, stability, and consistent valve control
• Helps preserve factory performance characteristics and reliability

Engine & Boat Compatibility

• Intended for Quicksilver 357 CT crate engines equipped with iron cylinder heads
• Suitable for circle track race applications where sealed-spec compliance is required
• Fits engines using beehive-style valve springs
• Ideal for competitive racers, engine builders, or performance shops maintaining sealed engines

Performance & Practical Benefits

A healthy set of valve springs does more than hold everything in time—it keeps your engine feeling tight, lively, and willing to rev when you lean into the throttle. With worn springs, you’ll notice hesitation, valve float, or a lazy top end that takes the excitement out of running hard laps. This kit restores the crisp, predictable response that makes the 357 CT such a pleasure to race.

Precision manufacturing ensures every spring matches Mercury’s strict specs for seating pressure and durability. That consistency matters, especially when the goal is to keep a sealed engine performing exactly as intended. You’ll feel the difference in smoother mid-range pull, more stable high-rpm operation, and a valvetrain that stays quiet, controlled, and trustworthy.

Installation is straightforward for anyone familiar with valvetrain service, and once everything is buttoned back up, the engine settles into a steady idle and pulls cleanly through the rev range—just the way a crate motor should.

Why Buy OEM

• Genuine Mercury Marine part designed to match original factory specs
• Guarantees sealed-engine legality for sanctioned circle track events
• Offers longer life and more consistent performance than many aftermarket alternatives
• Provides the correct pressure profile for beehive valve spring setups
• Helps protect engine reliability, ensuring every lap counts

When you’re racing a sealed engine, cutting corners isn’t an option. OEM parts keep you compliant, competitive, and confident.

FAQ

Q1: Which engines does this valve spring kit fit?

It’s made specifically for the Quicksilver 357 CT crate engine with iron heads and beehive springs.

Q2: What makes it better than aftermarket parts?

OEM components match exact factory calibration, keeping your sealed engine legal and consistent.

Q3: How can I confirm this is the right replacement?

If you’re running a 357 CT engine and maintaining sealed compliance, this is the correct kit.

Q4: Is it suitable for both saltwater and freshwater?

While primarily used in racing applications, the materials are engineered for durability in any environment.

Q5: Is installation straightforward?

Yes—anyone experienced with valvetrain service can install it with standard tools.