Engine Components

The best engine components are the ones matched to your exact engine and build goal: adjustable cam gears and camshafts to dial in valve timing, and valve springs, retainers and valves rated for the RPM and boost you plan to run. This collection covers the inside of the engine across Subaru, Mitsubishi, Honda and Toyota, so start with your engine code.

Engine components are the working parts under the valve covers and inside the block: cam gears, camshafts, valves, valve springs and retainers. Together they control when valves open, how far they open and how reliably the valvetrain survives higher RPM, bigger cams or added boost, so exact fitment matters more here than almost anywhere else on the car. Confirm the engine code first — a part listed for one generation rarely transfers to the next — match valve springs to your camshaft and intended redline, and treat adjustable cam gears as a tuning tool that only helps when set up properly, ideally on a dyno.

Brian Crower is a dedicated engine-internals specialist: intake valves for the WRX 2002-2014 and STI 2004-2019, plus staged camshafts such as a Stage 3 272/272 set for the Toyota 1JZ-GTE. The range centers on valvetrain parts for Japanese performance engines. Start with the Brian Crower Intake Valves for WRX and STI if you are planning a built head or cam swap.

BLOX Racing covers the Honda and Acura side in depth: dual valve springs for K20 and K24 i-VTEC engines, titanium retainers and springs for B-series, and adjustable cam gears for B-series, H23A and D-series. That makes it a practical one-stop valvetrain source for Honda builds, and the listings spell out the engine families each part fits.

AEM appears here through its Tru-Time adjustable cam gears, including a five-bolt design for the Mitsubishi Evo 8 and 9. AEM built its name on engine electronics and intakes, and Tru-Time applies the same tuning mindset to cam timing, in small, repeatable increments. The AEM Tru-Time Cam Gear for Evo 8 and 9 is the representative piece here.

Torque Solution supplies the precision billet hardware around the cams: a billet Mivec exhaust cam gear housing for the Evo X, a billet cam gear alignment tool for 4G63 engines, and a cam angle sensor bracket for the WRX 2002-2005. These are small, exact-fit machined components that make timing work cleaner. Planning a build? Pair this shelf with connecting rods, and read the EJ257 engine guide before a Subaru build.

Do I need a tune after camshafts or adjustable cam gears?

Usually, yes. Cams and changed timing alter how the engine breathes, so plan on tuning after the install.

How do I know an internal part fits my engine?

Match the engine code and generation in the listing title to your car, not just the model name — the same model can carry very different engines across years.

Should valve springs and retainers be replaced together?

It is good practice: springs and retainers work as a matched set, and mixing old retainers with new, stiffer springs can limit the benefit.

When does an engine need upgraded internals?

Common triggers are a rebuild, a bigger cam, a raised redline or a significant power increase. If the engine is apart, inspect the valvetrain while access is easy.