Brian Crower Dual Valve Springs & Retainers for K20/K24/F Series

Brian Crower Dual Valve Springs & Retainers - K20, K24 & F-Series

Valve springs are the part of a cam upgrade people underestimate. Bigger cams and higher rpm ask far more of the springs than the factory profile does, and stock springs are what let go first. These BC dual springs are wound by PAC Racing from high grade chrome silicone alloy, rated to 0.550" net cam lift, and they're the supporting hardware serious K-series and F-series builds are built around.

Read This If Your Head Is 2004 Or Newer

Important warning, and it affects a lot of people.

Honda changed the keeper groove angles on late model cylinder heads. If yours is 2004 or newer, your factory keepers may not fit the BC retainers properly, and Brian Crower is explicit that this can cause damage.

The fix is BC2940 keepers, sourced alongside this kit. If there's any chance your head is a late model, get them in the same order rather than finding out with the head apart or, worse, after the engine is running.

This applies to both the BC2010 titanium and BC2011 steel retainers, so it's not something you avoid by picking one over the other.

Titanium Or Steel Retainers?

Two versions of the kit, and the difference is what the retainers are made of.

BC0040 uses titanium retainers (BC2010). Lighter, which reduces valvetrain mass and helps the springs control the valve at high rpm. This is the choice for a race or high rpm application where every gram of reciprocating weight matters.

BC0040S uses steel retainers (BC2011). Heavier than titanium but considerably more durable over time, which is why Brian Crower positions steel for streetability. If the car sees regular road use and you want the valvetrain to last without thinking about it, steel is the sensible pick.

Honest guidance: titanium is the right call for a dedicated race engine, steel for anything that's still a street car. Titanium retainers are a wear item in a way steel isn't, and on a car doing thousands of road miles a year that matters more than the weight savings.

Why Springs Come First

Worth explaining, because it's the reason these are a hard requirement rather than an upgrade.

Your valve spring's job is closing the valve, and it has to do that faster than the cam is trying to open it. Increase lift or add duration and the spring has more work to do in less time.

When a spring can't keep up, the valve floats. It doesn't fully close when it should, and on an interference engine that means a valve sitting in the path of a piston. That's the failure mode, and it's why every cam manufacturer specifies springs alongside their profiles.

These are rated to 0.550" net cam lift, which covers the aggressive profiles people run on these engines.

PAC Racing Construction

BC valve springs are wound by PAC Racing from the highest grade, super clean chrome silicone alloy, using proprietary processing for consistent pressures across the set.

That consistency matters more than the headline pressure figure. A set where one spring sits meaningfully off the others means one valve behaving differently from the rest, which shows up as a cylinder that doesn't match on a dyno and, at the limit, a valve that floats before the others do.

Specifications

Do It While The Head Is Off

Installing valve springs means the head is apart, which is most of the labor. Use the access.

Inspect your valve guides and seals while everything is exposed, since those wear on a high mileage engine and reaching them later means the same teardown. And if cams are anywhere in your plan, this is the moment to fit them rather than doing this job twice.

Fitment

Honda and Acura K20A, K20Z3, K24A2, F20C, and F22C engines.

BC0040 (titanium retainers) or BC0040S (steel retainers). Heads from 2004 onward may require BC2940 keepers.

Who Should Run These

This is for anyone fitting aggressive cams, and for the builder who's chasing rpm and needs the valvetrain to keep up. It's supporting hardware rather than a power part, which is exactly why it gets skipped and exactly why skipping it is expensive. Pick titanium for a race engine or steel for a street car, sort your keepers if you're on a late head, and build the top end properly.

Fits: Honda and Acura K20A, K20Z3, K24A2, F20C, and F22C. Part numbers: BC0040 (titanium retainers) and BC0040S (steel retainers). Spring: BC1040 dual, wound by PAC Racing from chrome silicone alloy. Rated to: 0.550" net cam lift. Includes: springs, retainers, and spring seats. Important: 2004 and later cylinder heads may require BC2940 keepers due to changed keeper groove angles.