Camshaft Selection Guide: Troubleshooting Poor Idle and Power Loss After Installing a Richmond Racing Cam

Installing a new camshaft is one of the most rewarding upgrades you can make to your engine, but it’s also one of the most delicate balancing acts in performance tuning. A Richmond Racing cam promises big gains, but if you’re fighting poor idle and power loss after installation, you’re not alone. The good news: these issues are usually fixable and often stem from mismatched specs or overlooked supporting mods. This expanded guide goes beyond the basics to help you diagnose, solve, and prevent the problems that can turn your cam swap into a frustration.

Understanding Camshaft Specifications: Beyond Lift and Duration

Before diving into troubleshooting, you need a solid grasp of what each camshaft spec does to your engine’s behavior. Richmond Racing offers a range of cams for small-block and big-block Chevys, Fords, and more. Let’s break down the key variables.

Lift and Duration

Lift is how far the valve opens. More lift can improve airflow, but it also increases stress on the valvetrain. Duration is how long the valve stays open, measured in crankshaft degrees. Longer duration typically shifts the power band higher in the RPM range. A cam with too much duration for your engine’s displacement can kill low-end torque and make idle rough.

Lobe Separation Angle (LSA)

LSA is the angle between the intake and exhaust lobe centers. A tighter LSA (e.g., 108°) increases overlap, which can give you a lopy idle and more top-end power but hurts vacuum and can cause poor idle quality. A wider LSA (e.g., 114°) smooths the idle and improves manifold vacuum, often better for street-driven cars. Richmond Racing cams typically provide LSA numbers in their catalog – always match the LSA to your intended use.

Centerline and Advance/Retard

The cam’s centerline can be ground with a built-in advance or retard. Advancing the cam shifts the power band lower; retarding it moves power higher. If you installed a cam and lost bottom-end power, it might be ground with a retarded centerline (or you may have installed it incorrectly). Always degree your cam to verify its installed position.

Why Poor Idle Happens After a Cam Swap

A rough or unstable idle is often the first sign of a mismatch between the cam and the rest of the engine. Here are the common causes and how to fix them.

Vacuum Leaks

A cam with high overlap reduces manifold vacuum. If you already have a small vacuum leak, it becomes more noticeable at idle. Check all vacuum lines, the intake manifold gaskets, and the brake booster line. Use a smoke machine or carb cleaner to pinpoint leaks. Even a small leak can drop idle quality dramatically.

Ignition Timing Tuning

Aggressive cams often benefit from more initial timing at idle. You may need 16–20 degrees of base timing, sometimes more. If your timing is too low, the engine will stumble and stall. Consider using a vacuum advance can that is adjustable – many performance cams require limiting or tuning the vacuum advance to prevent detonation and improve idle stability.

Carburetor or Fuel Injection Tuning

With a radical cam, the carburetor’s idle circuit may not supply enough fuel. You may need to enlarge the idle feed restrictors or adjust the air/fuel mixture screws. For EFI setups, the idle air control (IAC) position and fuel tables may need recalibration. Richmond Racing cams often create a pulse wave that can disrupt the fuel signal – especially with a carburetor, a lightweight specific idle circuit tune is essential.

Incorrect Idle Speed and Mixture Settings

Many builders simply turn the idle speed screw higher to compensate, but that can lead to exposed transfer slots in the carburetor, causing hesitation and poor throttle response. Instead, you want the idle speed low enough (600–800 RPM) while maintaining stable fuel metering. Use a vacuum gauge to set the mixture for maximum steady vacuum, then adjust speed.

Diagnosing Poor Idle: Step-by-Step

Follow this guided diagnostic sequence:

1. Vacuum check: Measure manifold vacuum at idle. A stock cam might pull 18–20 inHg; a big cam could drop to 8–12 inHg. If vacuum is erratic or very low, suspect a leak or cam overlap issue.
2. Ignition timing: Confirm base timing with a timing light. Adjust to manufacturer’s suggestion or start at 16° initial and see if idle smooths.
3. Fuel delivery: Check fuel pressure (carbureted: 5–7 psi, EFI: 40–60 psi). Ensure the float level is correct.
4. Throttle position sensor (TPS) calibration: For EFI, ensure TPS reads 0% at idle and that idle set screw is not holding the throttle open past the normal setting.
5. Cam degree verification: If all else fails, pull the timing cover and degree the cam. A misaligned cam timing can cause extreme idle issues. Richmond Racing includes cam cards – make sure intake centerline matches the card within 1°.

Power Loss After Installing a Richmond Racing Cam

You expect gains, but sometimes the car feels weaker than before. Power loss can be subtle or dramatic. Let’s break it down.

Over-Camming: Too Much Duration for Your Combo

Installing a cam designed for a 383 stroker in a stock 350 is a common mistake. The engine can’t utilize the longer duration, so it loses compression and torque below 3,500 RPM. Power loss isn’t a failure of the cam – it’s a mismatch. Richmond Racing cams are designed for specific cube ranges. If your engine has low static compression (below 9.5:1), a large cam will make it a dog.

Compression Drop and Dynamic Compression

Longer intake timing closes the intake valve later, bleeding off cylinder pressure at low RPM. This reduces dynamic compression. To restore power, you need either higher static compression or forced induction. Poor power below 3,000 RPM is almost always a dynamic compression issue. Check your cam’s intake closing point (ICA) – if it’s above 60° ABDC at 0.050”, your dynamic compression will be low.

Exhaust Restrictions

A cam with more lift and duration requires a free-flowing exhaust. If you’re running stock manifolds or small-diameter headers, the engine will choke. Richmond Racing cams often have aggressive exhaust lobes – the engine needs to breathe out just as well as it breathes in. Consider upgrading to long-tube headers and a 2.5” or 3” exhaust with high-flow mufflers.

Fuel System Limitations

More air demand means more fuel. If your fuel pump can’t keep up (especially at high RPM), the engine will lean out and lose power. Symptoms: a sudden power drop after 4,500 RPM, or the car feels flat up top. Upgrade to a high-volume mechanical pump or a robust electric pump with a return-style regulator.

Troubleshooting Power Loss: Practical Steps

1. Verify cam timing: Degree the cam. Even a 2° error can shift power band significantly. Check intake centerline and compare to cam card.
2. Check valve clearance: With high lift cams, piston-to-valve clearance can be tight. If valves hit pistons (even slightly), power suffers. Use clay or a dial indicator to confirm at least 0.080” intake and 0.100” exhaust clearance.
3. Evaluate valvetrain stability: Weak valve springs or improper installed height can cause valve float, killing power at high RPM. Richmond Racing cams often require dual springs with 130–160 lbs seat pressure. Check spring pressure with a valve spring tester.
4. Measure exhaust backpressure: A simple test: tee into the O2 sensor bung or a port after the manifold and use a pressure gauge. At wide-open throttle, backpressure should not exceed 1.5–2 psi. Higher indicates a restriction.
5. Check air/fuel ratio: Use an wideband O2 sensor. Aim for 12.5–13.0:1 at wide open throttle, 14.7:1 at idle. If it’s lean, you need bigger jets or fuel injectors.

Valvetrain Considerations for Richmond Racing Cams

The cam is only part of the system. Your valvetrain must support it.

Valve Springs

Never reuse old springs with a new cam. Richmond Racing recommends specific spring part numbers for each cam model. If you run a high-lift cam (over 0.550”) with weak springs, you risk coil bind and lost power. Always check installed height and shim as needed.

Pushrods and Rockers

After cam installation, check pushrod length. A change in base circle can alter rocker geometry. Use an adjustable pushrod checker to determine the correct length for proper rocker arm sweep. Incorrect geometry wastes power and wears parts prematurely.

Lifter Selection

Richmond Racing cams are compatible with both hydraulic and solid lifters, but you need to match the lobe profile. Retrofit hydraulic rollers are common for Gen I small blocks. Ensure you use the correct tie bar or link bar for your engine.

Choosing the Right Richmond Racing Cam: A Decision Framework

To avoid idle and power problems from the start, select the cam based on your entire combo – not just engine size.

Engine Use	Compression Ratio	Recommended Cam Specs (Example Small Block Chevy 350)
Street cruiser, daily driver	9.0–9.5:1	0.450–0.480 lift, 212–220° duration @0.050, 112–114 LSA
Street/strip, mild performance	9.5–10.5:1	0.480–0.520 lift, 224–236° duration @0.050, 110–112 LSA
Strip/race, 3,500+ RPM power	10.5:1+ or forced induction	0.550+ lift, 240–260° duration @0.050, 106–110 LSA

Richmond Racing’s website provides detailed cam cards with recommended heads, intake, and compression. Check their technical resources before buying. If you already bought a cam that doesn’t match, consider swapping for a better-suited model – it’s cheaper than fighting issues forever.

Installation Best Practices to Prevent Problems

Cam Break-In

If you’re using a flat tappet cam (non-roller), proper break-in is crucial. Use a high-zinc break-in oil, run at 2,000–2,500 RPM for 20 minutes with varying RPMs. Many flat tappet failures are due to improper break-in. Richmond Racing cams have specific break-in instructions – follow them to the letter.

Timing Chain Installation

Use a quality double-roller timing set. Set it according to the cam card – often “straight up” (0° advance) is fine, but some cams prefer 2–4° advance for street use. Never guess – degree the cam.

Lubrication

Apply cam lube to every lobe and lifter foot. Pre-oil the engine before first start to ensure oil reaches all bearings. A dry start can kill a cam in seconds.

When to Seek Professional Help

If you’ve gone through all the troubleshooting steps and still have poor idle or power loss, consider having the car dyno-tuned by a shop experienced with Richmond Racing cams. A skilled tuner can dial in the ignition timing curve, fuel mixture, and even make cam adjustments if a performance valve spring upgrade is needed. Sometimes, the issue is not the cam but a subtle problem like a weak fuel pump or a misaligned balancer.

Conclusion: Get the Most from Your Richmond Racing Cam

A quality camshaft like those from Richmond Racing can transform your engine – but only if you pay attention to the supporting system. Poor idle and power loss are almost always symptoms of a mismatch in specs, tuning, or installation. By systematically checking vacuum, ignition timing, fuel delivery, valvetrain components, and cam degree, you can eliminate common problems and enjoy the full benefit of your cam upgrade. Remember that changing the cam changes the engine’s personality – you may need to adjust your driving style and accept a lumpy idle if that’s what the cam delivers. For further reading, this article from EngineLabs explains cam specs in depth, and this step-by-step guide on Hot Rod will help you degree your cam accurately. With patience and the right approach, your Richmond Racing cam will deliver the power and sound you built for.