Understanding Camshaft Basics

The camshaft is the brain of your engine, controlling when the intake and exhaust valves open and close. It consists of a series of lobes that push on lifters, pushrods, and rocker arms to actuate the valves. Key camshaft specifications include lobe lift, duration (how long the valve stays open), lobe separation angle (LSA), and overlap. Even small changes in these numbers can dramatically shift the engine’s power curve and idle quality.

  • Lobe Lift & Valve Lift: Lobe lift is the actual height of the lobe; multiplied by rocker arm ratio you get valve lift. More lift generally flows more air at high RPM.
  • Duration: Measured in crankshaft degrees. Longer duration shifts power higher in the RPM band, but can hurt low-end torque and idle smoothness.
  • Lobe Separation Angle (LSA): Tighter LSA (e.g., 108°) increases overlap, moves torque higher, and creates a choppy idle. Wider LSA (e.g., 114°) smoothes idle, broadens the torque curve.
  • Overlap: When both intake and exhaust valves are open briefly. Increases high-RPM power but can reduce cylinder pressure at low RPM.

Matching these parameters to your engine’s displacement, compression ratio, cylinder head flow, and intended use is the essence of cam selection. A custom grind allows you to dial in the exact profile your combination needs—something an off-the-shelf cam may not do perfectly.

Why Choose a Summit Racing Custom Grind?

Summit Racing offers a custom camshaft service that lets you specify lobe profile, LSA, advance/retard, and even brand (Comp Cams, Lunati, etc.) through their own grinding network. This is not a pre-packaged shelf cam. You fill out a form with your engine specs and performance goals, and Summit’s experts recommend a specific grind. The key advantages are personalization and cost-effectiveness—often a custom grind costs only slightly more than an off-the-shelf model, while giving you a profile optimized for your exact setup.

For example, a Summit Racing custom grind aimed at a 20-25 horsepower increase typically targets street/strip builds with moderate compression (9.5:1 to 10.5:1) and mild valve lift to avoid clearance issues. Many users report gains in the advertised range with a noticeable improvement in throttle response and mid-range torque.

External link: Summit Racing Custom Camshaft Service

Performance Expectations: 20-25 HP Gain

The 20-25 horsepower claim is realistic for a small-block V8 (e.g., 350 Chevy) or similar displacement when combining a properly chosen cam with supportive modifications. On a stock engine, simply swapping a cam won’t deliver that number—you need adequate airflow through the intake, heads, and exhaust. A custom grind built for your existing heads and compression ratio can unlock that potential without requiring a full rebuild.

Typical dyno results show gains concentrated in the 2,500-5,500 RPM range, with peak power occurring 300-500 RPM higher than the stock cam. Torque often increases by 15-20 lb-ft below the peak, improving seat-of-the-pants response. Be aware that the actual gain depends on engine size, vehicle weight, gearing, and drivetrain losses.

External link: Hot Rod: How to Dyno Test a Performance Camshaft

Cost-Benefit Analysis of a Summit Racing Custom Grind

Initial Investment

  • Camshaft Price: Summit Racing custom grinds typically range from $120–$250 depending on lifters and finish treatment (e.g., nitrided or not). This is competitive with off-the-shelf cams.
  • Lifters: Never reuse old lifters on a new flat-tappet cam. A set of quality lifters runs $80–$150.
  • Valve Springs & Retainers: If the cam lift exceeds stock spring limits, upgrade springs ($50–$100). Retainers optional but recommended for high-RPM use.
  • Pushrods & Timing Set: Budget $40–$80 for pushrods if length changes; a double-roller timing set is ~$40.
  • Installation Labor: Professional installation adds $400–$800 depending on shop rates and whether additional work (e.g., head removal) is needed. DIY saves that cost but requires mechanical skill and tools.

Additional Costs to Consider

  • Engine Tuning: After cam swap, recalibrating the ECU (if fuel injected) or re-jetting the carb is essential. Tuning can cost $200–$500 for a dyno session or mail-order tune.
  • Supporting Parts: A high-flow intake (e.g., aftermarket intake manifold) and headers may be needed to fully realize the cam’s potential. These can add $500–$1500, but they are often part of a broader build.

Benefits

  • Power Gain: 20-25 HP is a tangible improvement for many driver-oriented builds. In a 3,200 lb car, that’s roughly a 0.3-0.5 second reduction in quarter-mile time.
  • Torque Curve: Improved mid-range torque makes the car more responsive in daily driving and passing situations.
  • Sound & Driving Experience: A mild custom cam often provides a pleasing lope without sacrificing daily drivability.
  • Longevity: Custom grinds can be designed with gentle ramps and proper lifter rotation to reduce wear, especially important for flat-tappet designs that require zinc-rich oil.

When you total the parts cost (cam, lifters, springs, gaskets, timing set) to about $350–$500 plus tuning, the cost per horsepower gain works out to $15–$25 per HP. That’s one of the best bang-for-buck upgrades in engine performance.

Supporting Modifications Needed

To ensure the Summit Racing custom grind delivers its 20-25 HP and doesn’t cause mechanical issues, plan for these upgrades:

  • Valve Springs: Verify installed height and seat pressure. A cam with more lift requires springs that prevent coil bind and control valve float. Summit offers matched spring kits.
  • Pushrods: Check length with a pushrod checker. Incorrect length leads to poor rocker geometry and potential valve train noise.
  • Timing Chain Set: Replace old chain with a quality set. A cam swap is the perfect time to address that worn chain.
  • Intake Manifold & Carburetor/Throttle Body: A stock intake may restrict flow. A Performer RPM or similar dual-plane manifold works well with this cam range. For fuel-injected engines, consider a tune from HP Tuners or equivalent.
  • Exhaust System: Headers and free-flowing exhaust help the engine breathe out. Expect a few extra HP if you upgrade from manifolds.
  • Oil & Zinc Additive: Flat-tappet cams need adequate zinc (ZDDP) to prevent lobe wear. Use a break-in oil or supplement.

External link: Engine Builder: Choosing the Right Valve Springs

Installation Overview

Installing a camshaft is a major engine operation that typically involves removing the intake manifold, valve covers, timing cover, and sometimes the radiator. Here is a high-level sequence:

  1. Drain coolant and disconnect battery. Remove air cleaner, carb/throttle body, distributor, and spark plugs.
  2. Remove intake manifold, valve covers, rocker arms, pushrods, and lifters. Label components for reuse if desired.
  3. Remove timing cover, timing chain, and gears. Rotate engine to align timing marks.
  4. Carefully slide out the old camshaft, supporting the lobes to avoid damaging cam bearings.
  5. Install new camshaft with generous assembly lube on each lobe and journals. Rotate to align timing marks per manufacturer instructions.
  6. Reinstall timing set, torque bolts to spec. Install timing cover with new gasket.
  7. Install lifters (dip each in ZDDP oil), pushrods, rocker arms. Adjust valve lash per cam specs.
  8. Reinstall intake manifold, valve covers, distributor (set timing to static). Refill coolant and oil.
  9. Start engine and run at 2000-2500 RPM for 20 minutes for break-in. Then adjust timing, check for leaks.

Pro tip: Use a cam button if the cam has a roller option; Summit can advise. For flat-tappet cams, break-in is critical—never let it idle during the first 20 minutes.

Tuning for Maximum Gains

Without proper tuning, a new cam can run lean or rich, causing lost power and even engine damage. For carbureted engines, you may need to re-jet the carburetor, adjust the power valve, and possibly re-curve the distributor. For EFI, a custom tune via HP Tuners, SCT, or a similar system is highly recommended.

Tuning steps typically include:

  • Adjust idle speed and mixture (fuel injected systems may need idle air control recalibration).
  • Modify fuel tables for the new airflow demand.
  • Adjust spark advance timing curve to match cam’s powerband.
  • Wideband oxygen sensor feedback during dyno tuning ensures safe air-fuel ratios.

A well-tuned engine can realize the full 20-25 HP gain; a poorly tuned one may see only 10 HP or less, with poor drivability.

External link: HP Tuners – ECU Tuning Software

Pros and Cons of a Summit Racing Custom Grind

Pros

  • Tailored to your specific engine combination, unlike generic shelf cams.
  • Cost-effective – often same price as off-the-shelf but with better results.
  • Summit’s technical support helps select the right profile; they have years of data.
  • Gains of 20-25 HP are realistic and drivable.

Cons

  • Requires supporting mods and careful installation; not a one-part bolt-on.
  • Flat-tappet cams require break-in and quality oil; modern oils have reduced zinc.
  • May shift powerband slightly higher; if your engine is already low-compression, gains may be smaller.
  • Custom grinds are not returnable if you change your mind—so be sure of your specs.
  • Lead time (typically a few days to a week) versus walking into a store.

Alternatives to Summit Racing Custom Grinds

Summit’s service is excellent, but you can also consider:

  • Comp Cams Xtreme Energy – well-known off-the-shelf profiles that offer similar gains for many common engines.
  • Howards Cams Custom Grind – another reputable grinder with direct ordering.
  • Bullet Cams – specialize in custom grinds, often used by engine builders.
  • Lunati – provides custom grinding through Summit as well.

Each has its own lobe designs and price points. Summit’s advantage is simplicity: one phone call or online order with their tech desk guiding you.

Conclusion: Is the Summit Racing Custom Grind Right for You?

For enthusiasts building a street-driven performance engine and seeking a cost-effective 20-25 horsepower bump, a Summit Racing custom grind camshaft is a smart investment. The cost per horsepower is low compared to other modifications, and the ability to tailor the profile to your exact engine (displacement, compression, heads, exhaust) ensures you aren’t leaving power on the table. Pair it with proper valve springs, pushrods, timing set, and a professional tune, and you’ll achieve a satisfying upgrade in both power and driving experience.

Before ordering, gather your engine specs and be honest about your intended RPM range and drivability priorities. Summit’s techs can then grind the perfect profile. With careful planning and installation, that 20-25 horsepower goal is within reach.