ProBoost Race 281/271 H.F.T Camshaft Small Block Chevy V8 (262–400)

Redline Cams ProBoost Race 281/271 Hydraulic Flat Tappet Camshaft Installation Guide

Application: Small Block Chevy, Hydraulic Flat Tappet, Race Engine, 15–20 psi Boost

Important Safety & Preparation Notes

• Race Engine Only: This camshaft is designed for high-performance applications; do not use in street engines without modification.

• Tools & Cleanliness: Engine cleanliness is critical—any debris can damage lifters or cam lobes.

• Oil System Readiness: High-pressure oiling is mandatory for hydraulic flat tappets under boost. Ensure pump, passages, and filter are in excellent condition.

• Break-In Importance: Failure to properly break in a hydraulic flat tappet cam will result in immediate lobe or lifter failure, especially under forced induction.

Required Tools & Materials

• Torque wrench (inch-lbs and ft-lbs)

• Dial indicator and degree wheel

• Camshaft degreeing kit

• High-pressure moly-based cam lube

• Assembly lube for lifters and pushrods

• Plastigage (optional, for checking bearing clearances)

• Timing chain installation tools

• Harmonic balancer installer

• Engine oil with ZDDP for flat tappets (break-in oil recommended)

Step 1: Engine Block Preparation

• Inspect the block for burrs, casting flash, or debris. Clean thoroughly with solvent.

• Check main bearings for wear, measure clearances, and ensure crank journals are clean and polished.

• Inspect cam bearings. Replace any showing scoring or excessive wear; boost applications magnify cam stress.

• Verify crankshaft end play is within Small Block Chevy spec (typically 0.003–0.007").

Step 2: Remove Existing Camshaft

• Drain oil and remove oil pan.

• Remove timing cover, harmonic balancer, and timing chain assembly.

• Remove lifters, keeping them organized in their original positions to prevent wear pattern mismatch.

• Carefully slide out the old camshaft, supporting it to avoid scratching journals or lobes.

Step 3: Inspect & Prepare Camshaft and Lifters

• Inspect cam lobes for wear or damage.

• Replace hydraulic flat tappet lifters with high-pressure lifters rated for forced induction.

• Lightly coat cam lobes and journals with high-pressure cam lube; do not skimp—boosted engines are unforgiving.

• Ensure lifters slide freely in their bores; remove any burrs or debris.

Step 4: Install ProBoost Race Camshaft

• Carefully insert camshaft into the block using even pressure; rotate gently to reduce friction.

• Rotate cam several times by hand to verify free movement.

• Inspect all journal seating; cam should not bind or contact the block.

Step 5: Install Timing Chain and Gears

• Install timing gear set according to Redline specifications:

  • Intake Duration @ .050": 224°

  • Exhaust Duration @ .050": 214°

  • Advertised Duration: 271°/261°

  • Lobe Separation Angle (LSA): 115°

• Degree the camshaft carefully using dial indicator and degree wheel:

  • Check intake centerline (ICL)

  • Verify exhaust centerline (ECL)

  • Confirm TDC alignment with crank.

• Proper degreeing ensures max performance, especially under boost.

Step 6: Lifter Installation

• Apply assembly lube to lifter bottoms and sides.

• Insert lifters into original or recommended positions; note that high-pressure lifters may need slightly looser clearance initially.

• Verify lifters move freely in bores and that there is no binding with the cam lobes.

Step 7: Valve Train Assembly

• Install pushrods, ensuring proper length for full valve lift.

• Install rocker arms, torque bolts to spec.

• Set initial hydraulic lifter preload: typically zero lash for flat tappets in race configuration.

• Manually rotate engine several times to verify full range of motion without binding.

Step 8: Final Engine Assembly

• Install timing cover and harmonic balancer.

• Reinstall valve covers.

• Prime oil system with racing assembly oil or pump pre-oiling system to ensure oil reaches cam and lifters before engine start.

Step 9: Cam Break-In Procedure

Critical for Hydraulic Flat Tappets under Boost:

• Fill with high-zinc break-in oil.

• Start engine and maintain 2,500–3,000 RPM for 20–30 minutes.

• Avoid load, boost, or extended idle; maintain oil pressure above 40 psi.

• After initial run, change oil and filter to remove cam debris.

• Resume normal operation; gradually introduce boost.

Step 10: Tips for Boosted Race Engines

• Use high-pressure, high-volume oil pump.

• Consider high-zinc racing oil throughout engine life.

• Monitor cam and lifter wear periodically.

• Avoid prolonged high-RPM operation before proper break-in.

• Check timing chain alignment after initial run due to slight stretch.

Technical Summary

• Duration: 224°/214° @ .050" (271°/261° advertised)

• Lift: .460"/.440"

• LSA: 115°

• RPM Range: Optimized for 4,500–7,500 RPM race operation under 15–20 psi boost

This guide ensures maximum cam life and performance for forced induction hydraulic flat tappet race engines while minimizing risk of premature failure.