The Comprehensive LS Engine Building Guide from Start to Finish

Introduction

This tutorial is designed to guide you through the process of building an LS engine from start to finish. Whether you're a novice or someone with experience in engine building, this comprehensive step-by-step guide will help you navigate the complexities of the rebuild process, ensuring you understand each critical step along the way.

Chapter 1: Preparing the Components

• Soaking the Lifters

  • Place lifters in a Ziploc bag and fill with 30 weight oil.
  • Allow them to soak to prevent bum lifters upon first start.

• Cleaning the Pistons

  • Remove the piston rings using a pick tool.
  • Clean out carbon buildup from the ring grooves to avoid binding.

Chapter 2: Installing the Crankshaft

• Setting up the Crankshaft

  • Apply assembly lube to the crankshaft bearings.
  • Carefully place the crankshaft into the engine block.

• Main Cap Installation

  • Use the following torque sequence:
    • Inner and outer bolts: 15 foot-pounds.
    • Inner bolts: 80 degrees torque angle.
    • Outer bolts: 51 degrees torque angle.
  • Apply RTV sealant to any reused side bolts to prevent oil leaks.

• End Play Measurement

  • Measure crank end play using a dial indicator. Aim for around 0.003 inches.

Chapter 3: Installing Connecting Rods and Pistons

• Piston Ring Clearance Calculation

  • For a stock rebuild, use the bore size (3.78) and multiply:
    • Top ring: 0.004 inches → 15 thousandths clearance.
    • Second ring: 0.005 inches → 19 thousandths clearance.

• Checking Piston Ring Clearances

  • Insert rings into the bore and check gaps using feeler gauges.
  • Ensure each ring is organized by bore for accurate clearances.

• Filing Piston Rings

  • Use a ring grinder to achieve desired clearance (aim for 20 to 21 thousandths).
  • Ensure rings are ground evenly and straight to avoid gaps.

• Piston Ring Orientation

  • Ensure the markings on pistons indicate the front.
  • Install rings according to their orientation (top ring up, second ring down).

• Piston Installation

  • Use a ring compressor to install pistons into the cylinder.
  • Lubricate the bearings and ensure proper alignment with the crankshaft.

Chapter 4: Installing the Camshaft and Timing Gear

• Installing the Camshaft

  • Apply assembly lube to the camshaft.
  • Carefully insert it into the engine block.

• Timing Gear Installation

  • Remove the lower timing gear if necessary and replace it.
  • Heat the new timing gear to ease installation (350°F for about an hour).

• Cam Gear and Timing Chain Installation

  • Align the timing chain with the correct tooth.
  • Ensure proper tension and alignment to avoid timing issues.

Chapter 5: Installing the Oil Pump and Lifters

• Oil Pump Installation

  • Line up the oil pump with the engine block and torque bolts to 18 foot-pounds.
  • Use Loctite on bolts to secure them.

• Installing Lifters

  • Ensure oil holes on lifters are correctly oriented (facing up).
  • Tighten retaining bolts to 106 inch-pounds.

Chapter 6: Checking Piston to Valve Clearance

• Using Play-Doh Method

  • Place a ball of Play-Doh on the piston to check clearance with the valves.
  • Rotate the engine and check impressions for contact.

• Adjusting Pushrod Length

  • Use a pushrod length checker to verify proper length (aim for 7.35 inches).
  • Adjust as necessary to ensure zero lash on rocker arms.

Chapter 7: Installing Cylinder Heads and Rocker Arms

• Cylinder Head Installation

  • Ensure the correct head gaskets are used (OEM recommended).
  • Torque cylinder head bolts in the specified sequence to yield.

• Rocker Arm Installation

  • Tighten rocker arms in the appropriate order, checking for zero lash and proper torque.

Chapter 8: Final Assembly Steps

• Installing Oil Pan and Covers

  • Use RTV sealant on the oil pan and torque down to 18 foot-pounds.
  • Ensure proper sealing to prevent leaks.

• Harmonic Balancer Installation

  • Utilize a harmonic balancer installer tool and torque to specified settings.

Conclusion

Building an LS engine is a meticulous process that requires attention to detail and patience. By following the steps outlined in this guide, you can successfully rebuild your engine with confidence. Remember to check clearances, use the right tools, and take your time to ensure each component is properly installed. Good luck with your engine build, and stay tuned for future projects where you can see your engine come to life!