LS Engine Reconditioning Methods
LS engine reconditioning restores performance, reliability, and engine life. To keep your car running well or build a strong engine. This process requires checks, machining, and expert assembly.
Oztrack Products and Services
LS Engine Reconditioning without the car
LS Engine Reconditioning with cam upgrade
LS Engine Reconditioning with stock cam
Why Recondition an LS Engine?
Solve performance issues like low compression or oil-burning
Extend engine life without a complete replacement
Prepare for more power with a solid foundation
Catch early signs of wear before major failure
Step 1: Full Disassembly and Inspection
Start with a complete teardown.
Remove all components, including crankshaft, pistons, rods, cam, and lifters.
Look for wear, scoring, oil sludge, and heat marks
Identify block version and casting to plan machining
Common LS issues: timing chain stretch, lifter wear, cracked heads, piston slap
This stage gives a complete picture of what needs replacing or machining.
Step 2: LS Engine Block Machining
Cylinder Honing
Refines the surface for proper ring sealing
Uses a plateau hone for oil control
Always use a torque plate to replicate real-world head clamping
Cylinder Boring
Removes material from worn or oval cylinders
Overbore to fit oversized pistons (e.g., from 4.000″ to 4.030″)
Essential for proper piston-to-wall clearance
Sleeving (If Required)
Some LS blocks need more than a simple bore.
Install better-quality iron sleeves into damaged or overbored cylinders
Ideal for cracked walls or builds converting 6.0L and 6.2L blocks to 427ci
The process involves precise cutting, interference fit, and then honing
Why sleeve an LS block?
Deep cylinder scoring
Extra strength for boost or nitrous
Adapting smaller displacement blocks for stroker builds
Deck Resurfacing
Machines the top of the block for a flat gasket surface
Prevents sealing issues from warpage or pitting
Line Honing
Aligns the crankshaft main bearing bores
Necessary if the block has main cap walk or replaced main caps
Step 3: Crankshaft and Rotating Assembly
Crankshaft
Inspect journals for scoring
Polish or grind undersize if needed
Check balance if changing rods or pistons
Connecting Rods
Check for twist and straightness
Resize big ends if bearings were worn
Replace rod bolts with ARP if upgrading
Pistons and Rings
Match to bore size
Choose forged pistons for power builds
Gap rings to match horsepower goals (e.g., wider gap for boost)
Engine Bearings
Mic journal and housing bores to select bearing thickness
Check oil clearances with plastic gauge or micrometres
Step 4: Cylinder Head Reconditioning
LS heads need more than a clean-up.
Disassemble and inspect
Pressure test for cracks
Cut multi-angle valve seats
Replace worn valves or guides
Mill heads to restore flatness or raise compression
Test valve springs for proper tension
Replace seals and locks
You can also port heads for better airflow if power is the goal.
Step 5: Oil System Refresh
A worn oil system ruins engine bearings.
Replace oil pump—don’t reuse
Upgrade to high-volume pump for loose clearances
Replace pickup tube O-ring
Step 6: Timing Set and Valvetrain
Replace these parts
Install new timing chain, sprockets, and dampener/tensioner
Replace lifters and pushrods
Measure pushrod length to match head and lifter setup
Use beehive or dual valve springs to match the camshaft lift
Step 7: Gaskets, Bolts, and Fasteners
Use new head gaskets, main bolts, and rod bolts
Follow torque angle specs, not just torque numbers
Use thread sealant or anti-seize where needed
Step 8: Engine Assembly
Take your time and double-check clearances.
Clean all parts thoroughly before installing
Use assembly lube on bearings, cam lobes, and valvetrain
Rotate the assembly after each step
Prime oil system with drill or pressure tank
Verify ring gaps, thrust clearance, and rod side play
Step 9: Break-In and Testing
How you start the engine matters.
Use break-in oil for the first 60 minutes of operation.
Run at 2,000–3,000 RPM with varied loads, then let it cool and repeat a few times at higher loads and rpm. Then, performance tune.
Monitor oil pressure, temp, and leaks
LS Engine Reconditioning Options
Stock Refresh
Replaces worn parts
Keeps OEM specs
Ideal for daily drivers
Street Performance Build
Cam upgrade
Possibly CNC Ported heads
Full Performance Exhaust
High Power Build
Sleeved block
Forged pistons and rods
CNC Ported heads and a larger duration camshaft.
Boost-ready
Should You Rebuild or Replace?
A reconditioned LS engine can often outperform a crate replacement. You get:
Known tolerances due to superior machining
Better components
Custom setup for your power goals
It comes down to what you want from your engine and how much you want to invest in doing it right.
You can research this topic more at https://enginelabs.com
Final Thoughts
A proper LS engine reconditioning is more than just swapping parts. It’s a series of precise, methodical steps that bring the engine back to full health or beyond.
If you are rebuilding an LS engine, consider the following questions:
Have I checked the cylinder wall condition and main cap alignment?
Do I know my oil clearances and ring gaps?
Have I upgraded what really matters for my power goal?
A strong and reliable LS engine begins at the machine shop but relies on meticulous assembly details.
Call Oztrack to discuss a plan for your engine reconditioning. We offer the services for engines freighted to us or with engine removal and reinstall.
