Types of 4G63T Engine
The 4G63T engine is a legendary 2.0-liter turbocharged inline-four cylinder powerplant developed by Mitsubishi Motors. First introduced in 1987, it became a cornerstone of Mitsubishi's performance lineup and has earned a cult following among automotive enthusiasts worldwide. While the non-turbo 4G63 versions are common, the turbocharged variants have achieved iconic status due to their remarkable power potential and motorsport heritage, particularly in World Rally Championship (WRC) competition.
Historical Note: The 4G63T engine powered the Mitsubishi Lancer Evolution series that dominated rally racing in the 1990s and early 2000s, cementing its legacy as one of the most tunable and robust factory turbocharged engines ever produced.
4G63T SOHC Engine
The Single Overhead Cam (SOHC) variant represents the earlier and simpler design of the 4G63T family. This configuration features a single camshaft controlling both intake and exhaust valves.
Key Characteristics:
- Simplicity: Less complex design with fewer moving parts
- Reliability: Known for excellent durability and straightforward maintenance
- Applications: Primarily used in earlier Mitsubishi Galant and Eclipse models
- Performance: Good power delivery for its era but modest by modern standards
- Economy: Generally more fuel-efficient than the DOHC variant
While lacking the peak performance capabilities of its DOHC counterpart, the SOHC 4G63T provides a balanced combination of reliability, simplicity, and adequate power that makes it an excellent choice for daily drivers.
4G63T 16V DOHC Engine
The Dual Overhead Cam (DOHC) 16-valve version represents the performance pinnacle of the 4G63T family. This sophisticated design employs separate camshafts for intake and exhaust valves.
Key Characteristics:
- Power: Significantly higher horsepower potential than SOHC version
- Efficiency: Better breathing capabilities and superior valve control
- Applications: Featured in legendary vehicles like the Lancer Evolution and Eclipse GSX
- Tuning Potential: Exceptional response to modifications and performance upgrades
- Revving: Capable of sustained high-RPM operation with excellent stability
The DOHC variant became the preferred choice for performance enthusiasts and formed the basis for Mitsubishi's most celebrated motorsport achievements, establishing a reputation for incredible durability even under extreme modification.
| Feature | 4G63T SOHC | 4G63T 16V DOHC |
|---|---|---|
| Valve Configuration | Single Overhead Camshaft | Dual Overhead Camshaft |
| Typical Power Output | 145-165 HP | 195-280 HP (stock) |
| Performance Potential | Moderate | Excellent |
| Common Applications | Early Galant, Eclipse | Lancer Evolution, Eclipse GSX |
| Maintenance Complexity | Lower | Higher |
| Tuning Popularity | Moderate | Very High |
Specifications and Maintenance of 4G63T Engine
| Specification | Details | Notes |
|---|---|---|
| Displacement | 1,997cc (2.0L) | Slightly larger than advertised 1.8L in some markets |
| Bore × Stroke | 85.0mm × 88.0mm | Slightly undersquare design |
| Configuration | Inline-4 (I4) | Cast iron block with aluminum head |
| Valvetrain | 16 Valves (4 per cylinder) | SOHC or DOHC depending on variant |
| Compression Ratio | 8.5:1 - 9.5:1 | Varies by specific model and year |
| Fuel System | Multi-point EFI | Electronic fuel injection |
| Turbocharger | TD05/TD04 (varies by model) | Factory turbocharger with intercooler |
| Power Output | 145-280 HP (stock) | Varies significantly by model and generation |
| Torque Output | 190-300 lb-ft (stock) | Varies by model and boost pressure |
Essential Maintenance Schedule
| Maintenance Task | Interval | Importance |
|---|---|---|
| Oil & Filter Change | 3,000-5,000 miles | Critical - Use synthetic 5W-30 or 10W-30 |
| Timing Belt Replacement | 60,000 miles | Critical - Interference engine |
| Spark Plug Replacement | 30,000 miles | High - Use OEM-spec plugs |
| Air Filter Replacement | 15,000 miles | Medium - More frequently in dusty conditions |
| Coolant Flush | 30,000 miles | High - Use proper antifreeze mixture |
| Valve Clearance Check | 30,000 miles | Medium - Adjust if necessary |
| Turbo Inspection | 30,000 miles | High - Check for shaft play and oil leaks |
| Fuel System Cleaning | 45,000 miles | Medium - Maintains injector performance |
Pro Tip: For 4G63T engines used in performance applications or that see track time, consider shortening maintenance intervals by 30-50%. The timing belt, in particular, should be replaced more frequently on heavily modified engines due to increased stress and heat.
Key Maintenance Considerations
- Oil Quality is Critical: The 4G63T's turbocharger puts additional demands on engine oil. Always use high-quality synthetic oil rated for turbocharged engines and never extend oil change intervals.
- Cooling System Integrity: These engines can run hot, especially in modified form. Regularly inspect all cooling system components and consider upgrading to a higher-capacity radiator for heavily modified engines.
- Timing Belt Vigilance: The 4G63T is an interference engine, meaning a timing belt failure can result in catastrophic valve and piston damage. Never delay timing belt replacement, and consider replacing the water pump and tensioners simultaneously.
- Turbocharger Care: Always allow the engine to idle for 30-60 seconds before shutdown to allow the turbocharger to cool down properly. This practice significantly extends turbo life by preventing oil coking in the bearings.
- Fuel System Maintenance: The high-performance nature of these engines demands clean fuel delivery. Use quality fuel with appropriate octane rating (91+ recommended) and consider periodic fuel injector cleaning.
Warning: Neglecting the timing belt replacement on a 4G63T engine can lead to catastrophic engine failure. The factory service interval is the maximum limit—consider early replacement, especially for modified engines or those used in harsh conditions.
How to Choose 4G63T Engines
Whether you're searching for a replacement engine or a performance upgrade for your project car, selecting the right 4G63T requires careful consideration of several key factors. This guide will help you navigate the market to find the optimal 4G63T for your specific needs.
Engine Condition Assessment
- Mileage Verification: Lower mileage engines (under 80,000 miles) typically command premium prices but offer better reliability potential.
- Compression Testing: Request compression test results showing balanced numbers across all cylinders (ideally 150+ PSI).
- Oil Analysis: If available, engine oil analysis reports can reveal internal wear conditions not visible externally.
- Visual Inspection: Check for oil leaks, particularly around the valve cover, oil pan, and turbo oil lines. Excessive external oil suggests poor maintenance.
- Coolant Contamination: Examine oil for milky appearance indicating potential head gasket issues.
Configuration and Generation
- Evolution vs. Non-Evo: Engines from Evolution models (especially Evo VIII and IX) feature stronger internals and better performance potential but command higher prices.
- JDM vs. USDM: Japanese Domestic Market (JDM) engines often have lower mileage and different specifications than US Domestic Market versions.
- Genesis Coupe Compatibility: Later 4G63T engines are not direct bolt-in replacements for earlier generations without modification.
- Forged vs. Cast Internals: Some variants (particularly from Evolution models) feature forged internals with significantly higher durability under stress.
- ECU Compatibility: Ensure the engine's management system will work with your intended vehicle platform or budget for standalone management.
| Selection Factor | What to Check | Importance Level |
|---|---|---|
| Completeness | Includes intake/exhaust manifolds, turbo, alternator, etc. | High - Complete engines save significant time and cost |
| Documentation | Service history, compression test, previous usage | High - Verifies condition claims |
| Modifications | Previously modified or stock configuration | Medium - Modifications can affect reliability |
| Source Reputation | Seller reviews, warranties offered, return policy | High - Protects investment |
| Compatibility | Specific to intended vehicle application | Critical - Ensures proper fitment |
| Price vs. Market | Compare to current market averages | Medium - Value assessment |
Expert Advice: When possible, opt for an engine sourced from a specialty importer or rebuilder who offers a warranty. The slight premium is often justified by the reduced risk and professional inspection these engines typically undergo.
Market Trends Affecting 4G63T Values
- Rising Collectibility: As Mitsubishi has discontinued the Evolution lineup, clean 4G63T engines are becoming increasingly valuable collector items.
- Modification Premium: Properly built 4G63T engines with quality aftermarket components often retain value better than stock engines with high mileage.
- Generational Differences: Later Evolution engines (VII-IX) command significant premiums over early non-Evolution variants due to stronger internals and higher tuning potential.
- Import Regulations: Changes in import rules affect the availability and cost of JDM engines, which can fluctuate market values significantly.
- Drift and Motorsport Popularity: The continued popularity of these engines in drift and time attack competition continues to drive demand and prices.
How to DIY and Replace 4G63T Engine
Safety Warning: Engine replacement is a complex procedure requiring specialized tools and mechanical knowledge. If you're uncertain about any aspect of this process, consult a professional mechanic. Always prioritize safety over saving money.
Required Tools and Equipment
- Socket and wrench set (metric)
- Torque wrench
- Engine hoist (cherry picker)
- Engine stand
- Floor jack and jack stands
- Transmission jack (helpful)
- Drain pans for fluids
- Penetrating oil
- Shop towels and degreaser
- Factory service manual (essential)
- Digital camera or smartphone (for documenting connections)
Time-Saving Tip: Before beginning, take detailed photos of all engine connections, wiring harnesses, and plumbing from multiple angles. This visual documentation will prove invaluable during reassembly, saving hours of confusion and potential mistakes.
Step-by-Step Replacement Guide
Preparation and Disconnection
Disconnect the battery (negative terminal first), drain all fluids (coolant, oil, power steering), and label all electrical connections before removal. Remove the hood for better access if possible.
Remove Accessory Components
Systematically remove the air intake, radiator, cooling fans, accessory belts, alternator, A/C compressor, power steering pump, and other external components. Keep fasteners organized in labeled bags.
Disconnect Drivetrain
Remove shifter linkage, clutch hydraulics, and driveshafts as applicable. Support the transmission with a jack before separating it from the engine.
Remove Exhaust and Intake
Disconnect the exhaust manifold/turbocharger assembly and intake manifold. Note the position of any brackets or heat shields for reinstallation.
Disconnect Engine Mounts
With all connections removed and the engine supported by the hoist, remove the engine mount bolts to free the engine from the vehicle's chassis.
Engine Extraction
Carefully lift the engine from the engine bay, paying close attention to clearance issues. Have an assistant guide the engine to prevent damage to surrounding components.
Prepare Replacement Engine
Transfer necessary components from the old engine to the new one (if not included), such as sensors, brackets, and accessories. Use new gaskets and seals where appropriate.
Install New Engine
Lower the prepared replacement engine into position, aligning it with the transmission input shaft and engine mounts. Secure the engine mounts and begin reconnecting components in reverse order of removal.
Refill Fluids and Initial Startup
Once all connections are secure, refill engine oil, coolant, and other fluids. Check for leaks, then attempt initial startup, monitoring for unusual noises or warning lights.
Final Checks and Test Drive
After confirming proper operation at idle, check for leaks again, then proceed with a careful test drive, starting with low speeds and gradually increasing load on the engine.
Important: Always follow proper torque specifications when reinstalling critical components, particularly engine mounts, main bearing caps, and cylinder head bolts. Improper torque can lead to engine damage or failure.
Alternative Options to Full Replacement
Engine Rebuild
Rather than replacing the entire engine, rebuilding your existing 4G63T can be cost-effective and allows for targeted upgrades. This involves disassembling the engine, replacing worn components, and reassembling with new bearings, seals, and gaskets.
Best when: Engine block and head are in good condition but internal components need replacement
Head Gasket/Partial Rebuild
If your 4G63T has head gasket issues or top-end problems but the bottom end is healthy, a partial rebuild focusing on the cylinder head can restore performance without the expense of a full engine replacement.
Best when: Compression issues are limited to the head gasket or valve train
Frequently Asked Questions
The power output of the 4G63T engine varies significantly depending on the specific configuration, model, and year. Stock naturally aspirated versions typically produce between 90-120 horsepower, while turbocharged variants generate 150-280 horsepower from the factory. The Evolution series engines are at the higher end of this spectrum, with later models (Evo VIII and IX) producing up to 280 horsepower in stock form. With aftermarket modifications, these engines are known to reliably produce 350-500+ horsepower with appropriate supporting upgrades.
The 4G63T engine is designed to run on premium unleaded gasoline. Mitsubishi recommends a minimum octane rating of 91 AKI (Anti-Knock Index) for stock engines, though many enthusiasts and modified engines benefit from higher octane fuels (93-94 AKI). Using lower octane fuel can cause detonation (engine knock), particularly under load or in hot conditions, which can damage the engine over time. Modern 4G63T engines are equipped with knock sensors that will retard timing if detonation is detected, but this comes at the cost of reduced performance and potentially increased fuel consumption.
The 4G63T engine code breaks down as follows:
- 4 - Indicates a four-cylinder engine configuration
- G - Represents the engine family/series designation within Mitsubishi's lineup
- 6 - Refers to the specific displacement/design revision within the G-series family
- 3 - Indicates the specific iteration or generation of this engine design
- T - Denotes that this variant is turbocharged (non-turbocharged versions are simply labeled 4G63)
This systematic naming convention helps identify the engine's core characteristics and differentiates it from other Mitsubishi powerplants.
With proper maintenance, a stock 4G63T engine can reliably achieve 150,000-200,000 miles before requiring major overhaul. These engines are known for their robust design and durability, particularly in stock form. However, several factors significantly impact longevity:
- Maintenance history (especially oil changes and timing belt replacement)
- Driving habits (hard acceleration, high RPM operation)
- Modification level (higher power outputs increase wear)
- Tuning quality (proper air-fuel ratios and timing)
- Environmental conditions (extreme temperatures, road salt exposure)
Modified engines typically have shorter lifespans proportional to how aggressively they're tuned and driven.
The 4G63T engine has become a popular swap candidate for various vehicles beyond its original applications. Common swap platforms include:
- Earlier Mitsubishi models (Starion, Galant, non-turbo Eclipse)
- Mitsubishi Mirage/Colt/Lancer chassis
- Dodge/Plymouth Colt and Eagle Talon
- Some RWD platforms with custom mounting solutions
Successful swaps require addressing several challenges including engine mounts, transmission compatibility, wiring harness adaptation, cooling system modifications, and ECU/engine management solutions. While not simple, the 4G63T's excellent power-to-weight ratio and proven reliability make it worth the effort for many enthusiasts.