The Mitsubishi 4G64 engine belongs to the Sirius Family with 4G63, 4G63T, 4G61, 4G62, 4G67, 4G69, 4D65, and 4D68. It was debuted in 1989 for Fifth-Generation Mitsubishi Galant. It is also a quarter of Mitsubishi’s four series of inline-four automobile engines and Orion, Astron, and Saturn.
4G64 engines are produced in Shenyang, China, by Shenyang Aerospace Mitsubishi Motors Engine Manufacturing (SAME) and assembled through semi-knockdowns in August 1998 and September 1999 for complete knockdown kits. The regular assembly took place in April 2000.
Since its production in 2003, 4G69 engines succeeded the 4G64s. However, 4G64s are famous in China and are still produced even up to this day, mainly for the Chinese market.
In the Chinese market, 4G64s are still used in Changfeng Liebao since 2002, cars based on Mitsubishi Pajero V20, and Soueast Delica based on Mitsubishi Delica van from 1996 to 2013.
So, let’s get right to it.
Here are some pieces of information that can help you wade through our 4G64 acquaintance:
Engine Specifications and Design
- Production Run: 1983 – 2003, 1983 – Present (China)
- Cylinder Head Material: Aluminum
- Cylinder Block Material: Cast-iron
- Configuration: Inline-four
- Bore: 86.5 mm
- Stroke: 100 mm
- Valvetrain: 8-valve SOHC (earlier models), 16-valve SOHC, and DOHC (Later on)
- Displacement: 2.4 L
- Compression Ratio: 8.5 (SOHC 8-valve head) 9.5 (SOHC 16-valve)
- Weight: 330 lbs.
- Max HP: 150 hp at 5,500 RPM
- Max Torque: 133 lb-ft at 3,500 RPM
Mitsubishi 4G64 engines and 4G63 engines are congruent with each other. 4G64 Is the second-largest variant which has a 2.4 Liter displacement that eventually replaced the previous 4G54. 4G64s are based on 4G63s for they have the same castings, and both are closed-deck engines; both are used in modern EVOs and carry the same materials for their engine block and heads. However, 4G64 engines have a taller block height by 6 mm, a larger bore with a 1.5 mm increase, and 4G64s have no oil jets for the pistons.
Inside the block, Mitsubishi installed a 100-mm long-stroke crankshaft, adjusted the deck height to 235 mm. Cylinder diameter or bore is also increased from 85mm of the 4G63 to 86.5 mm in 4G64s, and the length of the connecting rods stood at 150 mm. This engine has balance shafts with 35 mm compression height for pistons. Its crankshaft weighs 34.83 lbs, 0.78 lbs for pistons, and 1.37 lbs. for connecting rods. However, Chrysler versions feature fracture-split forged powder metal connecting rods.
4G64’s engine block was covered with a SOHC 8-valve head (non-interference engines )in its early releases, but 16-valve SOHC and DOHC were also produced later on, which are interference engines. All 4G64 variants used MPFI (Multi-Point Fuel Injection) and subsequently became available with Gasoline Direct Injection. LPG version was released in March 1996 to cater to the Mitsubishi Canter, and that version can produce 115 hp at 5,000 RPM.
4G64 outputs vary depending on the application. For Mitsubishi L200, it can produce 155 hp at 5,250 RPM and 163 lb-ft of torque at 4,000 RPM, while for the Chrysler Sebring/Stratus version, it can produce 152 hp at 5,500 RPM and 163 lb-ft of torque at 4,000 RPM. The turbocharged version of the 4G64 is 4G64T.
- 1983 – 1992 Dodge Colt Vista (All Wheel Drive Only)
- 1986 – 1998 Hyundai Grandeur
- 1986 – 2005 Mitsubishi Triton
- 1987 – 1990 Mitsubishi Sapporo
- 1988 – 2006 Mitsubishi Delica
- 1989 – 1991 Hyundai Sonata
- 1990 – Present Mitsubishi L200
- 1990 – 1992 Dodge Ram 50
- 1990 – 1996 Mitsubishi Mighty Max
- 1993 – 1997 Mitsubishi Chariot
- 1993 – 2003 Mitsubishi Space Wagon
- 1996 – 1999 Mitsubishi Eclipse
- 1996 – 1998 Mitsubishi Magna
- 1997 – 1999 Mitsubishi Montero Sport (ES North America)
- 1998 – 2005 Mitsubishi Montero (V11 2-door, South America)
- 1998 – 2003 Mitsubishi Space Wagon
- 1999 – 2005 Hyundai Sonata
- 2000 – 2005 Kia Optima
- 2000 – 2005 Mitsubishi Eclipse
- 2001 – 2004 Dodge Stratus Coupe
- 2001 – 2006 Hyundai Santa Fe
- 2001 Mitsubishi Airtrek
- 2002 – Present Changfeng Liebao (Mitsubishi Pajero V20 from China)
- 2003 – 2006 Kia Sorento 2.4i
- 2003 Mitsubishi Outlander
- 2004 Brilliance BS6
- 2004 – 2006 Chery Eastar
- 2004 – 2015 Hyundai Terracan
- 2005 – 2009 Mitsubishi Zinger
- 2007 Landwind X6
- 2008 – 2015 Chery V5
Engine Upgrades, Tuning, and Modifications
If you choose to ditch turbos, you might need to get a G4JS DOHC head along with its entire intake and exhaust system. G4JS is installed in 2000 – 2005 Hyundai Santa Fe, 2000 – 2009 Kia Sorento, and 2000 – 2005 Kia Optima. G4Js is the analog of 4G64.
You might also need to buy a cold air intake, an EVO Throttle body, camshafts, cam gears, valve springs, fuel rail, and 450 cc fuel injectors. Replace with a more powerful fuel pump, remove the balance shafts, and buy forged internals to increase the compression ratio to 11.5 and this will give you a 200 hp boost.
For turbos, you will need performance parts, of course. There are two options: 4G64 SOHC Turbo or 4G64+4G63 Turbo.
For 4G64 SOHC, you just need your stock engine and install an EVO turbo. You need to buy an EVO turbocharger, EVO header, EVO intercooler and pipes, EVO fuel pump, 560 cc fuel injectors, and a large radiator. Also, make sure to configure the ECU for these upgrades to work.
But suppose you are still not satisfied and still looking for “serious” power. In that case, you may consider 4G64 with an EVO head and all of its equipment such as 150-mm connecting rods, forged pistons, EVO intake system, EVO spark plugs, EVO ignition coils, EVO turbo, and headers. You also need to use 750cc fuel injectors and a 3-inch exhaust system. This can give you a faster spool than 4G63s and 400 hp at the crankshaft.
You can push it further than 400 hp, but you will need: cold air intake, larger radiator, intercooler and pipes, AMS intake manifold, valve springs and retainers, Aeromotive fuel rail and fuel pressure regulator, 1,000 cc fuel injectors, install oil jets in the cylinder block, remove the balance shafts, and an EVO turbo. This will give you 500 hp at the crankshaft.
Destrokers gives a high rod to stroke ratio that also contributes to engines’ capability to reach high revs, which 4G64s are not famous for. However, displacement is reduced due to the use of longer rods and short-stroke camshafts. This can be made by having the 4G64 block with a 4G63 that results in a 2.1 displacement which is suitable for high rev and attains high power output. For your destroker kit, you need some EVO crank with 88 mm stroke, ACL bearings, 156-mm connecting rods, and installation of oil jets in the block.
Problems Surrounding 4G64 Engines:
4G64s are identical to 4G63s, so they share many things, including premature wear, issues, and problems. These are some observations and preventive cautions to watch in your 4G64 engine:
First is too much vibration most commonly occurs on the left-hand side of the engine. This problem is quite ordinary and can be easily solved by replacing engine mounts when you notice any vibrations.
Next is the problem with balance shafts. The balance shaft aims to reduce the vibration caused by rotations by canceling out unbalanced dynamic forces. This is due to poor engine oil choices resulting in an increased risk of insufficient oil flow to the bearings, leading to shaft jamming and eventual timing belt breakage. You can solve this by using high-quality engine oil and regularly changing the balancing shafts belt. To add to that, poor engine oil quality is also detrimental for your hydraulic lifters that may prematurely ruin its service life.
Rough Idling. Rough idle is a result of collective neglect like dirty throttles, fuel injectors, ECT sensors, and idle control valves. Regularly check if they needed to be replaced, and clean these guys so rough idling will not occur again and again.
All 4G64 heads are hydraulically lifted, so you don’t have to worry about adjusting the valves. However, timing belts are used in the Sirius Family of engines and need to be replaced at least every 60,000 miles.
Mitsubishi 4G64 engines are reliable, especially if they are well-maintained and properly taken care of, such as using high-quality engine oils; regular engine check and observing any strange noise can come a long way. It can serve you for more than 250,00 miles and has no major or big issue haunting this engine. Just some replacements and learning how to get along with 4G64’s ups and downs, just like everyday things, then you are fine. Anyway, 4G64s is a legendary engine and one for the ages.
I hope that we cleared some clouds and confusion going in your head regarding Mitsubishi 4G64 engines. Whether you own one or planning to buy, I hope this little guide sorts out some things such as problems, issues, attributes, and maintenance.