What is the 4G63?

One of the greatest four cylinder engines to ever leave Japanese shores, the 4G63 is a powerhouse of a performer. Capable of reaching well into the 400 horsepower range bone stock, the 4G63 elevated the Mitsubishi Evolution as one of the great Japanese sports cars. These engines were also found in USDM vehicles under the banner of Diamond Star Motors or DSM.

DSM’s enjoyed a brief run in the mid 90s as an affordable turbocharged all-wheel drive sports coupe. Before the Evolution and WRX arrived stateside, the Mitsubishi Eclipse, Eagle Talon and Plymouth Laser battled it out for turbo AWD glory.

 

Diamond Star Motors gave birth to the 1989-1994 first generation and 1995-1999 second generation of sports coupes, with several different versions of the 4G63. What most enthusiasts know as the 4G63 is actually called the 4G63T, which is the turbocharged 2.0 liter DOHC engine from Mitsubishi.

The 4G63 also came in normally aspirated trims, from the 2.0 liter non turbo 4G63, as well as the variant in the 1.8 liter 4G93. Mitsubishi Eclipse RS, GS models came with the non turbo 4G63 in the first generation, which was replaced with the 420A in the second generation Eclipse. This engine follows the same Mitsubishi nomenclature when it comes to the engine code.

• The first digit of the Mitsubishi engine code signifies the number of cylinders
• The second is the fuel type
• The third is engine family
• The fourth is model

The 4G63 then is a gasoline powered four cylinder engine that also came in the Evolution until the Evolution X. Sadly the 4G63 is also known for another remarkable trait, which is crankwalk. Crankwalk is when your crankshaft moves inside your engine block, whether from a failed thrust bearing or mis-machined engine girdles, the outcome is the same.

 

The first signs of crankwalk can occur when your DSM or Mitsubishi shuts off during left hand turns. At advanced stages, you can hear the crank actually turning and clipping your crank position sensor as you depress your clutch. Needless to say, if you have crankwalk, you need another complete engine to replace your old one.

Without a bit of hyperbole, crankwalk is probably the reason Mitsubishi pulled the plug on the Evolution. At a time when the Evolution, who should be enjoying similar success as the Subaru WRX and STI, is nearing it’s production run only underlies the huge reliability problems Mitsubishi had. Instead of standing up and taking accountability, Mitsubishi shirked away from crankwalk which led to a huge scandal that nearly toppled the Japanese automaker.

 

There’s two different variations of the 4G63T and you can tell them apart from how many holes are in their crank snout. Older six bolt engines had some differences over their seven bolt cousins, things like larger rods for pre-92 engines gave earlier six bolt engines the nod for most modders. Which is why engine swapping to a six bolt motor is so common and popular among the DSM crowd.

 

 

If you are planning a 1G six bolt 4G63 swap into your chassis, it’s always a good idea to look into 1G cam angle sensors. Certain cam angle sensors from the first generation Eclipse allow you to adjust base timing, a very handy tool for any turbocharged tuner.

Whatever the reason behind you learning what the 4G63 is, there’s no doubting it’s power and robust nature. Coupled with just a few fuel upgrades and a tuning computer that’s capable of manipulating KARMAN air flow signals to adjust fuel, the 4G63 is as good as any four cylinder engine.

This DOHC engine is certainly a powerful performer and easily one of the best bang for your buck engines out there. Upping the boost in your turbocharged engine is easy to do, and paired with the right amount of tuning can elevate horsepower and torque exponentially.