From industrial giant to rally legend
Mitsubishi built just about everything before it built fast cars: ships, aircraft, rail equipment, forklifts, generators, even air conditioners. The company only dipped a toe into motorsport in the 1960s. It was the 1980s, with a factory World Rally Championship program, that put it on every enthusiast's radar, and the engine at the center of that story was the 4G63.
A short history
The 4G63 belongs to Mitsubishi's Sirius (4G6) family. It arrived in 1980 as a naturally aspirated 2.0 liter four. The version enthusiasts care about is the turbocharged 4G63T, which first showed up in the 1988 Galant VR-4 and later became the heart of the Lancer Evolution.
US buyers mostly know it from the Diamond Star Motors cars, the "DSMs." These were sport compact coupes sold under the Mitsubishi, Eagle and Plymouth brands, and the upper trims of the first and second generations got the turbo 4G63.
The competition record
- Late 1980s: the Group A Galant VR-4 delivered Mitsubishi's first outright WRC wins.
- 1996 to 1999: Tommi Mäkinen took four straight drivers' titles in the Group A Lancer Evolution, and Mitsubishi won the manufacturers' championship in 1998.
- 1995 to 2001: the Evo won seven Group N (showroom class) titles in a row with four different drivers.
- 2002: Mitsubishi finished second in Group N to Proton, whose winning car was itself powered by a 4G63.
Rally and circuit racing made its name, but over roughly the last fifteen years drag racing has become just as important to the 4G63 story. In the US, builders like David Buschur and John Shepherd pushed DSMs down the quarter mile, and racers such as Aaron Gregory and Devin Schultz have carried that on with cars running consistent 7- and 8-second passes at over 200 mph. Records keep falling, which is remarkable for a four-cylinder that started life in family sedans.
What's inside
| Part | What you get |
|---|---|
| Block | Cast iron |
| Cylinder head | Aluminum |
| Crankshaft and rods | Forged steel |
| Pistons | Cast aluminum |
| Cam drive | Timing belt, not a chain |
Heads vary by version. There's an 8-valve single cam head at the bottom of the range, a 16-valve single cam head in the middle, and the 16-valve twin cam head at the top, which itself comes in big port and small port versions. The single cam heads use rocker arms with manually adjusted valve lash. The twin cam heads, available since 1987, also use rockers but with hydraulic lash adjusters, so there's no clearance setting to worry about.
Like Honda's B and K series, the 4G63 shares its head and block architecture with a longer-stroke sibling, the 4G64. Mixing parts between the two is a well-known route to more displacement, up to around 2.4 liters.
The design has been in production in one form or another for about 40 years, and aftermarket support is as strong as ever. That combination of a tough iron block, a head that flows well, and a deep parts catalog is why well-built examples make over 1,000 horsepower, and billet-block engines have reached as much as 1,700 hp.
What to watch out for
6-bolt versus 7-bolt
The name refers to how many bolts hold the flywheel to the crank, but the difference runs deeper than that. The 7-bolt engines use narrower main bearing journals, and many builders consider them the weaker choice for big power, so 6-bolt blocks tend to be more sought after.
Crank walk
The 7-bolt engine also has a reputation for "crank walk," where the thrust bearing wears out quickly and the crank starts moving fore and aft, which ends badly for the bottom end. It's a hotly debated topic, and plenty of people argue the 7-bolt isn't really more prone to it than any other engine. Either way, the lesson for buyers is the same: before you hand over money for a used 4G63, check the crank for end play. Excess movement is an early warning of a tired thrust bearing.
The balance shaft belt
From the factory, a second, smaller belt at the back drives balance shafts. If that belt breaks it can take out the main timing belt, and on an interference engine that means serious damage. That's why deleting the balance shafts and their belt is one of the first jobs on most performance builds. The only real cost is a bit more vibration at idle and cruise, which most owners happily accept.
Running a 4G63 on Haltech
Haltech ECUs support every factory 4G63 trigger pattern, from Evo 1 through Evo 9 and both 1G and 2G DSM, along with the popular aftermarket crank and cam trigger setups. Our 4G63 trigger page covers the settings, and the 4G63 engine page has sensor and wiring details.
How you wire it depends on the car:
- Evo, keeping the factory loom: Elite plug-in systems such as the Elite 1500 for Evo 4 to 8 (5-speed) or the Elite 2500 for Evo 9 and Evo 8 MR.
- Earlier Evos: the Evo 1 to 3 plug-n-play adaptor lets an Elite connect to the factory harness.
- Galant VR-4 and 1G Eclipse: the Elite 1500 kit for Galant VR-4 and 1G Eclipse.
- Swaps and full rewires: Haltech also makes terminated engine harnesses for 1G and 2G DSM layouts, or you can wire a universal Elite or Nexus ECU from scratch.
If you're not sure which route suits your car, see how plug-n-play adaptor harnesses work, or browse the Haltech range.
Check crank end play, confirm whether the balance shafts are still in and when the belts were last done, and verify which trigger setup the engine actually has. Engines get swapped between chassis a lot, and the trigger doesn't always match the car it's sitting in.
4G63 FAQ
Is a 6-bolt 4G63 really stronger than a 7-bolt?
The 6-bolt has wider main journals and is generally preferred for high-power builds. A healthy, well-built 7-bolt can still make big power, but check it carefully for crank end play first.
Should I delete the balance shafts?
On a performance build, most people do, because a failed balance shaft belt can destroy the engine. You'll feel slightly more vibration at idle and cruise.
Can Haltech run my aftermarket 4G63 trigger kit?
The popular aftermarket crank and cam pickups are supported. Tell us which one you have and we'll confirm the setup. Book a free 30-minute consultation to talk through your build.
