The Mitsubishi 4G9x Engine Guide!

[Morpheus23]

The Mitsubishi 4G9x Engine Guide.
1.5 to 2-litre fours with the technology of MIVEC, cylinder deactivation, GDI and turbocharging...

No other engine series showcases Mitsubishi�s technological development more than the
4G9x four-cylinder. In this article we take an in-depth look at these wonderful engines
that range from 1.5 to 2 litres capacity and are available with MIVEC variable valve timing
and lift, cylinder deactivation, turbocharging and GDI direct injection...

Mitsubishi 4G9x Engines:

The Early 4G91:

The first in the range of Mitsubishi 4G9x engines is the 4G91 which uses a 78.4mm bore and
77.5mm stroke for a total displacement of 1.5 litres. With a 9.5:1 compression ratio and
DOHC, four-valve-per-cylinder head and multi-point EFI, this engine puts out a creditable
84kW at 6000 rpm and 135Nm at 5000 rpm on normal unleaded fuel. The engine can be
found in the Japanese market �91 top-line Lancer and Mirage/Mirage Asti.

A low output carby version was also produced but it�s not likely you�re interested in that...
Both engines are designed for transverse mounting and are available with a four-speed auto
or five-speed manual �box.
Most examples are front-wheel-drive but, curiously, an all-wheel-drive carby version was
also produced. This engine lasted only until the mid �90s.

More Cubes and MIVEC/MIVEC-MD

Based on the original 4G91 1.5-litre engine is the 4G92 1.6-litre which appeared from late
1991. The 4G92 achieves its extra capacity thanks to a slightly larger 81mm bore and
released in the late 1991 Japanese spec Mirage RS and Super R (later known as the Mirage R),
it is quite highly tuned.

With an 11:1 compression ratio necessitating the use of premium unleaded, the DOHC 4G92
generates a healthy 107kW at 7000 rpm and 149Nm at 4500 rpm. This engine is available in
manual or auto, FWD or AWD. Production of this engine ended in around 1993, but that�s no
great loss given its long-term replacement � the firecracker 4G92 MIVEC!

One of the most powerful Mitsubishi atmo fours (and one of our all-time favourites) is the
4G92 MIVEC as found in the Japanese market �92 Lancer MR, Mirage Cyborg/VR and
hi-po post-�94 Mirage Asti models. This wonderful little engine employs an 11:1 compression
ratio and benefits from MIVEC variable valve timing and lift.
Output is a VTEC-whipping 129kW at 7500 rpm and 167Nm at 7000 rpm - as you can probably
tell, this is an engine that loves to rev!



The 4G92 MIVEC engine is available with a five-speed manual or a four-speed auto
(with Sports Mode sequential shift from late 1995). Drive is to the front wheels only.
Interestingly, a Modular Displacement (MD) version of the 4G92 MIVEC was also produced �
MD is Mitsubishi�s cylinder deactivation system which helps improve fuel consumption.
It appears this option was available for only a few years.
The conventional 4G92 MIVEC was manufactured until around 2000.



Check the full article here... Link--> The Mitsubishi 4G9x Engine Guide!
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[Sanctifier]

Good link Morpheus. Very informative article. Thanks a lot.

Now 4G9x fans can use this thread as a ~ Tech Archive & On-line Resource for
Specifications... Technical data... and Tuning & Maintenance Tips for this engine.

Thanks again.
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Walk softly... and carry a BIG stick!

[Morpheus23]

No problem Sanctifier. Remember it's based on your recommendation that I post this here too.


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I am a Sohhhcah Warrior!!!

[Greypatch]

excellent
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Handle every situation like a dog...If you can't Eat it or Screw it.
Piss on it and Walk Away