From http://www.autoweb.com.au/start_15/showall_/id_VOL/doc_vlv0005023/article.html:

“Volvo Car Corporation is currently upgrading its engines. The upgrades, to RN (Revised N) status will take place successively and are already complete for the normally-aspirated V70 20v and light pressure turbocharged V70 2.4T.

Important technological solutions contribute to improving the RN engines.

 Lighter crankshaft and reduced running friction result in improved torque and quieter running.

 Advances is combustion technology result in lower fuel consumption and better throttle response.

Variable Valve Timing

CVVT technology (Continuous Variable Valve Timing) means greater low-rev torque and lower fuel consumption. CVVT is introduced on the V70 2.4T and T5 engines.

On the naturally-aspirated engine, CVVT alters the intake cam, and on the turbocharged engines CVVT alters the exhaust cam. CVVT can alter cam timing by as much as 20 degrees.

By altering the cam timing, the engine is able to produce better power response through a wider operating range. In other words, CVVT produces a wider powerband.

CVVT also reduces emission by controlling cylinder fill at low revs and providing maximum cylinder fill at high revs.

Less mass, less internal friction

Many of the reciprocating parts in the RN engine have been reduced in mass and size. For example, pistons, gudgeon pins and crankshaft counterweights are smaller and lighter, thereby reducing movement mass in the engine by about 25 percent or between 3.5kg and 4.5kg, depending on engine variant.

The RN engines use a short skirted piston with the gudgeon pin located nearer to the ring pack to allow the use of a longer connecting rod. A longer connecting rod is beneficial for several reasons. A longer rod reduces piston-to-bore friction, and improves efficiency and combustion by holding the piston at TDC for longer duration. At BDC a longer connecting rod promotes better cylinder fill, and finally, a longer connecting rod produces better torque by providing a better mechanical advantage.

Performance is improved while noise level and fuel consumption are reduced.

At the introduction of the new Volvo V70, only the 2.4-litre V70 2.4T light-pressure turbocharged engine has been revised. Compared to the N engine, the new 2.4T RN engine produces 5kW and 15Nm better performance.

The high-pressure turbocharged T5 engine will be revised in the near future.”

Does anyone know from what “engine serial number” the production of the T5 “Revised N” engine starts?

Perhaps there is a distinctive mark on the V70 T5 “Revised N” engine?

Rale