Tuesday, 9 October 2012

SYSTEM OPERATION OF I-VTEC HONDA ENGINE




If you thought the normal VTEC was remarkable, i-VTEC will prove even more impressive! The ‘i’ brings to the VTEC concept "intelligent" combustion control technologies that optimize fuel economy, boast cleaner emissions and achieve higher performance. Incorporating VTC – Variable Timing Control – which continuously adjusts the intake valve timing to best match the current engine load, the driver enjoys abundant low-rpm torque, exhilarating high-rpm power and outstanding fuel efficiency.

With the i-VTEC system, there is a new camshaft to make it possible for continuously-variable camshaft phasing across the engine's entire power band. During typical operation, the intake camshaft timing is almost fully retarded at idle to help provide more stable idling while reducing exhaust emissions. As the engine speed increases, the intake camshaft is advanced, opening the intake valve sooner and providing additional valve overlap.

This results in increased fuel economy (by reducing pumping losses) and a further reduction in exhaust emissions (by creating a large, internal exhaust gas recirculation effect). Also, to generate additional power throughout the rev range, the intake camshaft is continuously varying the amount of advance or retard, adjusting in a split second to provide additional power when needed.

i-VTEC regulates the opening of air-fuel intake valves and exhaust valves in accordance with engine speeds

By regulating valve opening to match engine speed, the agile i-VTEC engine adjusts its characteristics to realize both superior power and low fuel consumption.
                         

Friday, 5 October 2012

Variable Cylinder Management (VCM), Honda latest technology

 


 
  Variable Cylinder Management (VCM) is Honda's term for a variable displacement technology. It uses the i-VTEC system to disable one bank of cylinders during specific driving conditions to save fuel. VCM uses a solenoid to unlock the cam followers on one bank from their respective rockers, so the cam follower floats freely while the valve springs keep the valves closed. The engine's drive by wire throttle allows the engine management computer to smooth out the engine's power delivery, making the system nearly imperceptible on some vehicles.

  The new mechanism debuted in 2003 with the V6 3.0-liter i-VTEC engine which used a new Variable Cylinder Management (VCM) technology that runs on six cylinders during acceleration but used only three cylinders during cruising and low engine loads. In 2005, Honda introduced the 1.8-liter i-VTEC engine for the Civic which could deliver accelerated performance equivalent to a 2.0-liter engine with fuel efficiency that is 6% better than the 1.7-liter Civic engine.

  Variable Cylinder Management (VCM) technology combines the excitement of a luxury vehicle's ample acceleration with outstanding fuel economy, enhancing both economic and environmental performances.The newly developed V6 engine with VCM technology gives you the best combination of outstanding power and unmatched fuel efficiency. Firing on all cylinders, this engine delivers superior performance. For moderate speed and climbing moderately inclined roads, the engine operates on four cylinders. During slow cruising and at low engine loads, the system idles on one bank of three cylinders, thus achieving outstanding fuel economy. 


VCM was materialised by combining Honda's original VTEC system with other advanced Honda technologies.  








Vehicles equipped with VCM
  • 2003 Honda Inspire
  • 2005-2007 Honda Accord Hybrid (JNA1)
  • 2005+ Honda Odyssey(USDM) EX-L and Touring Models only (J35)
  • 2006+ Honda Civic Hybrid
  • 2006+ Honda Pilot 2WD Models only (J35)
  • 2008 Honda Accord except EX-L V6 6MT Coupe
  • 2009+ Honda Pilot (all models)
  • 2010 Honda Accord V6 (except EX-L V6 6MT Coupe)
  • 2011-2012 Honda Odyssey (USDM) V6 (all models)

2.4 DOHC i-VTEC with Variable Cylinder Management(VCM)

 The advantages of the Variable Cylinder Management (VCM) are:
  • powerful engine
  • fuel efficient
  • lighter weight
  • produces lower emission