This document discusses a proposed mechanism to provide variable compression ratio and cylinder deactivation in engines. The mechanism uses a four-bar link design modeled in Creo software. Simulation results show the design can deliver more uniform torque across engine speeds by varying the compression ratio to match load conditions. It can improve fuel efficiency up to 30% by allowing cylinder deactivation under light loads. The novel mechanism was modeled and theoretically shown to enhance torque and power across a wider speed range while reducing fuel consumption.

1. ABSTRACT
There is customer demand for a vehicle that is having good power, torque and
better fuel economy through the speed range range of the vehicle and an implied
environmental need ofimproved emission characteristics. There are various ways
to improve the performance of the engine some of which are; super charging,
turbo charging, variable compression ratio (VCR), variable intake system
geometry, variable valve timing and lift (VVT) etc. In this project we have
concentrated on variable compression ratio and cylinder deactivation.
Engine demands variable compression stroke at different speed and load for
uniform Torque Development. This works presents a model of new mechanism
using software PTC Creo. This model facilitates variation in compression ratio
and cylinder deactivation of inline multi cylinder engine which is a 3 cylinder
engine and required modifications in it to accommodate this novel mechanism.
This mechanism is simple in construction and design, easy to manufacture, cost
effective and compact to accommodate in the exiting engines to facilitate the
variable compression ratio with cylinder deactivation.
This mechanism help the engine deliver uniform torque at different speed zones
by varying the compression ratio with respect to speed and load on the engine
while dividing the engine in two zones, low speed with high load and high speed
with low load condition. In this project author has concentrated on varying the
compressionratio and cylinder deactivation. Four bar link mechanism is used to
achieve the variable compression ratio and cylinder deactivation as per the need
ofapplication. Different compressionratios are designed that they give maximum
uniform torque and power at particular speed zone compared to the base engine
with fixed compression ratio. This mechanism is designed using PTC Creo
modelling software to find the best suitable and compactdesign for operating on
different zones of the engine i.e. the low speed with high load and the high speed
with low load. From design simulation we achieved best suitable and compact
mechanism which works to provide variable compression with Atkinson effect.
The modelled mechanism have shown the average increment of power and
suction stroke and decrement in compression and exhaust stroke by 22.2 % with
reduction of frictional losses of piston by 5.4% in case of cylinder deactivation,
Fuel efficiency can be improved up to 30% with considering ideal conditions.
The novel mechanism has been modelled and theoretically shown to give
improvement in torqueand powerboostthroughoutthe wider range ofproduction
engine with reduced fuel consumption.