LTCev diagram *
The patented unequal volume closed-loop efficient indirect pneumatic coupling induction system & method of the LTCev can achieve Otto cycle I.C.E. higher fuel efficiency
at sustained useful engine loads of CAIC
(aka:throttled) Otto cycle S.I. engines and by being beneficial and is not only also compatible and with state of the art
direct fuel injection system for S.I. & D.I. UAIC
( aka:Direct fuel injection) liquid fuel controlled engines, it can significantly improve their specific fuel efficiency;

the LTCev is uniquely advantageously capable of neutralizing pumping-loss-friction and generate pumping-gain for all
LPG / CNG gaseous fuels controlled systems ( including
H2 hydrogen ) of all Otto cycle multiple reciprocating pistons engines.

unique "wet-sump /dry-sump" individually controlled  variable volume individual cylinder-crankcase configuration ( aka: VVICC ) providing ΔP indirect pneumatic-coupling turbo compound advantageously
providing affordable robust  CAIC aka: throttled Otto cycle multiple cylinders engines S.I.D.I.not only the possibility to reduce pumping-loss friction but also to provide it with  pumping-gain advantage ,
LTCev  can also provide even higher pumping-gain advantage to state of the art  C.I.D.I. UAIC Otto cycle engine to further enhance said engine's specific fuel efficiency
(without any increase of NOx emissions).

LTCev provides both pumping-loss neutralizing  capability and pumping-gain advantage for S.I. Otto CAIC robust engine strategy that is
compatible with both
liquid state fuel systems (gasoline/ethanol) but also various gaseous state fuels including compressed natural gas  (CNG)  methane, propane fueled  
and hydrogen *in Otto cycle reciprocating piston  engines; as well as providing advantageous pumping-gain enabling to eing capable to
further improve the fuel efficiency of  
 S.I. Otto cycle engine and also of UAIC  ( GDI direct fuel injection system ) engines

and to effectively challenge the experimental
DING natural gas engine project for cost effectiveness, flexibility, and reliability.

depending on the pre-determined specific Inverted Function Turbocharger's optimization:
  • LTCev  can  be optimized to cost effectively provide ΔP=0  beneficial neutralizing effect to pumping-loss friction of "throttled" engine
    (CAIC) controlled-air intake-cycle) as Gasoline Direct Fuel Injection system can do  to reduce part-load SPECIFIC FUEL CONSUMPTION
  • LTCev can be optimized to provide (CAIC) controlled-air intake-cycle)  intake cycle pumping-gain ΔP<0 assistance at higher engine load beneficial to all Otto cycle C.I. & S.I.
  • LTCev can advantageously use the ambient barometric air pressure energy exerted onto a piston crown during Otto intake cycle in conjunction with  the alternate under-pressure
  • created in a VVICC   ( individual cylinder crankcase) to allow turbo compound indirect pneumatic coupling provided by available ambient atmospheric pressure inside the cylinder.
  • LTCev is capable (due  to ΔP<0 air pressure ) to be optimized to provide intake-cycle pumping-gain assistance further ENHANCING fuel efficiency of state of the art
  • turbocharged  * UAIC (uncontrolled-air intake-cycle) "direct fuel injection system" S.I. & C.I. engines
  • and  can provide more than the limited pumping-gain provided by the *(S.I. Ford Ecoboost,  &  C.I. VW TDI engines )  that are possible only for a more modest intake cycle pumping-gain ΔP<0 assistance
at higher engine load because any direct pneumatic coupling pumping-gain  inevitably raises dynamic compression ratio, resulting in more  raw  NOx emission.

1- The S.I.  LTCev  ( CNAIC) engine (using liquid fuel) is provided with the capability to cost effectively challenge gasoline Otto cycle S.I.  UAIC strategy engine GDI stratified
direct fuel injection system's,GDI's fuel-efficiency and prior art CAIC strategy S.I. gasoline and ethanol engines.
2- An OttoCycle S.I.  LTCev  ( CNAIC) using gazeous fuel throttled engine can be provided with a significantly  part-load fuel efficiency improvement
that can effectively and significantly extend the range of prior art S.I. Otto cycle S.I. CNG and LPG gaseous fuel system CAIC strategy engines vehicles

The S.I.  LTCev provides higher part-load fuel efficiency, even with a simple, throttled ( CNAIC  strategy ) engine, that uses a stable, homogeneous charge intake cycle and
does not have to rely on the critical and technically demanding UAIC strategy engine (direct fuel injection system), that is a substantially more costly fuel system,
characterized by not requiring nor using any intake air control means (or throttle) for controlling engine power at part-load* ; direct fuel injection system is importantly
advantageous because it does not generate  detrimental intake-cycle pumping-loss friction.  Usual prior art Otto cycle CAIC strategy S.I. engine's fuel efficiency
is normally negatively affected by intake cycle pumping-loss friction at engine part-load.  Prior-art CAIC strategy engines ( throttled) suffer from increased
specific fuel consumption at engine part-load, ipso facto also increasing the emanation of GHG anthropogenic CO2 emissions.

* NOTE: part-load is the most prevalent and important engine operation range related to fuel efficiency affecting
personal transportation vehicle's operation, especially during long-distance cruising.

State of the art direct fuel injection system where is a fuel control system, where fuel only is controlled is a  UAIC strategy is applicable for both the Otto (S.I.)
(gasoline) engine and the Otto (C.I) (Diesel) engine.Indeed, UAIC strategy allows both the Otto cycle spark ignited (S.I.) and compression ignited (C.I.)engines
to be totally immune from detrimental pumping-loss friction at part-load.
The LTCev was originally devised as a robust, fail-safe, fuel efficient, CAIC lightweight engine strategy, providing a cost effective  alternative to direct fuel injection system
and is compatible with multiple cylinders light aircraft usual and reliable, CAIC strategy S.I.engine, while safely increasing the cruising range of said aircraft by reducing
engine's part-load specific fuel consumption. By neutralizing part-load engine pumping-loss- friction  and providing advantageous pumping-assistance at higher engine load,
It can achieve this task without needing to alter the robust and stable CAIC strategy stoichiometric air-fuel air-fuel mixture by leaning-out the engine's air-fuel mixture and
therefore always insure a desirable fail-safe combustion process, neither having to rely on engine downsizing-compromise; as this compromise necessitates intensive gearbox
ratio reduction for providing suitable propeller rotational speed and torque .

Suitably optimized LTCev can compare with direct fuel injection fuel efficiency in regards to pumping-loss elimination, without the main disadvantages of
high development and production cost, mainly due to the fact that LTCev is simple, robust and does not suffer from direct fuel injection's negative propensity to
accumulate disruptive intake valves carbon build-up as a result of frequent and sustained light load engine operation. Although new direct injection engine could
operate without suffering from part-load pumping-loss, even whitout downsizing engine displacement, downsizing compromise is still required for minimizing
the direct injection system's negative propensity to accumulate disruptive intake valves carbon build-up. Indeed, if said carbon build-up accumulation collects
mainly to backside of intake valve and remains unattended, it can seriously, negatively affects specific fuel consumption, reduce drive ability, ruin costly
exhaust emission system and significantly increase raw emissions levels.

Note:  The recent emergence of interest in the automotive industry for the engine downsizing-compromise is due to the fact that it is technically quite less costly
(but much less effective) to proportionally reduce pumping-loss friction, by using a smaller displacement engine operating at higher engine load and speed,
requiring a wider throttle opening compromise, than opting for substantially more costly and technically advanced state of the art UAIC direct fuel injection system;
since pumping-loss is directly proportional to engine displacement volume and also directly proportional to the severity of intake-cycle air-control CAIC
(by throttling or other means).

The displacement related pumping-loss friction explains the demise of previously, cost-effective and trouble-free but "inadequately fuel-efficient at engine part-load
" CAIC (throttled) prior art V-8 engines popular in earlier, larger, much heavier full size North American personal vehicles and medium duty trucks operating mainly
in an urban environment.

LTCev can provide higher fuel efficiency capability to robust low maintenance affordable S.I. Otto Cycle CAIC engine

The LTCev (CNAIC) effectively neutralizes said pumping-loss friction, without requiring any engine downsizing compromise (as direct fuel injection system do).
It is cost-effectively allowing, partial lowering of part-load specific fuel-consumption and proportionnally insures  a reduction of CO2 emission to the homogeneous-charge
affordable S.I. Otto "Controlled-Air Intake-Cycle" CAIC  strategy S.I. engine.

The LTCev neutralizes detrimental "engine displacement related pumping-loss friction to prevent usual  CAIC fuel efficiency reduction at engine part-load),
and does it  by conveniently and cost-effectively controlling both air and controlling fuel  to achieve a stable and tolerant robust combustion process without
altering homogeneous air-fuel charge and combustion process's stability, Direct fuel injection system being a significantly more sophisticated and more technically
demanding system fuel-controlled-only and that must cope with uncontrolled air intake cycle  is also critically limited by time for providing adequately critical mixing
and charging of the adequate homogeneous or stratified air/fuel-mixture process to provide adequate combustion of air-fuel charge mixture in the cylinder.

An innovative approach allows neutralizing engine part-load pumping loss friction of CAIC S.I. engine. It can be uniquely achieved by means of
strategic timely closed-loop pulsating pneumatic-coupling Δp = 0 turbo compound effects generated in unequal volumes individual cylinder crankcase.
Said Δp = 0 pressure condition being generated by an inverted function pulsating turbocharger* of the
Light Turbo Compound engine variant. *
( Canadian patent CA 2,732,477 )

Although engine downsizing can be of proportional assistance, to reduce part-load pumping-loss friction, it could be more effectively achieved only by
using a substantially, more costly, more technically demanding and critical fuel system such as: Otto " Uncontrolled-Air Intake-Cycle " ICUA strategy
charge direct fuel injection system.

Otto cycle UAIC engine stategy compromises:
Because the LTCev can be optimized to be virtually immune  (beyond idle)  from displacement-related pumping-loss friction at engine useful part-load,
undesirable usual CAIC Otto cycle S.I. engine downsizing remains possible but is NOT mandatory and
compromises 1 - 6  are no longer issues to contend with

one  significant undesirable UAIC issue of (direct fuel injection system)'s risk of intake valve carbon accumulation (compromise 7)
is not an issue for the LTCev.  and neither are the following points:

  • 1- higher fabrication cost due to downsized engine, higher MEP, higher RPM  and operating strain,
  • 2- mandatory downsized engine reduced operational engine flexibility3- inevitable higher NOx emission level,
  • 4- higher engine operating speed and narrower power band requiring multiples gear and gear changes,
  • 5- user perception, of affected engine longevity,
  • 6- narrower power band with lower low-end torque requiring extensive number of gear ratios.
  • 7- vulnerability of intake valve carbon accumulation  build-up following cumulative frequent  and sustained
  • low engine load operation,
  • and importantly not stricly adhered frequent and regular oil change schedule.     US patent 6866031 B2   VW

  • It is important to note that those compromises can now become unnecessary and can now be avoided without negatively affecting engine part-load
  • fuel efficiency and allowing to freely opt for the ideal required engine displacement size due to the new opportunity to use the light turbo compound engine
  • variant strategy for affordable personal extended range transportation vehicle.

Otto cycle  LTCev CNAIC engine strategy advantage:  By retaining the advantageous characteristics  of the affordable and widely popular
S.I. Otto cycle Controlled-Air Intake-Cycle  CAIC  engine"that provides stable and robust combustion characteristics due to stoichiometric air-fuel  
homogeneous intake-cycle charge mixture; CAIC  strategy's simplicity, reliability and flexibility can now be advantageously complemented with
a significant part-load improvement of  fuel-efficiency which furthermore only requires less critical, proven, efficient and affordable fuel control system.
Since the most prevalent and useful engine operating range of any Otto cycle engine for personal transportation occurs at engine part-load, the LTCev is ideally suitable
for reducing dependency of fossil fuel for extended range personal vehicles and as well as electric hybrid and mild hybrid vehicles

  • 1  MINIMAL NEGATIVE HOLISTIC ENVIRONMENTAL IMPACT:  minimal contributing GHG CO2 emissions, HC & NOx emissions

  • 2  HIGH FUEL EFFICIENCY:  focus on extended range personal vehicle utilisation (using fossil, renewable bio-fuel and gaseous fuel )

  • 3  COMPATIBILITY: with existing and proven state of the art Otto cycle technologies & alternate fuels insures cost-effectiveness
  • retrofit and reliability

  • 4  Pumping-Gain Assistance-Capability: conveniently provided by available ambient atmospheric* pressure assistance (P2)
    to provide a ΔP condition where  Δp< 0 such that at higher engine CAIC operating loads Δp < 0 results in beneficial
    pumping-assistance capability to further improve specific fuel efficiency without inevitably increasing NOx emission.
  • 5 LTCev CAIC engines can be more robust (less vulnerable to deposit of carbon on intake valve) than GDI system (UAIC strategy)

The LTCev can prove useful to rationalize
cost for manufacturing flexible and fuel
efficient  Otto cycle I.C.E. components for
electric hybrids  and for extended range
vehicle's engine; simultaneously capable
of lowering raw NOx and HC emissions, as
well as lowering CO2 emissions.
Unique's LTCev's " Higher supplemental " pumping-gain assistance capability when
used with
can be be used to further improve  turbocharged/ direct fuel injected intake cycle pumping-gain advantage
of UAIC existing engines such as:
Ford's EcoBoost S.I. engines or VW TDI C.I.engine,
but can further improve their fuel efficiency and reduce CO2
not increasing their NOx emission.

CAIC Spark Ignited (S.I.) Otto Cycle throttled internal combustion engines
suffer from parasitic
pumping losses associated with partial vacuums developed in
their intake manifolds and in the cylinders above their pistons,
as is illustrated in fig. pv8AA.dwg .      
This drawback is most prevalent when a S.I. Otto cycle engine is operated at
part-load with the throttle partially closed. During each intake cycle of of a throttled
Otto S.I. engine  
CAIC  (controlled air intake cycle); operating at part-load, extra
pumping work must be done by the piston as it draws the air-fuel
mixture from the intake manifold into the volume expanding cylinder to counteract a
force on the opposing face of the piston due to a pressure imbalance intake
delta P
existing in the cylinder volume above the piston versus near atmospheric pressure
in the crankcase volume below the piston. This extra work negatively affects the
engine’s specific fuel consumption and its level of anthropogenic emission and is the
major drawback for vehicles requiring the use of larger displacement throttled
engines in extended range operations and in engine applications requiring a wide flat
responsive power curve
Eliminating part-load pumping-loss friction is an important  Otto cycle fuel
efficiency advantage
that could previously mainly only be best provided
UAIC direct fuel injection system see: (fig.pv8AB.dwg)
hic inceptant futura

Light Turbo Compound unique closed-loop-ΔP pneumatic coupling can uniquely  match UAIC strategy (direct fuel injection)
engine intake cycle efficiency at part-load by eliminating Otto intake cycle pumping-loss friction of throttled
lagom* engine
CAIC strategy), adequately using an inverted- function-turbo charger providing more Intake cycle Pumping-gain at higher
engine loads and can cost effectively challenge turbo-charged and direct fuel injection system engine such as
John B. Haywood's
group's (Ford's S.I. Ecoboost engine) that uses both a usual function turbocharger and GDI at higher engine loads BMEP,
but unlike the Ford ecoboost , LTCev engine can do so without simultaneously
increasing said engines's raw NOx emission.
LTCev's IFT* can neutralize pumping-loss Otto cycle CAIC (throttled) engine usual for homogeneously charged lean-burn gas engines emulating
liquid-fuell engine using
GDI:Gasoline ( AKA Direct fuel Injection system's) : capable to neutralize pumping-loss-friction 2* that negatively affect
specific fuel consumption and ipso-facto GWG emissions but
without further increasing NOx emissions while also providing some additional
pumping- gain assistance
*3 to  S.I. Otto cycle UAIC ( Direct Fuel Injection liquid fuel Gasoline engines.
site copyright
NOTE: as UAIC's GDI (direct fuel injection system) adequately controls pumping-loss-friction
of liquid-phase-fuels: (ie.gasoline)
LTCev controls pumping-loss friction of gaseous phase fuel: (ei. Natural Gas CH4)
state of the art
of  NGV's compressed natural gas fuel
 controlled by
throttled gaseous fuel control system systems  
LTCev 2.3A.dwg
gaseous state fuel systems
unique advantageous compatibility

of IL4 Firing  Order 1-3-4-2  
makes it easier to envision
the alternately contracting /
expanding VVICC's volume  
Light Turbo Compound engine variant:   LTCev 1 & 2