The invention hereby described is referring to an Internal Combustion Engine (ICE) with fuel intake and exhaust gas system according to the main concept of invention’s claim 1 .

In conventional ICE operating according to i.e., Otto cycle, fuel inlet and exhaust outlet in the combustion chamber is realized by the utilization of a cylinder head equipped with overhead valvetrain (intake and exhaust valves). These valves are mechanically controlled by a complicated arrangement which involve control keys, bridges, springs, pushrods, rocker arms etc., a complicated overhead valve (OHV), driven by one or more camshafts so as to provide the filling of the combustion chamber with mixture at the right time of the combustion phase and the purge of the exhaust gases during the end of the cycle. This arrangement has several drawbacks such as:

• a large number of moving parts (valve train) followed by the associated complexity, operating & maintenance (O&M) cost, poor reliability, noise, need for space etc.

• due to deposits, material failure, recession of valve in its seat etc. valves are often burned - particularly the exhaust valves (torched valve) resulting to the need to remove the cylinder head

• the existence of cylinder head at the top of the combustion chamber and the irregularities and discontinuities of its surface due to the intake / exhaust valves create potential ground for deposits and the consequent formation of uncontrolled combustion (knocking) during operation, thus reducing engine performance and life expectancy or even leading to its premature wear and destruction.

• due to the great strain into the combustion chamber, valves recession is taking place leading eventually to the need to remove the cylinder head.

• the installation of a cylinder head at the top of the combustion chamber results to insufficient cooling of the piston exactly at the point where the higher temperatures / stresses are exerted (at the piston crown).

The purpose of the invention described below is to eliminate these problems, while, at the same time, retain the essential advantages of ICE. By the features mentioned in claim 1 of current invention, the disadvantages mentioned above are removed.

The invention resuits to a modified ICE in which the conventional cylinder head with its associated intake / exhaust valves and the relevant control arrangement (push rods, keys, bridges, springs, regulators etc), along with the camshaft controlling these valves (SOHC) - or camshafts in case two of them are involved (DOHC) - are completely abolished. For simplification reasons a single cylinder engine operation is described in the lines to follow, but the same operational principles are applied in case of a multi-cylinder engine regardless its cylinder arrangement (in series, V, W etc). Furthermore, transmission of crankshaft’s rotation to the special designed driven cylinder head described below involve gears, idle gears and a shaft, but the same principle may equally well be realized by chain, shaft, belt as seen in Drawing 19 etc.

The invention is described below with reference to the accompanying drawings, in which: Drawing 1 displays an overview of the engine which includes the crankshaft (29), the connecting rod (28), the liner (27), the cylinder head (7) the rotating driven gear (1), the transmission (30) as well the fuel inlet (24) and exhaust pipe (25).

Drawing 2 displays the cylinder head as a whole (7) with its inlet (8) and outlet (9) ports across each other. These ports are located facing each other in different height each other in the circumference of the cylinder head (7) and at the same height with their respective fuel inlet pipe (24) and exhaust pipe (25). A groove (10) running around the head is also manufactured in which a thrush bearing (16) is seated. The thrush bearing (16) is mounted to the body of the cylinder head with bolts which are fitted in the relevant holes (15) deployed all around the cylinder head (7). A cover (20) is placed on the top of the cylinder head, secured by bolts in the holes (11 ) located on its upper surface.

Drawing 3 displays the same cylinder head (7) with its inlet (8) and outlet (9) ports as well the mounting holes (15) of the thrush bearing (16) from a different angle, wherefrom the holes (23) in which bolts secure the cylinder head (7) to the engine’s block can be seen.

Drawing 4 displays a cross section of the same cylinder head (7), where its inlet (8) and outlet (9) ports, the thrush bearing groove (10) where the thrush bearing (16) is mounted in the relevant holes (15) of the cylinder head (7) and the sealing groove (14) where a sealing ring is installed for combustion gases sealing can all be seen. Moreover, in drawing (4) it can also be seen the cooling (with coolant) chambers (13) of the cylinder head - in case the engine operates as air-cooled those chambers are not necessary - as well. A slot (12) for the installation of a spark plug (26) at the top of the cylinder head (7) is provided whereas in case of a self-ignited engine (i.e., when fueled with diesel) there is no need for spark plug installation and this slot (12) is blind. Finally, point (11) shows the holes in which the cover (20) is fastened with bolts, and holds the rotating driven gear (1), described below, in place.

Drawing 5 displays the thrush bearing (16) which is mounted at the thrush bearing groove (10) of the cylinder head (7) and fastened with bolts, deployed all around it, in its holes (19). Thrush bearing (16) is equipped with small bearings deployed all around it in its bottom surface. During operation these bearings are in direct contact with the rotating driven gear (1) enabling frictionless rotation.

Drawing 6 displays the thrush bearing (16) in cross section where the "male” channel (17) - which fits into the "female” groove (10) of the cylinder head (7) - as well the holes (19) in which bolts fasten it as they end in the holes (15) located at the body of the cylinder head (7) can be seen.

Drawing 7 displays the cylinder head (7) with the thrush bearing (16) mounted in it.

Drawing 8 displays the rotating driven gear (1 ) which, although in one piece, consists out of the following parts:

• the upper "toothed” part (2), and

• the lower cylindrical part (3).

The upper part (2) ensures the rotation of the whole arrangement as it is driven by the transmission arrangement (30) which, in turn, driven by the crankshaft (29). The lower cylindrical part (3) of the rotating driven gear (1) is equipped with ports, inlet (5) and outlet ones (4) in different height, which are rotate with the same angular speed with the upper "toothed” part, since the whole gear (1) is and operates actually as one piece. As the rotating driven gear (1 ) rotates around the cylinder head (7), these ports either connect or isolate combustion chamber with the fuel inlet pipe (24) and the exhaust pipe (25) accordingly. The exact dimensions of these ports (4) and (5), as well as their shape, are determined by the desirable amount of intake mixture as well as by the engine’s combustion volume. The combustion chamber is sealed by means of sealing rings (6) installed in the cylindrical lower part (3) of the rotating driven gear (1 ) as well as by means of sealing rings (14) installed at the inlet (8) and outlet (9) ports of the cylinder head (7). In the body of the lower cylindrical part (3) of the rotating gear, at the contact surface with the cylinder head (7), grooves (6) are manufactured for the installation of the above sealing rings. Grooves (14) are also manufactured in the body of the cylinder head (7) around its inlet (8) and outlet (9) ports, in which sealing rings are installed as well. With the installation of sealing rings in the grooves (6) and (14), complete isolation of the combustion chamber from the fuel inlet (24) and exhaust pipe (25) is ensured, depending on the timing of the thermodynamic cycle. At the same time, the sealing rings (6) and (14) maintain the compression pressure steady. The rotating driven gear (1) is mounted into the body of the cylinder head (7) in such a way that:

• the inlet ports (5) of its lower cylindrical part (3) are at the same height with the inlet port (8) of the cylinder head (7), and

• the outlet ports (4) of the cylindrical part (3) are at the same height with the outlet port (9) of the cylinder head (7). Drawing 9 displays the rotating gear (1) with its upper "toothed” part (2) and its cylindrical lower part (3) from a different angle, whereas the inlet (5) and outlet (4) ports can also be seen.

Drawing 10 displays in cross section the rotating driven gear (1 ) with its upper "toothed” part (2) and its cylindrical lower part (3) from a different angle, whereas the inlet (5) and outlet (4) ports can also be seen.

Drawing 11 displays the cover (20) which is mounted on the top of the cylinder head

(7).

Drawing 12 displays the cover (20), which is mounted on the top of the cylinder head (7) from a different angle. Mounting is realized with bolts, which are fastened in the holes (22) located in the upper part of the cover (20) and secured in the corresponding holes (11) in the body of the cylinder head (7). The cover (20) has also a hole in the center so that, if we a spark-plug ignite engine is employed, the spark plug (26) can be mounted in the relevant socket (12) of the cylinder head (7), otherwise, in case of a self-ignite engine, the cover (20) is blind. The installation of the cover (20) allows for the rotating driven gear (1 ) to turn around and within the cylinder head (7), thus preventing its axial movement. Finally, the cover (20) in its lower part is equipped with bearings (21 ), which are in contact with the upper surface of the "toothed part” (2) of the rotating gear (1) providing for as frictionless contact as possible during operation.

Drawing 13 displays in cross section the cover (20), mounted on the top of the cylinder head (7), wherefrom the mounting holes (22) can be seen as long with the bearings (21 ) which, during operation, are in contact with the "toothed part” (2) of the rotating gear (1), thus facilitating its rotation.

Drawing 14 exhibits a section of the cylinder head (7) particularly focusing on the inlet port (8), around which three grooves (14) are deployed as in the outlet port (9) but in different height. These grooves are appropriate for the installation of relevant sealing rings, placed to secure better sealing in high compression engines. More or less grooves can be considered depending on the desirable sealing efficiency.

Drawing 15 shows the cylinder head (7), in which the rotating driven gear (1) and the cover (20) are interlocked forming an overall cylinder unit.

Drawing 16 shows the same arrangement as drawing 15 from a different angle, where the thrush bearing (16) installed in the groove (10) of the cylinder head (7) can also be seen, besides the rotating driven gear (1) and the cylinder head (7).

Drawing 17 displays a cross-sectional arrangement, in which all of the above- described parts appears to be interlocked as an overall cylinder unit. In this drawing, the cylinder head (7), the rotating gear (1 ), the cover (20) as well as the thrush bearing (16) can be seen.

Drawing 18 displays the overall cylinder unit in cross section, namely, the cylinder head (7), the rotating gear (1), the cover (20), the thrush bearing (16) as well as the mounting holes (23) of the cylinder head (7) to the engine’s block, attached to the engine’s liner (7), where the piston (31) operates. The fuel inlet pipe (24), the exhaust pipe (25) and the connecting rod (28) can also be seen.

Drawing 19 displays the engine using a belt (32) for transmission purposes.

Drawing 20 displays a multi-cylinder engine where, starting form rotating driven gear connected with the transmission arrangement (30), each cylinder drives the following one by the engagement of their respective rotating gears.

As shown in Drawing 1 , the transmission of crankshaft’s rotation to the rotating gear is achieved via an arrangement, which involves a shaft, idle and bevel (conical) gears (30). Bevel gears convert the vertical rotational motion of the crankshaft and the planetary (idle) gears to horizontal motion, suitable for rotating the horizontally mounted rotating driven gear (1) on the cylinder head (7) crown. This arrangement eliminates the need to use a camshaft. It is stressed out that the planetary and bevel gears with the shaft shown in Drawing 1 are indicative. The calculation of coupling ratio of these gears is out of the scope of this document. It is also pointed out that the transmission of crankshaft’s rotation to the rotating driven gear (1 ) can be also realized by different arrangements, i.e. with belt (32) as shown in Drawing 19 or with gears alone (without a shaft), etc.

Now, regarding this one-cylinder engine, at the top of the cylinder a cooled cylinder head (7) is mounted, which connects the combustion chamber with the fuel inlet (24) and exhaust pipe (25). In drawings 2 and 3 this cooled cylinder head (7) can be seen in different angles, while in drawing 4 it can be seen in cross section. It has fixed openings, permanent inlet (8) and outlet (9) ports, which are across and at the same heigh level with their respective fuel inlet (24) and exhaust (25) pipes of the engine. At the periphery of the cylinder head (7), a groove (10) is manufactured in which the thrush bearing (16) - described in drawings 5 and 6 - is seated and secured by bolts, ensuring frictionless rotation of the rotating driven gear (1), as shown in Drawings 8, 9 and 10, around and inside the cylinder head (7).

Drawing 5 displays the thrush bearing (16) mounted in the cylinder head (7), while Drawing 6 displays a cross section of it. In Drawing 6, the "male” groove (17) is mounted into the "female” groove (10) of the cylinder head (7) and fastened to its body with bolts, which are placed in the holes (19) and terminated in the corresponding ones (15) located in the cylinder head (7). In a conventional engine following the Otto cycle (or Atkinson - the engine can be operated in other thermodynamic cycles mode as well), each complete thermodynamic cycle (suction, compression, expansion and exhaust) includes two complete turns of the crankshaft for one complete turn of the camshaft with all relevant rotations / movements and stress of the rest mechanical parts controlling the combustion (valves, keys, springs etc). That is, for every two complete turns of the crankshaft, or every 720°, camshaft is turned correspondingly once, or 360°. By the present invention, the angular speed of the rotating driven gear (1) can be substantially reduced as follows: each conventional camshaft has one [1] cam, controlling the inlet valve of a conventional cylinder head and one [1] cam controlling the outlet valve. Since inlet and outlet valves are opening just once per thermodynamic cycle, the camshaft is turns by half the speed of the crankshaft. In the context of the current innovation, this corresponds to one [1] inlet port (5) and one [1] outlet port (4) in the rotating driven gear (1 ). However, given the much bigger diameter and circumference of the cylindrical part (3) of the rotating driven gear to that of a conventional camshaft, instead of one [1] inlet port (5) and one [1] outlet port (4), more can be manufactured in the cylindrical part (3) of the rotating driven gear (1) reducing its angular speed depending on their number. More specifically, one [1] inlet (5) and one [1] outlet (4) port will correspond to half the angular speed of the rotating driven gear (1) in comparison to the angular speed of the crankshaft as would be the case with a conventional engine. However, two [2] inlet ports (5) arranged across each other in the cylindrical part (3) of the rotating driven gear (1) and two [2] outlet ports

(4) in the same arrangement, will cause the rotating driven gear (1) to be turned at quarter the angular speed in comparison to that of the crankshaft so as to realize the four-stroke operation. In such a way, every thermodynamic cycle, during which inlet

(5) and outlet ports (4) need to be opened just once, can be realized with just half the turn of the rotating driven gear (1). Respectively, if three [3] inlet ports (5) placed in an 120° arc in the cylindrical part (3) of the rotating driven gear (1) and three [3] outlet ports (4) in the same arrangement are installed, this will cause the rotating driven gear (1 ) to be turned at an angular speed six times less in comparison to that of the crankshaft. Likewise, if four [4] inlets ports (5) placed in a 90° arc and four [4] outlet

(4) in the same arrangement are installed, this will cause the rotating driven gear (1) to be turned at an angular speed eight times less in comparison to that of the crankshaft, and so on. In big engines with larger liner circumference, even more inlet

(5) / outlet (4) ports could be respectively installed.

Summing up, the relation between the rotating driven gear (1) angular speed and the crankshaft (29) angular speed as a function of the number of inlet (5) and outlet (4) ports manufactured in the circumference of the cylindrical part (3) of the gear (1) is expressed by the following equation: Vc

Vg = (a)

2 * Np where:

• V _g : Rotating Driven Gear (1) Angular Speed (Velocity gear)

• V _c : Crankshaft Angular Speed (29) (Velocity crankshaft) · N _P : Number of Inlet (5) or Outlet (4) ports (Number of ports)

Depending on the number of ports in the cylindrical part (3), adjust the speed of the rotating driven gear (1), or the rotating driven gears in case of a multi-cylinder engine, can be easily adjusted by adjusting respectively the ratio of the idle gears of the transmission arrangement (30). The same result can be obtained in the case of a belt, as shown in Drawing 19, chain, shaft etc.

A great advantage of the above-described arrangement is that by reducing the angular speed of the rotating gear (1), the associated friction, damages, O&M cost, noise during operation etc, are reduced respectively, while at the same time ICE’s efficiency and reliability/longevity are substantially increased. In fact, the more the ports manufactured in the cylindrical part (3) of the rotating drive gear (1 ), or the higher the Np in equation (a), the better the results. In addition, the use of a rotating driven gear (1) bearing ports, eliminate the need for camshafts and all related valve train control equipment and control keys, which significantly increases complexity, results in lower reliability and increases operation cost of an ICEs.

The operation of the application is described below for the well-known Otto cycle (or Atkinson - the device can be used in other cycles as well), and based on a single- cylinder ICE, (the operational principles being exactly the same regardless of the number of cylinders, two-cylinder, four-cylinder etc., and their arrangement, i.e., in series, in V, in W etc.). Transmission from the crankshaft (29) described below involves gear and shaft (30) but exactly the same results if a belt (32) as shown in Drawing 19, chain, planetary gears or any combination of these is considered. In addition, below is described a rotating driven gear (1) with four [4] inlet ports (5) and four [4] outlet ports (4) which, as duly mentioned above, will allow the gear to be turned eight times less the angular speed of the crankshaft (29) for each full thermodynamic cycle (suction, compression, expansion and exhaust). In other words, for every full turn of this - four [4] inlet/outlet ports equipped - rotating driven gear (1), crankshaft (29) will rotate eight times realizing the four 4-stroke thermodynamic cycles (like the

Otto-cycles considered).

It is pointed out that engine’s fuel inlet pipe (24), cylinder head’s (7) inlet port (8) and inlet ports (5) located in the cylindrical part (3) of the rotating driven gear (1 ) are at the same height fully aligned between them (in height) as the rotating driven gear (1) rotates. Respectively, the engine’s exhaust pipe (25), cylinder head’s (7) outlet port (9)) and outlet ports (4) located in the cylindrical part (3) of the rotating driven gear (1 ) are at the same height with one another, which is slightly different from that of the intake system, fully aligned (in height) as the rotating driven gear (1) rotates. The thermodynamic cycle now is as follows: in a given moment the inlet (8) and the outlet port (9) of the cylinder head (7) are in "blind” position in relation to their respective fuel inlet (24) and exhaust (25) pipes of the engine as between them stands the wall of the cylindrical part (3) of the rotating driven gear (1), thus isolating the combustion chamber from the fuel inlet (24) and exhaust (25) pipes. As the rotating driven gear (1 ) turns, driven by the crankshaft (29) through transmission system (30), the first of its four [4] inlet ports (5) located in the cylindrical part (3) starts to be aligned with the inlet port (8) of the cylinder head (7), which is located across and is fully aligned with the fuel inlet pipe (24) of the engine, so that fuel starts to fill the combustion chamber at the moment while the piston (31 ) is heading to top dead center (TDC). At the same time, the outlet port (9), which in the cylinder head (7) is located across inlet port (8) but in different height, starts to close, while the piston (31 ) is rising to allow the chamber to purge the combustion products of the previous cycle through the outlet port (9) and the exhaust pipe (25). Fresh fuel inserted by the just-opened inlet port (5) helping to scavenging, piston reaches TDC and, as the rotating driven gear (1 ) turns, the outlet port (4) completely closes, and the inlet port (5) continues to open filling the cylinder with fuel, while the piston (31) is now heading to the bottom dead center (BDC). At BDC, the combustion chamber is now full of fuel and the inlet port (5) closes as the rotating driven gear (1) turns and the inlet port (5) gradually loses its alignment to the fuel inlet pipe (24). The cylindrical part (3) rotates gradually to isolate the inlet port (5) and the fuel inlet pipe (24). At this point, the first stroke of the cycle, that is "intake”, has been completed.

Then, once the inlet port (5) is closed, the fuel is compressed and ignited at the proper timing by means of a spark plug (26) mounted at the socket (12) at the top of the cylinder head (7), or auto-ignited if fuel allows self-ignition operation, just before the TDC - at the appropriate ignition angle. At compression stroke the inlet (8) and outlet (9) ports of the cylinder head (7) are in "blind” position in relation to their respective fuel inlet (24) and exhaust (25) pipes as between them stands the wall of the cylindrical part (3) of the gear (1) therefore completely isolating combustion chamber and allowing the fuel mixture to be compressed. At the same time, sealing rings (6) deployed between inlet level ports (5) and outlet level ports (4) of the cylindrical part (3), and sealing rings (14) deployed around inlet (8) and outlet (9) ports of the cylinder head (7), prevent combustion gaseous products leakage maintaining compression steady. At this point, the second stroke of the cycle, that is the "compression”, has been completed. At combustion stroke, while piston (31) is at the TDC, fuel ignition causes the piston (31) to produce mechanical work by the engine, which is subsequently delivered to the crankshaft (29) via the connecting rod (28) causing its rotation. At this point, the third stroke of the cycle, that is the "combustion”, has been completed. As the piston (31 ) now starts to return from the BDC to the TDC, rotating driven gear (1) turns causing the outlet port (4) to be gradually aligned to the cylinder head’s (7) outlet port (9), clearing in this way the combustion chamber from the combustion products (exhaust gases) which are removed / evacuated through the exhaust gas pipe (25). Just before the piston (31) reaches the TDC and before the outlet port (4) closes, actually loses its alignment with the outlet port (9) of the cylinder head (7), the inlet port (5) starts to open, be aligned to the inlet port (8) of the cylinder head (7), allowing fuel to start filling the combustion chamber clearing it from the combustion products - exhaust gases - (scavenging) up to the point whre the piston touches the TDC and the outlet port (4) completely closes. At this point, the fourth stroke of the cycle, that is the "exhaust” has been completed, and a new cycle is able starts to be initiated.

As, in the context of the above description, the rotating driven gear (1) is equipped with four [4] inlet / outlet ports, for the entire thermodynamic cycle to be realized, the turn of the rotating driven gear (1) required will be only 90°, while the crankshaft performs two full revolutions, or 720°.

It is pointed out that the rotating driven gear (1 ) and the cylinder head (7) as shown in Drawing 15 are separate and detachable from the engine’s liner (27). This detachable head involves its fixed (7, 16, 20) and its moving (rotating) (1 ) part as described above, while the rest parts such as the liner (27), the piston (31), the connecting rod (28) are fitted to the engine’s block as shown in Drawing 18. The casting of both parts at their joining surface is done in such a way that are completely fit each other (male / female grooves) so as to create a single operational liner. This arrangement allows for easy dismantling of the parts from each other, in case either for maintenance or for repair.

For simplicity reasons, the operation of a single-cylinder ICE was described above, but the principals of operation are exactly the same for a multi-cylinder engine as shown in Drawing 20, by simply engagement of their respective rotating driven gears (1). Drawing 20 shows four-cylinder in series ICE, but more or less cylinders can be engaged either in series, V, W or in any other arrangement.

Another simplification was that in the description above fuel inlet (24) and exhaust (25) pipes where placed across each other in an 180° degree arrangement, but they can be placed in smaller angles to be selected if this facilitates engine’s construction.

Advantages: The engine described above has several advantages over a current conventional internal combustion engine (ICE), the main of which are the following:

Conventional cylinder head is completely removed. The cylinder head (7) used here is much simpler as it does not include valve train, i.e., control keys, bridges, springs, regulators, etc., and is, therefore, more reliable, less prone to damage, less expensive to build, smaller in size, more compact and quieter during operation.

The need for camshaft(s) as well as for push rods, tappets etc. is completely eliminated. Therefore, there are fewer mechanical parts resulting in less power loss and consequently higher engine efficiency with lower fuel consumption.

There is much better cooling of the combustion chamber due to the absence of a classic cylinder head and the installation of the water cooler cylinder head (7) in its place, with the cooling chambers (13) as shown in Drawing 4, to results to cooling down the combustion chamber exactly to the point where it gets the maximum thermal stress - that is, at the piston crown. More efficient cooling results to less thermal stress and therefore prolongs service intervals and the expected operational life of the mechanical parts. More efficient cooling also causes less and smaller uncontrolled self-ignitions (knocking), which are frequently created as a result of the insufficient fuel cooling.

Due to the absence of a conventional cylinder head with its control keys, service intervals will be much longer since there is no need for valve adjustment or camshaft and its auxiliary equipment (push rods, tappets etc.) maintenance requirements.

The absence of a conventional cylinder head eliminates the irregularities and the discontinuities on the surface on the ceiling of the combustion chamber where deposits are formed which, in turn, often leading to uncontrolled ignitions (knocking) reducing in this way engine’s efficiency or, even worse, causing undesirable catastrophic failures.

At the top dead center (TDC), the piston gets very close to the - now completely flat ceiling due to the absence of valves - ceiling of the combustion chamber, and the resultant squish turbulence results to improve fuel / air mixing, meaning more efficient combustion. Additionally, the shape of the combustion chamber (no valves at its ceiling) allows for even higher compression ratio and substantially higher engine performance.

A major advantage in comparison to a conventional ICE engine where one turn of the camshaft(s) requires two turns of the crankshaft for a complete thermodynamic cycle to be realized, here, for every complete turn of the rotational driven gear (1), two, three, four or even more thermodynamic cycles can be resized depending on the number of ports this rotating driven gear is equipped with according to equation (a). This enables rotating driven gear (1) to be turned significantly slower, two, four, six, eight or even more times according to equation (a), in comparison to the crankshaft, allowing of a wider range of rpm to be reached, resulting to a much higher reliability with less friction, lower thermal stress, lower efficiency losses, fuel saving etc. Finally, the height, and effectively the dimensions of the inlet ports (5) of the cylindrical part (3) of the rotating gear (1) can be so adjusted as to allow for more mixture to fill into the combustion chamber during the intake stroke. This can result to an engine of smaller dimensions for the same performance and / or smaller turbo charger as well to much higher efficiency of the engine.