GB2374386A - I.c. engine cylinder block with increased oil capacity - Google Patents

Abstract

A tray-like apron 1 is sealably mounted eg to each side wall 6,7 of the cylinder block to provide further lubricating oil reservoirs 11 in addition to the usual sump 10. Oil return apertures 45 provide communication between the reservoirs 11 and the crankcase housing 19 and holes 67 may be provided in the cylinder block base 5 to allow oil to drain from the reservoirs 11 into the sump 10. The apron 1 may be formed from steel or aluminium sheet and may be attached by adhesive and mechanical fasteners. The bottom of each apron 1 may comprise a box beam 32 for stiffness. The apron 1 may have separate or integral heat exchangers 55a, 55b to improve oil cooling. The apron 1 may provide for mounting engine accessories or to carry identification or instructions.

Description

1 CYLINDER BLOCK ASSEMBLY WITH LUBRICATING FLUID

2 RESERVOIR

4 Technical Field

6 This invention relates to a cylinder block having an 7 increased engine oil capacity and to an internal 8 combustion engine including the cylinder block. The 9 invention also relates to a method for lubricating an 10 engine.

12 Background

13. 14 During operation of an engine, a lubricant such as 15 engine oil is pumped from a sump into the working 16 portions of an engine in order to lubricate, clean 17 and cool the engine's moving parts. Excess oil 18 supplied to the moving parts is drained back to the 19 sump along various paths defined in the engine 20 cylinder block and cylinder head.

1 A large volume of lubricating oil is desirable in an 2 engine. For example, where the volume of engine oil 3 is increased, degradation of the oil volume will be 4 slower, therefore service intervals can be increased 5 to minimize maintenance costs. The acceptable level 6 of degradation is governed largely by the level of 7 carbon contamination and it has been found desirable 8 to limit this contamination to a maximum of 21.

10 However, the volume of oil which can be employed in 11 an engine is limited by engine size as, in general, 12 it is desirable to maintain the engine envelope size 13 at a minimum whereas large volumes of oil require 14 large storage reservoirs in an engine. It may be 15 particularly desirable to minimize any sideways or 16 downward extension of the engine sump since the sump 17 is frequently close to fouling engagement with 18 vehicle cross-members, steering linkages, etc. 20 UK Patent Specification No 1499588 describes an

21 internal combustion engine having a lateral oil 22 reservoir fitted alongside the crankcase which 23 replaces the conventional oil sump. During 24 operation, oil is pumped from the reservoir to a 25 lubricating system and from a base of the crankcase 26 back to the reservoir. While the absence of a 27 conventional oil sump underneath the crankcase 28 provides good ground clearance, the position of the 29 reservoir necessitates the use of an additional pump 30 to return oil from the crankcase to the reservoir.

31 Further, the narrow and elongated shape of the

1 reservoir, added to the velocity of the oil through 2 the reservoir, tend to inhibit or slow passage of 3 gases from the oil to an engine breather system.

5 The present invention is directed to solving one or 6 more of the problems set forth above.

8 Summary of the invention

10 According to the invention there is provided a 11 cylinder block assembly comprising a cylinder block, 12 a lubricating fluid sump, a crankcase housing in the 13 cylinder block, an aperture in the crankcase housing, 14 an apron sealably mountable on the cylinder block, 15 and a fluid reservoir defined between the apron and 16 the crankcase housing and adapted to receive 17 lubricating fluid, the fluid reservoir being 18 communicable with the crankcase housing through the 19 aperture.

21 The invention also extends to an engine comprising a 22 cylinder block, a lubricating fluid sump, a crankcase 23 housing in the cylinder block, an apron sealably 24 mounted on the cylinder block, a fluid reservoir 25 defined between the apron and the crankcase housing, 26 and a fluid passage extending between the reservoir 27 and the crankcase housing, wherein the fluid 28 reservoir contains lubricating fluid.

30 The invention also extends to a method for 31 lubricating an engine of the type comprising:

1 a cylinder block; 2 a lubricating fluid sump; 3 an apron sealably mounted on the cylinder block; and 4 a lubricating fluid reservoir defined between the 5 cylinder block and the apron, 6 the method including the step of supplementing a 7 level of lubricating fluid in the sump with 8 lubricating fluid from the reservoir.

10 Brief Description of the Drawings

12 Various embodiments of the invention will now be 13 described, by way of example only, having regard to 14 the accompanying diagrammatic drawings in which: 16 Figure 1 is an isometric view of an engine 17 including a cylinder block assembly in accordance 18 with the invention made up of an apron mounted on a 19 cylinder block with a portion of the apron cut-away 20 to reveal the cylinder block side wall; 22 Figure 2 is an isometric view of the engine of 23 Figure 1 with the apron removed; and 25 Figure 3 is a schematic cross-sectional end view 26 of the engine of Figures 1 and 2 relating to further 27 embodiments of the invention to include heat exchange 28 elements located on an external face of the apron and 29 alternative attachment means for attaching the apron 30 to a cylinder head and a sump.

1 Detailed Description

3 As shown in the drawings, a cylinder block apron in 4 accordance with the invention is a generally tray 5 like apron 1 sealably mountable on and co-operable 6 with a cylinder block 2 which is adapted to receive 7 the apron 1 in a fluid tight relationship. The apron 8 1 sealably encloses engine oil and crankcase gases to 9 provide a fluid reservoir 11 between the apron 1 and 10 the cylinder block 2 thereby acting as an engine oil 11 capacitor.

13 The cylinder block 2 shown in the Figures is a cast 14 cylinder block having a flanged cylinder block base 15 5. The cylinder block 2 includes a cylinder block 16 first side wall 6, a cylinder block second side wall 17 7 substantially parallel with the cylinder block 18 first side wall 6, a cylinder block front end wall 8 19 and a cylinder block rear end wall 9 all upstanding 20 from the cylinder block base 5. In the present 21 example, the first side wall 6 is substantially non 22 machined, so that it is substantially free of tapped 23 bosses, machined faces, extended structures and other 24 features normally required to secure ancillary engine 25 components to the cylinder block 2.

27 The cylinder block 2 is provided with a cylinder head 28 20 fitted with a cylinder head cover 21. The 29 cylinder head 20 is provided with an integral air 30 inlet manifold 22.

1 The side walls 6, 7 are shaped to define a crankcase 2 housing 19 adjacent the cylinder block base 5 for 3 housing a crankcase 44. The side wall 6 is provided 4 with passages in the form of cylinder block draining 5 holes 17 to facilitate oil drainage from cylinder 6 head drainage holes 18 in the cylinder head 20. A 7 sump 10 abuts the cylinder block base 5.

9 The cylinder block rear end wall 9 is provided with a 10 rear bearing plate 12 which projects laterally 11 outwards from the first side wall 6. The bearing 12 plate 12 has an inner face 16 disposed towards the 13 cylinder block first side wall 6. The rear bearing 14 plate 12 is provided with a bore to receive engine 15 ancillary components. Similarly, the front end wall 16 8 is provided with a front bearing plate 14 which 17 projects laterally outwards from the first side wall 18 6. The bearing plate 14 is provided with a mounting 19 bore 54. The front end wall 8 projects laterally 20 outwardly from the second side wall 7.

22 The cylinder block 2 and the cylinder head 20 are 23 provided with attachment points for facilitating 24 attachment of the structural apron 1. More 25 particularly, the cylinder block 2 is provided with 26 adhesive sealant attachment points 24 and mechanical 27 attachment points 25 as will be described later, 28 while the cylinder head 20 is provided only with 29 mechanical attachment points 25 in order to 30 facilitate any required subsequent removal of the 31 cylinder head 20 from the cylinder block 2 and apron

1 1. Although the Figures show the attachment of the 2 apron 1 to the side walls, 6, 7, it is to be 3 understood that the apron may be attached to any 4 suitable surface or combination of surfaces of the 5 cylinder block 2.

7 The adhesive sealant attachment points 24 are made up 8 of a sealant receiving border 15 defined on the 9 periphery of the first side wall 6. The sealant 10 receiving border 15 is substantially quadrilateral in 11 shape and extends around a perimeter defined by a top 12 outer edge 38 on the side wall 6 adjacent the 13 cylinder head 20, a bottom outer edge 40 of the side 14 wall 6 adjacent the cylinder block base 5, an outside 15 edge 41 of the front bearing plate 14 and an end edge 16 42 adjacent the rear bearing plate 12. The sealant 17 receiving border 15 forms a mating surface and is 18 adapted to receive an adhesive sealant 43 between the 19 cylinder block 2 and the apron 1 to define the fluid 20 reservoir 11. The apron 1 has a mating surface which 21 corresponds to the mating surface of the receiving 22 border 15. The sealant 43 is applied between the 23 mating surfaces and serves to ensure that the fluid 24 reservoir 11 is fluid tight and is able to hold 25 lubricating fluid such as oil.

27 The adhesive sealant attachment points 24 are also 28 made up of adhesive sealant receiving ribs 26 formed 29 on the side wall 6 of the cylinder block 2 for 30 receiving adhesive sealant to adhesively secure the 31 apron 1 to the side wall 6. The ribs 26 extend

1 vertically upwards from the crankcase housing 19 to 2 the top outer edge 38 of the side wall 6.

4 Preferably, the cylinder head 20 has threaded holes 5 27 surrounding the inlet manifold 22. The threaded 6 holes 27 are adapted to receive fasteners to 7 mechanically secure the apron 1 to the cylinder head 8 20. 10 As indicated above, the apron 1 is substantially 11 tray-like in shape. The apron 1 is formed from a 12 sheet metal material or other suitable material 13 shaped or configured so that the apron 1 is adapted 14 to sealably attach to the side wall 6 of cylinder 15 block 2 to define the fluid reservoir 11 16 therebetween. Each side wall 6, 7 can be provided 17 with an apron 1 if desired.

19 The apron 1 is dimensioned according to the 20 dimensions of the cylinder block 2. For example, the 21 apron 1 is dimensioned to fit between the rear 22 bearing plate 12 and the front bearing plate 14 and 23 between the cylinder block base 5 and cylinder head 24 20 on the side wall 6.

26 The apron 1 is made up of a bottom portion 29, a 27 central cylinder block portion 30 and a top cylinder 28 head portion 31.

30 The bottom portion 29 of the apron 1 is folded to 31 define an elongate beam 32 having a box-like cross

1 section. The box-like elongate beam 32 is therefore 2 made up of a beam bottom wall 33 having elongate 3 first and second beam side walls 34, 35 respectively 4 upstanding therefrom. The box-like beam 32 is 5 further provided with a beam top wall 36 extending 6 between the first and second beam side walls 34, 35 7 respectively.

9 The beam bottom wall 33 is provided with a series of 10 spaced apart beam attachment holes 37 to facilitate 11 attachment of the apron 1 to the sump 10.

12 The elongate beam 32 provides additional and 13 efficient stiffness to an assembled engine structure 14 while the box-like construction serves as a chassis 15 rail and provides stiffened engine mounting 16 locations.

18 The central cylinder block portion 30 is contiguous 19 with the apron bottom portion 29 and is shaped and 20 folded to abut the side wall 6 at the adhesive 21 sealant receiving border 15 and to define the 22 reservoir 11 between the apron 1 and the cylinder 23 block 2.

25 The central cylinder block portion 30 of the apron 1 26 is made up of an upstanding panel 39 which is adapted 27 to abut the ribs 2 6 on the cylinder block 2 to 28 sealably secure the apron 1 to the ribs 26.

30 The top cylinder head portion 31 is made up of an 31 upright cylinder head panel 46 contiguous with the

1 upstanding panel 39. The cylinder head panel 46, 2 like the upstanding panel 39, is disposed in a 3 substantially upright disposition and is shaped at 4 its free end to define an elongate top rail 47. The 5 top rail 47 projects outwardly away from the cylinder 6 head 20.

8 The top rail 47 provides additional stiffness to an 9 assembled engine structure while in an alternative 10 embodiment also serving to attach the apron 1 to the 11 cylinder head 20. In a still further embodiment, 12 with particular reference to Figure 3, the top rail 13 47 can also be adapted to be fastened to the cylinder 14 head cover 21 if required.

16 The cylinder head panel 46 has a top series of spaced 17 apart mounting holes 48 located adjacent the top rail 18 47 and a bottom series of spaced apart mounting holes 19 49. The top series of mounting holes 48 and the 20 bottom series of mounting holes 49 are adapted to 21 receive fasteners for securing the cylinder head 22 panel 46 to the cylinder head 20.

24 The cylinder head panel 46 has an aperture 50 to 25 facilitate communication between an elbow connector 26 51 engageable with the aperture 50 and the air inlet 27 manifold 22 within the cylinder head 20.

29 As shown in Figure 1, the apron 1 is mounted on the 30 cylinder block first side wall 6. However, it will 31 be appreciated that a suitably shaped apron 1 can

1 alternatively or additionally be mounted on the 2 second side wall 7.

4 The apron 1 is fastened to the side wall 6 by 5 fasteners 56 inserted through holes 57 in a flange 58 6 of the sump 10, through corresponding holes 59 in a 7 flange 60 of the cylinder block 2 and hence into 8 threaded holes 61 in the beam bottom wall 33. The 9 fasteners 56 also thus secure the sump 10 to the 10 apron 1 and hold the sump 10 tightly against the 11 cylinder block base 5.

13 The fasteners 56 also facilitate the attachment of an 14 optional sump guard to the apron 1 if required.

16 The apron 1 is fastened to the cylinder head 20 by 17 fasteners 53 inserted through the mounting holes 48, 18 49 of the cylinder head panel 46 into the 19 corresponding threaded holes 27 in the cylinder head 20 20.

22 In a further embodiment, with particular reference to 23 Figure 3, the apron 1 may be fastened to the cylinder 24 head 20 by fasteners 63 inserted through a series of 25 spaced apart mounting holes 64 in a flange 65 of 26 cylinder head 20 and into corresponding threaded 27 holes 66 formed in the top rail 47. The fasteners 63 28 may optionally also secure cylinder head cover 21 as 29 shown in the figure.

1 The fasteners 53, 56, 63 can be any suitable 2 fasteners such as threaded screws or studs and nuts.

3 Threaded holes 61, 66 can be formed by any 4 conventional means such as weld nuts, rivet nuts, 5 edge clips and the like. Alternatively, threaded 6 holes 61, 66 can be formed by the "Flowform" (Trade 7 Mark) process in which a hole is pierced in apron l 8 and thread-rolled. Alternatively further, fasteners 9 56, 63 may be weld studs, self-tapping screws, rivets 10 or the like, in which case the holes 61, 66 will not 11 need to be pre-threaded.

13 As previously described, attachment of the apron 1 to 14 the cylinder block 2 is via the adhesive sealant 15 receiving border 15 and the adhesive sealant 16 receiving ribs 26. Suitably, a sealing adhesive 17 could be applied by a robot applicator or screen 18 printing of the adhesive on to the apron 1.

20 Fluid is received into the reservoir 11 through the 21 draining holes 17 in the side wall 6 which facilitate 22 fluid communication between the reservoir 11 and the 23 cylinder head 20. Fluid from the reservoir 11 is 24 returnable to the crankcase 44 through return 25 apertures 45 in the crankcase housing 19 which 26 facilitate communication between the reservoir 11 and 27 the crankcase housing 19.

29 Accordingly, the reservoir 11 serves as an oil 30 capacitor to supplement the oil sump 10. The 31 reservoir 11 fills from the draining holes until the

1 oil level is level with the return apertures 45 2 whereupon the overflow oil is returned via the 3 apertures 45 in the crankcase 44 to the sump 10.

4 Holes 67 in the cylinder block base 5 facilitate a 5 controlled flow of oil from the reservoir 11 to the 6 sump 10, thus ensuring, firstly, movement of the 7 whole volume of oil through the engine filtration and 8 lubrication system and, secondly, providing a 9 reservoir oil drain means during engine servicing.

11 Figure 3 further shows an alternative embodiment of 12 an apron 1 of the invention mounted on a cylinder 13 block 2. The apron 1 is broadly similar to the apron 14 1 previously described, accordingly like numerals 15 indicate like parts. The apron 1 is mounted on the 16 side wall 6 of the cylinder block 2. However, in the 17 present embodiment, the apron 1 is provided on its 18 outer surface with one or more cooling elements in 19 the form of heat exchanging baffles 55a, 55b 20 extending laterally outwards from the apron 1 at the 21 central cylinder block portion 30 to facilitate 22 cooling of engine oil contained within the reservoir 23 11 between the apron 1 and the cylinder block 2. The 24 baffles 55a, 55b therefore contribute to convective 25 cooling of oil within the reservoir 11.

27 The reservoir 11 also allows de-aeration of oil and 28 gases in an engine due to the increased capacity and 29 also promotes condensation of gases.

1 The cooling element may be attached to the apron 1 as 2 separate baffles 55a or integrally formed baffles 55b 3 which are part of the apron 1. Thus, the cooling 4 element may be fluidly isolated from the reservoir ll 5 or may be fluidly connected to the reservoir. Where 6 the cooling element is fluidly connected to the 7 reservoir 11 (see baffles 55b), improved oil cooling 8 efficiency and an increase in the oil capacity of the 9 reservoir may be expected. The triangular prismatic 10 outer shape of the baffles is helpful in avoiding the 11 retention of ambient foreign matter which would 12 reduce thermal transfer efficiency.

14 The apron 1 may include provision for mounting engine 15 ancillaries and accessories. Examples of such engine 16 accessories and auxiliary components include, but are 17 not limited to: engine electronic control units and 18 wiring harnesses, clips and ties; low pressure fuel 19 system components such as lift pumps, filters, pipes; 20 high pressure fuel systems including fuel injection 21 pump support brackets; lubrication system components 22 including remote filter mountings, electric oil 23 pumps, hose attachments and closed circuit breather 24 system components; cooling system components 25 including electrical cooling pumps, mechanical 26 cooling pumps, hose attachments, heat exchangers for 27 oil and EGR systems and fan mountings; ancillary 28 drives including brackets and attachments for 29 alternators, PAS pumps, vacuum pumps, compressors, 30 air conditioning pumps, idler pulleys, tensioners and 31 other driven accessories; air system components

1 including air ducts and bunking, inlet manifolds and 2 elbows, inlet air heat exchangers, exhaust mountings, 3 TO oil drain supports and the like; emissions system 4 components including mountings for closed coupled 5 after-treatment devices and EGR components; engine 6 mounting parts; transmission mounting parts.

8 In the given example, apron 1 is envisaged as having 9 a thickness of from about 2 to about 4 millimetres 10 but thickness selection will need to take into 11 account variables such as the required stiffness, 12 ease of forming and the duty to which the apron is to 13 be subjected to, as well as any accessories to be 14 mounted thereon and whether engine mountings and 15 transmission housings are to be attached thereto.

16 The apron 1 may be reinforced locally as required.

17 The apron can be flat folded and bent or pressed to 18 shape as required.

20 The apron 1 can be formed from high strength low 21 alloy (HSLA) steel but can also be formed from cold 22 rolled mild steel, aluminium sheet or any other 23 material having suitable characteristics. The apron 24 1 can be configured by, for example, laser machining 25 or the like or may be numerically controlled punch 26 profiled. The apron 1 may be folded by a brake press 27 and deep drawn for pressed features.

29 In an alternative embodiment of the invention, the 30 apron 1 can be provided with front and/or rear 31 flanges (not shown) to assist in fixing the apron 1

1 to the front wall 8 or rear end wall 9 of the 2 cylinder block 2. Where the cylinder block 2 is 3 provided with two aprons 1, flanges from one of the 4 aprons 1 can be extended to join with the opposite 5 side apron 1 to provide an additional area for 6 attachment of fan mountings and the like.

8 The apron 1 may be provided with a colour scheme as 9 required thereby dispensing with or reducing the 10 requirement to paint engine cylinder blocks and the 11 like following manufacture. An advantage of 12 employing a colour is that the paint finish quality 13 may be easily controlled, for example by using epoxy 14 paints. Moreover, pre-painted aprons can also be 15 employed with cylinder blocks 2 while aprons 1 formed 16 from sheet steel can be readily plated for show or 17 special finishes e.g. infra-red absorption, zinc, 18 chromium, gold and the like. Moreover, anodised 19 aluminium finishes can also be employed.

21 The apron 1 also serves to provide a surface for 22 printing corporate identification, end user 23 identification and other use instructions on an 24 engine employing screen-printing techniques and the 25 like. Alternatively, the apron 1 serves to provide a 26 good surface for application of adhesive labels and 27 the like to an engine.

29 Industrial Applicability

l The apron 1 of the invention encloses engine oil and 2 crankcase gases and functions, in combination with 3 the cylinder block 2, to provide a fluid reservoir 4 which serves as an engine oil capacitor to provide 5 extended engine service intervals. Oil within the 6 reservoir 11 is also connectively cooled.

8 As the reservoir does not replace, but is provided in 9 addition to, the sump, a conventional oil pumping 10 system may be utilised to circulate oil around the 11 engine. Further, as the oil feed from the reservoir 12 to the sump, via the crankcase, is generally provided 13 by a weir arrangement, no further pumps are required.

15 The velocity of the oil during engine operation is 16 slowed during its passage through the reservoir.

17 Accordingly, crankcase gases and other gases are able 18 to release from the relatively tranquil oil in the 19 reservoir 11 and pass upwards into an engine breather 20 system that will conventionally be provided at a 21 relatively high point in the engine.

23 The apron 1 of the invention also results in lower 24 manufacturing costs for cylinder blocks 2, and in 25 particular for cylinder blocks 2 requiring 26 customization, as side wall machining of the cylinder 27 blocks 2 to receive engine auxiliary components is 28 reduced or eliminated. The aprons 1 therefore 29 facilitate enhanced flexibility in cylinder block 30 design and manufacture. Moreover, the apron 1 of the

1 invention results in lower noise and vibration in 2 engines fitted with the apron 1.

4 The cylinder block 2 and the cylinder head are 5 provided with draining holes 17, 18 which allow oil 6 drain and crankcase gas interchange with the cylinder 7 head 20.

9 The apron 1 also facilitates the reduction or 10 elimination of tapped bosses and machined faces on 11 the sides of the cylinder block 2. The cylinder 12 block 2 can therefore be designed for minimal 13 machining operations while extended structures 14 normally needed to attach engine auxiliary components 15 can also be dispensed with. The apron 1 can be 16 employed with short block, deep skirt or ladder 17 constructions of cylinder block while the cylinder 18 block can be formed, in conventional manner, from 19 cast iron or aluminium or other suitable material.

20 The apron 1 can also facilitate engine transport and 21 handling. For example, the elongate beam 32 may be 22 adapted for engagement with forklift truck tines.

24 As indicated above, the apron 1 can be attached to 25 the cylinder head 20 employing low cost sheet metal 26 fastening methods such as the Flowform (Trade Mark) 27 process, weld nuts and studs, rivet nuts, self 28 tapping screws, rivets, edge clips and the like.

30 The apron 1 can be pre-assembled with some engine 31 auxiliary components in order to further increase

1 engine manufacture efficiency. Such components may 2 include electronics control units, harnesses, pipes, 3 brackets eta which can be pre-assembled with the 4 apron 1 as a sub-assembly on a side feeder to a main 5 assembly line. It will be appreciated by those 6 skilled in the art that shorter main assembly lines 7 serve to reduce work in progress and provide greater 8 flexibility and reduced costs.

10 The apron 1 mounted on a cylinder block 2 provides 11 additional structural stiffness to increase natural 12 bending/torsion frequencies and thereby reduce 13 transmitted noise and vibration to permit optimal 14 mounting designs.

16 The apron 1 provides application design flexibility 17 and facilitates customization of an engine. For 18 example, aprons 1 manufactured on adaptable 19 numerically controlled laser profilers, punches and 20 brake presses may be easily customized to customise 21 the cylinder block 2. Such equipment could be 22 located close to an assembly line to provide late 23 specification flexible manufacture of cylinder blocks

24 to provide a means for satisfying customer specific 25 requirements without excessive tooling costs or 26 disruption to base engine production. In effect, 27 engine mountings may be located at a desired location 28 on the apron 1 as required without significant 29 additional costs.

1 The invention is not limited to the embodiments 2 herein described which can be varied in construction 3 and detail.

Claims (12)

1 CLAIMS

3 1. A cylinder block assembly comprising: 4 a cylinder block; 5 a lubricating fluid sump; 6 a crankcase housing in the cylinder block; 7 an aperture in the crankcase housing; 8 an apron sealably mountable on the cylinder 9 block, and 10 a fluid reservoir defined between the apron and 11 the crankcase housing and adapted to receive 12 lubricating fluid, the fluid reservoir being 13 communicable with the crankcase housing through the 14 aperture.

16

2. A cylinder block assembly as claimed in Claim 1

17 wherein the cylinder block assembly includes a 18 cylinder head mounted on the cylinder block, said 19 cylinder head having at least one passage 20 communicable with the reservoir.

22

3. A cylinder block assembly as claimed in Claim 1 23 wherein the cylinder block assembly includes a 24 cylinder head mounted on the cylinder block and 25 wherein the apron includes mechanical attachment 26 points adapted to attach the apron to the cylinder 27 head.

29

4. A cylinder block assembly as claimed in any one 30 of Claims 1 to 3 wherein the apron includes an outer

1 surface, said outer surface having at least one 2 cooling element adapted to cool the fluid reservoir.

4

5. A cylinder block assembly as claimed in Claim 4 5 wherein the cooling element comprises a baffle 6 integrally formed in the apron.

8

6. A cylinder block assembly as claimed in any one 9 of Claims 1 to 5 further including a fluid passage 10 extending between the reservoir and the sump, which 11 fluid passage is dimensioned to effect a controlled 12 flow of lubricating fluid from the reservoir to the 13 sump.

15

7. A cylinder block assembly as claimed in any one 16 of Claims 1 to 6 wherein cylinder block has a side 17 wall and the apron is sealably mountable on the side 18 wall of the cylinder block, the side wall being 19 substantially non-machined.

21

8. An engine comprising a cylinder block assembly 22 as claimed in any of Claims 1 to 7.

24

9. An engine comprising: 25 a cylinder block; 26 a lubricating fluid sumpi 27 a crankcase housing in the cylinder block; 28 an apron sealably mounted on the cylinder block; 29 a fluid reservoir defined between the apron and 30 the crankcase housing) and

1 a fluid passage extending between the reservoir 2 and the crankcase housing) 3 wherein the fluid reservoir contains lubricating 4 fluid.

6

10. A method for lubricating an engine of the type 7 comprising: 8 a cylinder block; 9 a lubricating fluid sumpi 10 an apron sealably mounted on the cylinder block; 11 and 12 a lubricating fluid reservoir defined between 13 the cylinder block and the apron, 14 the method including the step of supplementing a 15 level of lubricating fluid in the sump with 16 lubricating fluid from the reservoir.

18

11. A cylinder block assembly substantially as 19 hereinbefore described with reference to the 20 drawings.

22

12. A method for lubricating an engine substantially 23 as hereinbefore described with reference to the 24 drawings.