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This is all getting fairly tedious, so here's my decision. I believe the issue is a combination of incompatable gasket design with the RS block and poor maching primarily on the head.
I cant see my car going in for a dealer tech to mangle for any as yet announced recall (which BTW I read was likely to not actually be anything more than a customer satisfaction action or some such thing and at the customers request, which is a sneaky way of Ford not admitting any issue but keeping customers that are worried happy)
No, mine will be undergoing regular boroscoping with my flex head boro which views the area of concern perfectly just as I have done for many many years on commercial jets. Look at the areas of degredation, and make a decision on continued operation.
If it shows signs of degredation I'll pull the head and do the gasket and check the head and block for flatness and finish. WCS I will need to pull the engine and get the block decked. Intermediate scenario, C gasket and get the head refinished (most likey outcome) best scenario (apart from no issues at all) is gasket only.
I'm far more comfortable with this than sending it to a dealer for them to pull the head. That gives me nightmares.

Ciao
No worries mate, it's such a rare problem I'm certain you won't ever be contacted by Ford's Re- Acquisition division like I just was to finalized the buy back of my RS. Why? Because it is more likely that the occurrence of a major failure requiring months to repair is so unlikely to happen to an RS that Australia doesn't even have a team to only deal with any replace or reimburse Southern Hemisphere residents. You Lucky Dogs!
 

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No worries mate, it's such a rare problem I'm certain you won't ever be contacted by Ford's Re- Acquisition division like I just was to finalized the buy back of my RS. Why? Because it is more likely that the occurrence of a major failure requiring months to repair is so unlikely to happen to an RS that Australia doesn't even have a team to only deal with any replace or reimburse Southern Hemisphere residents. You Lucky Dogs!
Yep thats us Aussies, lucky dogs:)

Ciao
 

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This is all getting fairly tedious, so here's my decision. I believe the issue is a combination of incompatable gasket design with the RS block and poor maching primarily on the head.
Very much agree with you that these two either by themselves or together are a major reason for most failures.

Bore bridge between 1-2 on mine looks like someone jackhammered the gasket area. The bore bridges between 2-3 and 3-4 are absolutely flawless looking.

Suspecting mine is finally starting to leak a little. Idle is getting a little jumpy and the car is starting to feel off beat. I'll take another look Sunday and see if any coolant is oozing into the chamber after sitting over night. It's supposed to be in the single digits temp wise.

Was hoping the gasket stays together until Ford lays out their official approach.
 

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Very much agree with you that these two either by themselves or together are a major reason for most failures.

Bore bridge between 1-2 on mine looks like someone jackhammered the gasket area. The bore bridges between 2-3 and 3-4 are absolutely flawless looking.

Suspecting mine is finally starting to leak a little. Idle is getting a little jumpy and the car is starting to feel off beat. I'll take another look Sunday and see if any coolant is oozing into the chamber after sitting over night. It's supposed to be in the single digits temp wise.

Was hoping the gasket stays together until Ford lays out their official approach.
Look forward to seeing the results, hopefully it will hang in there. My view forever is, if you want something done right then you need to do it yourself. That view gets reinforced every day.


Ciao
 

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Discussion Starter #2,488
An EB engine that has what looks to be a straightforward implementation of the bore bridge cooling and without any head gasket failures is the 1.6 EB.

Here you can see the slit (bridge) between the bores allowing coolant from the block to travel between the them.

Fiesta Bore Bridge Coolant Passage.JPG

Then you can see the headgasket sitting on the block. The bridge starts opposite to the circled opening in the gasket and coolant finds its way to this opening.

Fiesta Head Gasket Coolant Passage.JPG

And here on the head this opening lines up with the small hole in the head gasket allowing for the coolant to pass into the head cooling passage. This way the coolant can circulate from between the bridge past the gasket and into the head.

Fiesta Head Coolant Passage.JPG

However on the RS this is definitely not straight forward. Have a look at the images in article I posted some time ago and you can see that:

Blog : Focus RS Head Gasket Failure Mechanism : Stratified Automotive Controls

- There is no coolant passage between the cylinder bores that is visible at the gasket interface surface.
- There is no passage in the head for the coolant to flow through.

It almost looks like the original gasket design is supposed to allow coolant to enter on one side of the gasket (block to gasket interface) between the bores, hit the deadheaded hole and return back on its own on the other side (gasket to head interface).
 

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An EB engine that has what looks to be a straightforward implementation of the bore bridge cooling and without any head gasket failures is the 1.6 EB.

Here you can see the slit (bridge) between the bores allowing coolant from the block to travel between the them.

View attachment 246970

Then you can see the headgasket sitting on the block. The bridge starts opposite to the circled opening in the gasket and coolant finds its way to this opening.

View attachment 246978

And here on the head this opening lines up with the small hole in the head gasket allowing for the coolant to pass into the head cooling passage. This way the coolant can circulate from between the bridge past the gasket and into the head.

View attachment 246986

However on the RS this is definitely not straight forward. Have a look at the images in article I posted some time ago and you can see that:

Blog : Focus RS Head Gasket Failure Mechanism : Stratified Automotive Controls

- There is no coolant passage between the cylinder bores that is visible at the gasket interface surface.
- There is no passage in the head for the coolant to flow through.

It almost looks like the original gasket design is supposed to allow coolant to enter on one side of the gasket (block to gasket interface) between the bores, hit the deadheaded hole and return back on its own on the other side (gasket to head interface).
Thanks for the images Alex. I mentioned what is effectively a dead end cooling slot on the RS HG months ago and speculated that the coolant trapped in the gasket slot just super heats and probably cooks the gasket coating eventually because it has nowhere to flow through to.
Now we know that Ford penny pinched and used the unsuitable Mustang gasket in the RS and its bitten them on the arse in quite a few cases.

Ciao
 

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NEW ENGINE REQUIRED: Another Christmas without my RS. My car came off the production line on 23 July 2016. Picked it up in August 2016. Had a few months of very enjoyable motoring until the steering failed early December 2016. Took it to my dealer, only to learn that they had to order a complete steering rack from Germany. So first Christmas, where we had planned for a nice holiday in the baby, did not eventuate. Got the car back and had zero incidents till November this year. Then, I had the car idling in my daughter’s driveway and we were standing behind it when all of a sudden my daughter started complaining about stinging eyes. She then drew my attention to the car which was blowing white smoke from the exhaust. No, it was not the sweet smell of coolant, that I have read about in the forums, it was burning oil and my eyes were stinging also.

Took the car straight to my dealer and had it idling outside their service bay and it put on its show once again. (The movie is of the car at the dealers) So, in terms of symptons: No drop in coolant level, and no noticeable drop in oil level for that matter. I did have it over to Ford pretty smartly though so perhaps it didn’t get the opportunity to burn through too much.


So First report from dealer: Definitely burning oil. Compression test revealed loss of compression in one of the pots. It has been really hard to get an answer out of the dealer. The last time I spoke to the service manager (and I had to ring him), he told me that the car needed a new engine and that they were waiting for confirmation from Ford Australia. After the replacement engine was confirmed, I once again rang him and asked him how the engine in a vehicle with only 8000 kilometres on the clock, which is dead stock and has never done a track day, require replacing. He told me that the scope showed that the bore and the head were severely pitted. So that the best explanation I have. He also told me not to expect it over Christmas (again) and realistically expect it January some time.
 

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Look forward to seeing the results, hopefully it will hang in there. My view forever is, if you want something done right then you need to do it yourself. That view gets reinforced every day.


Ciao
Maybe you should invent a gasket heater so that you can pre-warm it so that it seals right away.
 

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It almost looks like the original gasket design is supposed to allow coolant to enter on one side of the gasket (block to gasket interface) between the bores, hit the deadheaded hole and return back on its own on the other side (gasket to head interface).
The gasket used in the RS is the same one found in the Mustang Ecoboost 2.3L up until the design change. Both the Mustang 2.3L and 1.6L use the top bore bridge cut groove for cooling. The RS uses inner bore drilled (cross or "x" drilled) which to me is a better design. You may want to read this patent from Ford on their cross drilled approach.

US 9470176 B2

Obviously the gasket design plays a critical role with how well these bore bridge cooling strategies work. The Mustang gasket has the same sized coolant passage openings on the gasket sides which should allow the same flow properties as their is no difference between the RS and late Mustang cylinder heads (maintains pressure drop needed for correct flow). It is now said the 2018 Mustangs use the same block as the RS so essentially the RS engine core is now in the 2018 Mustang.

Looks like Ford simply tried to save money by reusing the Mustang gasket on the RS. Then you add poor surface quality finish on the head and/or block in some cases and then you have a big problem. I don't believe coolant would boil in the deadheaded gasket coolant passage while the engine is running since the inner bore bridge cooling significantly reduces the bore bridge temperature according to patent posted above.
 

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Has anyone with an HG failure been given a reason for it other than block distortion? There is this post, this post and this post that talk about the problem being caused by a warped block.

From what I've read the RS block is metallurgically different from the 4 cylinder Mustang block. If there is no difference between the RS and Mustang head gaskets and cylinder heads, I think that points to the one thing that is different. The block. We know there was a bad run of blocks early on that lead to those blocks cracking. Could the HG issue be as simple as another run of bad blocks?
 

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Has anyone with an HG failure been given a reason for it other than block distortion? There is this post, this post and this post that talk about the problem being caused by a warped block.

From what I've read the RS block is metallurgically different from the 4 cylinder Mustang block. If there is no difference between the RS and Mustang head gaskets and cylinder heads, I think that points to the one thing that is different. The block. We know there was a bad run of blocks early on that lead to those blocks cracking. Could the HG issue be as simple as another run of bad blocks?
The head is different on the RS. They re-used the gasket from the Mustang however.
 

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I'll post the associated patent description here regarding the bore bridge cooling the RS uses. Claims section not posted here:

TECHNICAL FIELD

Various embodiments relate to cooling passages for a bore bridge between two cylinders in an internal combustion engine.

BACKGROUND

In a water-cooled engine, sufficient cooling may need to be provided to the bore bridge between adjacent engine cylinders. The bore bridge on the cylinder block and/or the cylinder head is a stressed area with little packaging space. In small, high output engines, due to packaging, the thermal and mechanical stresses may be increased. Higher bore bridge temperatures typically cause bore bridge materials to weaken and may reduce fatigue strength. Thermally weakened structure and thermal expansion of this zone may cause bore distortion that can be problematic to overall engine functionality such as, for example, piston scuffing, sealing functionality and durability of the piston-ring pack. Additionally, high temperatures at the bore bridge area also limit the reliability of the gasket in this zone, which in turn may cause combustion gas and coolant leaks, and/or reduced engine power output and overheating.

SUMMARY

In an embodiment, an internal combustion engine is provided with a cylinder block defining a block deck face, first and second cylinders, and a block cooling jacket. The first and second cylinders are adjacent to one another and separated by a block bore bridge. A cylinder head has a head deck face defining first and second chambers, and a head cooling jacket. The first and second chambers are adjacent to one another and separated by a head bore bridge. The first chamber and the first cylinder form a first combustion chamber, and the second chamber and the second cylinder form a second combustion chamber. A head gasket is positioned between the cylinder block and the cylinder head. The head gasket has a block side and a head side. The block cooling jacket has a first passage and a second passage intersecting the block deck face on either side of the block bore bridge. The first passage is on a first side of a longitudinal axis of the cylinder block. The head cooling jacket has a third passage and a fourth passage intersecting the head deck face on either side of the head bore bridge. The third passage is on the first side of the longitudinal axis of the cylinder block. The block bore bridge defines a bridge cooling passage extending from the first passage adjacent to the block deck face to the block deck face adjacent to the second passage. The head gasket is adapted to fluidly connect the first and fourth passages such that coolant flows from the first passage, through the bridge cooling passage, and to the fourth passage to cool the associated bore bridge.

In another embodiment, an engine is provided with a cylinder block having first and second passages intersecting a block face on opposed sides of a bore bridge defining a v-shaped passage. A cylinder head has third and fourth passages intersecting a head face, with the first and fourth passages being opposed. A gasket is placed between the block and the head. The gasket is adapted to fluidly connect the first and fourth passages via the v-shaped passage, and cover the second passage.

In yet another embodiment, a head gasket for an engine having a cooling jacket is provided. The gasket has a generally planar gasket body with a first side for cooperation with a cylinder head deck face, and a second side for cooperation with a cylinder block deck face. The gasket has a first aperture extending through the gasket body and adjacent to a cylinder block bore bridge. The first aperture fluidly connects a first cooling passage in a cylinder block and a second cooling passage in a cylinder head, with the first and second cooling passages being aligned. The gasket has a second aperture extending through the gasket body and adjacent to the cylinder block bore bridge. The second aperture fluidly connects a bridge cooling passage in the cylinder block bore bridge receiving fluid from the first passage and a third cooling passage in the cylinder head. The first and second apertures are spaced apart transversely on the gasket. The gasket body is adapted to cover a fourth passage in the cylinder block, with the fourth passage adjacent to the v-shaped passage.

Various embodiments of the present disclosure have associated, non-limiting advantages. For example, by providing a v-shaped passage or another passage across the bore bridge to provide coolant flow from a block cooling jacket to a head cooling jacket on an opposed side of a bore bridge, the bore bridge temperature, cylinder temperature, and relative cylinder vertical displacement may be reduced. A gasket fluidly connects the block cooling jacket and the head cooling jacket on a first side of the bore bridge. The bore bridge cooling passage is fluidly connected to the block jacket on the first side of the bridge and spaced apart from and fluidly disconnected from the block cooling jacket on the second, opposed side of the bore bridge. The gasket fluidly connects the bore bridge passage to the head cooling jacket on the second side of the bore bridge. The gasket covers the block cooling jacket on the second side of the bore bridge to prevent coolant flow from the block jacket to the head jacket on the second side of the bore bridge. The bore bridge cooling passage and head gasket provide for an increased pressure drop across the bore bridge, providing for increased coolant velocity and increased heat transfer of the bore bridge.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic of an engine configured to implement the disclosed embodiments;
FIG. 2 illustrates a schematic of cooling paths for a cooling jacket of a conventional engine;
FIG. 3 illustrates a schematic of cooling paths for a cooling jacket of the engine of FIG. 1 according to an embodiment;
FIG. 4 illustrates a perspective view of a cylinder block according to an embodiment;
FIG. 5 illustrates a graph of surface temperature around a cylinder bore and compares the cooling paths of the present disclosure to conventional engines;
FIG. 6 illustrates a graph of surface temperature as a function of bore length of a cylinder and compares the cooling paths of the present disclosure to conventional engines; and
FIG. 7 illustrates a graph of the vertical displacement of the bore edge relative to the in-cylinder lowest value around a cylinder bore and compares the cooling paths of the present disclosure to conventional engines.

DETAILED DESCRIPTION

As required, detailed embodiments of the present disclosure are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary and may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present disclosure.

FIG. 1 illustrates a schematic of an internal combustion engine 20. The engine 20 has a plurality of cylinders 22, and one cylinder is illustrated. The engine 20has a combustion chamber 24 associated with each cylinder 22. The cylinder 22 is formed by cylinder walls 32 and piston 34. The piston 34 is connected to a crankshaft 36. The combustion chamber 24 is in fluid communication with the intake manifold 38 and the exhaust manifold 40. An intake valve 42 controls flow from the intake manifold 38 into the combustion chamber 24. An exhaust valve 44 controls flow from the combustion chamber 24 to the exhaust manifold 40. The intake and exhaust valves 42, 44 may be operated in various ways as is known in the art to control the engine operation.

A fuel injector 46 delivers fuel from a fuel system directly into the combustion chamber 24 such that the engine is a direct injection engine. A low pressure or high pressure fuel injection system may be used with the engine 20, or a port injection system may be used in other examples. An ignition system includes a spark plug 48 that is controlled to provide energy in the form of a spark to ignite a fuel air mixture in the combustion chamber 24. In other embodiments, other fuel delivery systems and ignition systems or techniques may be used, including compression ignition.

The engine 20 includes a controller and various sensors configured to provide signals to the controller for use in controlling the air and fuel delivery to the engine, the ignition timing, the power and torque output from the engine, and the like. Engine sensors may include, but are not limited to, an oxygen sensor in the exhaust manifold 40, an engine coolant temperature, an accelerator pedal position sensor, an engine manifold pressure (MAP sensor, an engine position sensor for crankshaft position, an air mass sensor in the intake manifold 38, a throttle position sensor, and the like.

In some embodiments, the engine 20 is used as the sole prime mover in a vehicle, such as a conventional vehicle, or a stop-start vehicle. In other embodiments, the engine may be used in a hybrid vehicle where an additional prime mover, such as an electric machine, is available to provide additional power to propel the vehicle.

Each cylinder 22 may operate under a four-stroke cycle including an intake stroke, a compression stroke, an ignition stroke, and an exhaust stroke. In other embodiments, the engine may operate with a two stroke cycle. During the intake stroke, the intake valve 42 opens and the exhaust valve 44 closes while the piston 34 moves from the top of the cylinder 22 to the bottom of the cylinder 22 to introduce air from the intake manifold to the combustion chamber. The piston 34position at the top of the cylinder 22 is generally known as top dead center (TDC). The piston 34 position at the bottom of the cylinder is generally known as bottom dead center (BDC).

During the compression stroke, the intake and exhaust valves 42, 44 are closed. The piston 34 moves from the bottom towards the top of the cylinder 22 to compress the air within the combustion chamber 24.

Fuel is then introduced into the combustion chamber 24 and ignited. In the engine 20 shown, the fuel is injected into the chamber 24 and is then ignited using spark plug 48. In other examples, the fuel may be ignited using compression ignition.

During the expansion stroke, the ignited fuel air mixture in the combustion chamber 24 expands, thereby causing the piston 34 to move from the top of the cylinder 22 to the bottom of the cylinder 22. The movement of the piston 34 causes a corresponding movement in crankshaft 36 and provides for a mechanical torque output from the engine 20.

During the exhaust stroke, the intake valve 42 remains closed, and the exhaust valve 44 opens. The piston 34 moves from the bottom of the cylinder to the top of the cylinder 22 to remove the exhaust gases and combustion products from the combustion chamber 24 by reducing the volume of the chamber 24. The exhaust gases flow from the combustion cylinder 22 to the exhaust manifold 40 and to an after treatment system such as a catalytic converter.

The intake and exhaust valve 42, 44 positions and timing, as well as the fuel injection timing and ignition timing may be varied for the various engine strokes.

The engine 20 includes a cooling system 70 to remove heat from the engine 20. The amount of heat removed from the engine 20 may be controlled by a cooling system controller or the engine controller. The cooling system 70 may be integrated into the engine 20 as a cooling jacket. The cooling system 70 has one or more cooling circuits 72 that may contain water or another coolant as the working fluid. In one example, the cooling circuit 72 has a first cooling jacket 84 in the cylinder block 76 and a second cooling jacket 86 in the cylinder head 80 with the jackets 84, 86 in fluid communication with each other. The block 76 and the head 80 may have additional cooling jackets. Coolant, such as water, in the cooling circuit 72 and jackets 84, 86 flows from an area of high pressure towards an area of lower pressure.

The cooling system 70 has one or more pumps 74 that provide fluid in the circuit 72 to cooling passages in the cylinder block 76. The cooling system 70 may also include valves (not shown) to control to flow or pressure of coolant, or direct coolant within the system 70. The cooling passages in the cylinder block 76 may be adjacent to one or more of the combustion chambers 24 and cylinders 22, and the bore bridges formed between the cylinders 22. Similarly, the cooling passages in the cylinder head 80 may be adjacent to one or more of the combustion chambers 24 and cylinders 22, and the bore bridges formed between the combustion chambers 24. The cylinder head 80 is connected to the cylinder block 76to form the cylinders 22 and combustion chambers 24. A head gasket 78 in interposed between the cylinder block 76 and the cylinder head 80 to seal the cylinders 22. The gasket 78 may also have a slot, apertures, or the like to fluidly connect the jackets 84, 86, and selectively connect passages between the jackets 84, 86. Coolant flows from the cylinder head 80and out of the engine 20 to a radiator 82 or other heat exchanger where heat is transferred from the coolant to the environment.

FIG. 2 illustrates a conventional cross drill design for a bore bridge of the engine block. In other conventional engines, the bore bridge may have no cooling passages. FIG. 2 illustrates cooling paths across the bore bridge. The cylinder block 100of the engine is connected to the cylinder head 102 using a head gasket 104 to form a combustion chamber in the engine. The deck face 103 of the cylinder block 100 and the deck face 101 of the cylinder head 102 are in contact with first and second opposed sides of the gasket 104. The cylinder head 102 has bore bridges 106 between adjacent chambers. The block 100 has bore bridges 126 between adjacent cylinders.

Coolant flows from a block cooling jacket 130 to a head cooling jacket 150. The block jacket 130 has a passage 132 on the intake side of the engine and a passage 134 on the exhaust side of the engine. The head jacket 150 has a passage 152 on the intake side of the engine and a passage 154 on the exhaust side of the engine. The bore bridge 126 defines a conventional y-shaped cross drill passage 160 for cooling. The flow of coolant is illustrated in Figure by arrows. In an example of FIG. 2, a pressure drop across the bore bridge, or at the entrance to 160 from passage 132 and the exit of passage 160 to passage 134, is approximately 500 Pascals.

FIGS. 3-4 illustrate an example of the present disclosure. FIG. 3 illustrates a schematic of fluid flow across a bore bridge according an example of the present disclosure. FIG. 4 illustrates the cylinder block. Reference numerals in FIG. 2 may also be used with reference to FIGS. 3-5 for similar features.
The cooling system of FIG. 2 may be implemented on the engine illustrated in FIG. 1. FIG. 2 illustrates cooling paths across the cylinder block bore bridge. The cylinder block 100 of the engine is connected to the cylinder head 102 using a head gasket 104 to form a combustion chamber in the engine. The deck face 103 of the cylinder block 100 and the deck face 101 of the cylinder head 102 are in contact with first and second opposed sides of the gasket 104.

Between adjacent chambers in the cylinder head 102 are bore bridges 106. Between adjacent cylinders 124 in the block 100 are bore bridges 126. The chambers in the head 102 and the cylinders in the block 100 cooperate to form combustion chambers for the engine. The gasket 104 may include a bead on each side of the gasket and surrounding the chambers and cylinders to help seal the combustion chambers of the engine.

An embodiment of the engine block 100 is shown in FIG. 4 illustrating the longitudinal axis L and the transverse axis T of the engine, as well as the intake side I and the exhaust side E. Referring back to FIG. 3, coolant flows from a block cooling jacket 130 to a head cooling jacket 150. The block jacket 130 has a passage 132 on the intake side of the engine and a passage 134 on the exhaust side of the engine. Passages 132 and 134 intersect the block deck face 103. The head jacket 150 has a passage 152 on the intake side of the engine and a passage 154 on the exhaust side of the engine. Passages 152, 154 intersect the head deck face 101. The bore bridge 126 is a fluid barrier between passages 132, 134 and is adapted to prevent coolant from flowing directly from the passage 132 to the passage 134 and separate adjacent cylinders in the engine block 100.

The bore bridge 126 defines a v-shaped cross drill passage 170 for cooling. The flow of coolant is generally illustrated in FIG. 3 by arrows. In an example of FIG. 3, a pressure drop across the bore bridge, or at the entrance to 170 from passage 132 and the exit of passage 170 to passage 154, is approximately 8000 Pascals for the same operating conditions as described above with respect to FIG. 2, thereby providing approximately sixteen times greater pressure drop. An increased pressure difference provides a higher flow velocity, and associated higher heat transfer rates, in the bore bridge 126.

The v-shaped passage 170 has a first section of passage 172 and a second section of passage 174. The passage 172extends from the passage 132 adjacent to the block deck face 103 to an intermediate region 176 of the bore bridge 126. The passage 174 extends from and connects with the passage 172 in the intermediate region 176 of the bore bridge 126. The passage 174 intersects the block deck face 103 adjacent to and spaced apart from the passage 134.

Passage 172 is nonparallel with and intersects the passage 174. The passage 172 is oriented at an acute angle with the block deck face 103 as shown by angle a. The passage 174 is oriented at an acute angle with the block deck face 103 as shown by angle b. The angles a, b, may be the same as one another or may be different from one another. Similarly, the length and/or diameter of passages 172, 174 may be the same as one another or different than one another. The intermediate region 176 of the block bore bridge is spaced apart from the block deck face 103.

An end or exit 178 of the v-shaped passage intersects the block face 103 and is spaced apart from the passage 134. The exit 178 of the v-shaped passage may be aligned with the passage 154 of the head 102, or alternatively, the gasket 104may be slotted to provide a fluid connection between the exit 178 and the passage 154 as shown in FIG. 3. Another end, or the entrance 180 of the v-shaped passage intersects the cooling passage 152, and may be adjacent to the deck face 103.
Coolant in the block cooling jacket 130 flows from a passage 132 on the intake side, across bore bridge 126, and to a passage 154 in the cooling jacket 150 on the exhaust side of the cylinder head 102. The passage 154 is at a lower pressure than passage 132. Coolant in passage 132 also flows to passage 152 in the jacket 150. The gasket 104 isolates the passage 134 adjacent to the bore bridge, forcing passage 154 to receive coolant from the passage 170, thereby increasing flow across the bore bridge 126.

The head gasket 104 assists in providing the cooling paths as shown in FIG. 2. The gasket 104 has a generally planar gasket body that defines various apertures corresponding to bolt holes or other components of the engine. The gasket 104also has slots or apertures to form cooling passages to fluidly connect the jackets 130, 150. In one example, the gasket 104 is constructed from multiple layers, and each layer may be made from steel or another suitable material. One or more center layers 182 may be used as a spacer, and it may assist in determining the gasket thickness as well as provide a separating layer. The gasket has at least one upper layer 184 on the head side of the gasket 104. The gasket 104 also has at least one lower layer 186 on the block side of the gasket. The upper layer 184 cooperates with the cylinder head deck face 101, the lower layer 186 cooperates with the cylinder block deck face 103, and the intermediate layer 182 is positioned between the upper and lower layers.

The gasket 104 has a first aperture or slot 188 positioned between passage 132 and passage 152. The aperture 188 may be the same dimensions as the passages 132, 152, or may be smaller in size to restrict flow. The gasket has a second aperture or slot 190 positioned between the exit 178 of the v-shaped passage 170 and the passage 154. The slots 188, 190 may be formed by stamping the layers of the gasket, or by another process as is known in the art. Each slot is positioned between adjacent beads of the gasket. The slots or apertures 188, 190 may be formed by selectively removing gasket material from one or more layers to form a coolant path from the block to the head. Slots may be provided in each layer of the gasket that cooperate to form the coolant path across the gasket, and slots in different layers may be the same length, different lengths, and may be aligned or offset to provide the desired coolant flow pattern. The apertures 188, 190are spaced apart transversely along the T axis on the gasket.

At least one layer of the gasket 104, such as layer 186, covers the passage 134 at the deck face to prevent flow from the passage 134 to the passage 154 adjacent to the bore bridge 126. Therefore, in the region of the bore bridge 126, passages 132, 152, 170, and 154 are in direct fluid communication, and passage 134 is blocked or fluidly disconnected.

The perimeter of the apertures 188, 190 may be generally triangular, circular, or another shape to correspond with perimeters of associated passages. In some examples, the cross sectional area of the apertures 188, 190 corresponds with the cross sectional area of at least one or the associated passages taken along the deck face to prevent flow restrictions. In other examples, the cross sectional area of the apertures 188, 190 is less than the cross sectional area of at least one or the associated passages taken along the deck face to provide a flow restriction to control flow. The apertures 188, 190 may also have a diverging cross sectional area or a converging cross sectional area across the gasket 104 to control flow, for example, to control a fluid streamline.

Although the coolant is described as flowing from the intake side of the engine to the exhaust side, in other embodiments, the coolant may flow in the opposite direction, i.e. from the exhaust side to the intake side, and the v-shaped passage 170may be reversed.

Coolant flow through the engine is generally shown by the arrows in FIG. 3. The gasket 104 may provide a coolant flow path from the block 100 to the head 102 through the bore bridge 126. The gasket 104 may provide a barrier at passage 134, thereby causing the coolant to flow transversely from an intake side to an exhaust side of the engine across the bore bridge.

Coolant in the cylinder head passages in the block deck face may travel along a longitudinal axis or longitudinal direction L of the engine such that coolant is provided to the cylinders in a sequential manner.

FIG. 4 illustrates a partial top perspective view of a cylinder block 100 employing an embodiment of the present disclosure. The cylinder block 100 may be cast out of a suitable material such as aluminum. The cylinder block 100 is a component in an in-line four cylinder engine, although other engine configurations may also be used with the present disclosure. The cylinder block 100 has a deck face 103 or top face that forms cylinders 124. The deck face 103 may be formed to provide a semi-open deck design as illustrated. Each cylinder 124 cooperates with a corresponding chamber in the head 102 to form the combustion chamber. Each cylinder 124 has an exhaust side E that corresponds to the side of the head with the exhaust ports, and an intake side I that corresponds to the side of the head with the intake ports. Various passages are also provided on the deck face 103 and within the cylinder block 100 that form a cooling jacket 130 for the cylinder block and engine. The cooling jacket 130 may cooperate with corresponding ports associated with a head cooling jacket to form an overall cooling jacket for the engine. Coolant in the cylinder block passages in the block deck face may travel along a longitudinal axis or longitudinal direction L as shown by the arrow in FIG. 4 of the engine such that coolant is provided to the cylinders in a sequential manner.

A bore bridge 126 is formed between a pair of cylinders 124. The bore bridge 126 may require cooling with engine operation as the temperature of the bridge 126 may increase due to conduction heating from hot exhaust gases in the combustion chamber. The exit 178 of a v-shaped passage 170 is illustrated and is adjacent to and spaced apart from the passage 134. The exit 178 intersects the deck face 103.

FIGS. 5-7 illustrate modeling results comparing an engine without a bore bridge cooing passage, an engine with a bore bridge cooling passage according to FIG. 2, and a bore bridge cooling passage 170 according to FIG. 3 and the present disclosure. The results were calculated for the number three cylinder in the engine, which encounters the greatest heating and/or displacement of the engine bore bridges. Generally, the Figures show that the passage 170 provides a high pressure drop across the passage 170 which increases the coolant flow and heat transfer significantly. The passage 170 reduces bore bridge temperature, reduces the temperature and displacement gradient around the bore edge, and reduces bore wall temperature along the bore length. In one example, a temperature of the bore bridge and a maximum block temperature using a passage 170 are reduced by approximately thirty degrees Celsius compared to an engine with no bore bridge cooling passage. For comparison, a temperature of the bore bridge and a maximum block temperature using a passage 160 are reduced by approximately ten degrees Celsius compared to an engine with no bore bridge cooling passage.

FIG. 5 illustrates a surface temperature around a cylinder bore adjacent to the deck face 103. The surface temperature is plotted as a function of angle in degrees around the cylinder. The longitudinal axis of the engine, or the center of the bore bridges, is at 90 degrees and 270 degrees. The temperature of the cylinder bore with no bore bridge cooling passages is shown by line 200, and the temperature peaks at the angular position associated with the bore bridges. The temperature of the cylinder bore with cooling passages 160 in the bore bridges as shown in FIG. 2 is shown by line 202, which provides some temperature relief compared to line 200. The temperature of the cylinder bore with cooling passages 170 in the bore bridges as shown in FIG. 3 according to the present disclosure are shown by line 204, which provides significant temperature relief compared to lines 200 and 202.

FIG. 6 illustrates a surface temperature of a cylinder bore as a function of bore length, with increasing bore depth away from the deck face. In FIG. 6, a distance of zero is associated with the deck face 103 of an engine block. The surface temperature was calculated for the cylinder bore at an angular position of 90 degrees as described with respect to FIG. 5along a bore bridge. The longitudinal axis of the engine, or the center of the bore bridge, is at 90 degrees. The temperature of the cylinder bore with no bore bridge cooling passages is shown by line 210, and the temperature peaks at the deck face 103. The temperature of the cylinder bore with cooling passages 160 in the bore bridges as shown in FIG. 2is shown by line 212, which provides some temperature relief compared to line 210. The dip at 214 may be attributed to the lower passage connecting to passage 134 in FIG. 2. The temperature of the cylinder bore with cooling passages 170in the bore bridges as shown in FIG. 3 according to the present disclosure are shown by line 216, which provides improved temperature relief compared to lines 210 and 212 adjacent to the deck face 103.

FIG. 7 illustrates a graph of the vertical displacement of the bore edge relative to the in-cylinder lowest value around a cylinder bore. The relative vertical displacement is determined by subtracting the minimum vertical displacement for the cylinder from the vertical displacement curve around the cylinder. The relative vertical displacement is plotted as a function of angle in degrees around the cylinder. The longitudinal axis of the engine, or the center of the bore bridges, is at 90 degrees and 270 degrees. The relative vertical displacement is greatest at the bore bridges due to the increased temperature of the bore bridges and associated thermal expansion. The relative vertical displacement of the cylinder bore with no bore bridge cooling passages is shown by line 220. The relative vertical displacement of the cylinder bore with cooling passages 160 in the bore bridges as shown in FIG. 2 is shown by line 222, which provides some vertical displacement relief compared to line 220. The vertical displacement of the cylinder bore with cooling passages 170 in the bore bridges as shown in FIG. 3 according to the present disclosure are shown by line 224, which provides improved vertical displacement relief compared to lines 220 and 222.

Various embodiments of the present disclosure have associated, non-limiting advantages. For example, by providing a v-shaped passage or another passage across the bore bridge to provide coolant flow from a block cooling jacket to a head cooling jacket on an opposed side of a bore bridge, the bore bridge temperature, cylinder temperature, and relative cylinder vertical displacement may be reduced. A gasket fluidly connects the block cooling jacket and the head cooling jacket on a first side of the bore bridge. The bore bridge cooling passage is fluidly connected to the block jacket on the first side of the bridge and spaced apart from and fluidly disconnected from the block cooling jacket on the second, opposed side of the bore bridge. The gasket fluidly connects the bore bridge passage to the head cooling jacket on the second side of the bore bridge. The gasket covers the block cooling jacket on the second side of the bore bridge to prevent coolant flow from the block jacket to the head jacket on the second side of the bore bridge. The bore bridge cooling passage and head gasket provide for an increased pressure drop across the bore bridge, providing for increased coolant velocity and increased heat transfer of the bore bridge.

While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the present disclosure. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the disclosure. Additionally, the features of various implementing embodiments may be combined to form further embodiments.

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Ford has had my RS two nights

As expected, it passed the leakdown test

My service man is telling me he wants to try to dig a bit deeper. He mentioned he saw some "recall" on Facebook, but has checked my vin and doesn't see it.

I think he is just talking about all the chatter we are doing.

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