New Lindsey product hmmm
10-22-2005, 11:34 PM
#1
Burning Brakes
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New Lindsey product hmmm
This looks interesting but I'm not sure if it's worth the effort. Too bad I just finished torqueing the head back on, but then my finances are extremely tight anyway.
What do you guys think? My gasket failed on cyl. #4 due to severe deformation, rather than burn-thru. The other cyls were a bit deformed but had not failed.
What do you guys think? My gasket failed on cyl. #4 due to severe deformation, rather than burn-thru. The other cyls were a bit deformed but had not failed.
10-22-2005, 11:55 PM
#5
Three Wheelin'
It helps cool the head, which helps prevent detonation, which helps prevent blown headgaskets. I dont know why they mention that no cars with this modification have seen headgasket problems, that is misleading, since they just begain doing this, and it wont be true for long. But for the money I think this is one of the best modifications one can do to the 951.
I still say the #1 cause of headgasket failures is running lean and hot combustion burning through. Until you start making big hp, when the cylinders start to move around in the casting and that causes the headgasket problem.
I still say the #1 cause of headgasket failures is running lean and hot combustion burning through. Until you start making big hp, when the cylinders start to move around in the casting and that causes the headgasket problem.
10-23-2005, 01:19 AM
#6
My gosh are they kidding. Has any one look at the water passages in the MLS gasket. Most engines force the water thro the block, and back up into the head from the rear. The 944 is the same. The MLS gasket increases the restriction in the front cylinders amking more of the water to be forced up from the rear. If they are still selling the old style Gasket, they probably have not seen whats new and available.
Purging air from Cylinder Heads is a normal thing for any good engine builder. Especially with a Turbo engine. Whats more typical is a restrictor in the water out pipe. This way, backpressure is added to the water system in the head, forcing the water to be pushed into all of the water passages. This also purges all of the air out. I have seen on racing engines where the water is directed into the head as well as into the block from the pump. I have also seen where a line is fitted into the head to bleed off the steam back into the Header tank. The M42 race engine was like this. The difference is that these engines run large external water pumps, where water pressure and volume are alot higher than a stock 944 pump. The stock pump needs all the help it can get. Adding a restrictor helps increase the pumps efficency. Adding a bleed only allows less water to circulate within the Head. Same system pressure but less volume. What you are wanting is an increase in head pressure. adding this little mod will only lower the head pressure. If steam is created there, this will not stop it from happening. Only water will do that. I'd be careful about running less water thro' the head. I know many 944 turbo race engines that are running a restrictor in the system. This mod works and can be added without pulling the engine apart. Fits into the water out pipe. easy. Takes 2 mins to fit.
Their mod, probably won't hurt you, but don't expect it to help either.
Purging air from Cylinder Heads is a normal thing for any good engine builder. Especially with a Turbo engine. Whats more typical is a restrictor in the water out pipe. This way, backpressure is added to the water system in the head, forcing the water to be pushed into all of the water passages. This also purges all of the air out. I have seen on racing engines where the water is directed into the head as well as into the block from the pump. I have also seen where a line is fitted into the head to bleed off the steam back into the Header tank. The M42 race engine was like this. The difference is that these engines run large external water pumps, where water pressure and volume are alot higher than a stock 944 pump. The stock pump needs all the help it can get. Adding a restrictor helps increase the pumps efficency. Adding a bleed only allows less water to circulate within the Head. Same system pressure but less volume. What you are wanting is an increase in head pressure. adding this little mod will only lower the head pressure. If steam is created there, this will not stop it from happening. Only water will do that. I'd be careful about running less water thro' the head. I know many 944 turbo race engines that are running a restrictor in the system. This mod works and can be added without pulling the engine apart. Fits into the water out pipe. easy. Takes 2 mins to fit.
Their mod, probably won't hurt you, but don't expect it to help either.
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10-23-2005, 01:49 AM
#8
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I find that very interesting and useful info too. I'm tempted to go out and find a restricter to use, as I am quite conscious about my cooling system. Please let us know how we can do this.
~Eyal
~Eyal
Last edited by Eyal 951; 10-23-2005 at 02:23 AM.
10-23-2005, 03:46 AM
#9
Rennlist Member
This is what I understand from the explaination I was given...
While looking for causes for so many failures in the same spot on #4, a pocket in the coolant passages in the head was discovered that does not flow. That pocket is located right where the majority of failures occured. Increasing overall pressure or flow through the head does not create flow in the pocket. Because of the lack of flow in that pocket the coolant boils creating steam. Steam does not cool very well and creates a hot spot that eventualy causes deformation and failure. The vent kit has a very small hole that allows the steam to be vented out of the pocket and away from the head without reducing much of the coolant flow through the rest of the head.
The vent line in the kit is clear. When the car is running at idle you can see coolant in the vent line. When the car is warmed up and reving at higher rpms you can see the steam bubbles travelling through the line back to the coolant tank.
While looking for causes for so many failures in the same spot on #4, a pocket in the coolant passages in the head was discovered that does not flow. That pocket is located right where the majority of failures occured. Increasing overall pressure or flow through the head does not create flow in the pocket. Because of the lack of flow in that pocket the coolant boils creating steam. Steam does not cool very well and creates a hot spot that eventualy causes deformation and failure. The vent kit has a very small hole that allows the steam to be vented out of the pocket and away from the head without reducing much of the coolant flow through the rest of the head.
The vent line in the kit is clear. When the car is running at idle you can see coolant in the vent line. When the car is warmed up and reving at higher rpms you can see the steam bubbles travelling through the line back to the coolant tank.
10-23-2005, 01:48 PM
#10
Three Wheelin'
mr2racer, where is the chart for the stock water pump? How do you know it needs all the help it can get? I disagree about the restrictor, it is lowering volume flow, which is a goal of the cooling system in the head. As long as there is water making it everywhere in the head (which it is with the steam vents), the only thing you can do to improve cooling is to move it around faster. Increasing pressure is not necessary as long as the flow is there. Water absorbs a lot of heat when it vaporizes, you just need to move the steam the hell out of there after it happens.
The MLS gasket is a better design, yes.
Please explain how raising backpressure purges the steam out.
The MLS gasket is a better design, yes.
Please explain how raising backpressure purges the steam out.
10-23-2005, 02:32 PM
#11
"Increasing overall pressure or flow through the head does not create flow in the pocket"
WRONG!!!
"How do you know it needs all the help it can get? I disagree about the restrictor, it is lowering volume flow, which is a goal of the cooling system in the head."
All engines need more water pump. Or it could be said, "you can never have enough water pump" or even, too much water pump will never hurt" Ask an engine builder what he thinks. I'll bet you he'll agree.
The goal of the water system is too remove heat from the head and block. To do this you need to force the water all around the passages, around the back of the valve seats etc, removing all of the heat. Adding a restrictor in the water out increases the head and block pressure, not the system pressure. Adding pressure in the head and Block forces the water to go places it may not go under normal head and block pressure. The "normal" pressure would be the pressure crreated by the existing head Gasket and Head ports. Often when performance is increased and temperatures are raised, more pressure is required to purge the heat spots out.
So to answer your question, backpressure forces the water into the places where steam is created. If water fills the cavity, steam will not. This is engine building 101. I am not telling something that is not widely known and done. This is as common as dirt in the engine building business.
WRONG!!!
"How do you know it needs all the help it can get? I disagree about the restrictor, it is lowering volume flow, which is a goal of the cooling system in the head."
All engines need more water pump. Or it could be said, "you can never have enough water pump" or even, too much water pump will never hurt" Ask an engine builder what he thinks. I'll bet you he'll agree.
The goal of the water system is too remove heat from the head and block. To do this you need to force the water all around the passages, around the back of the valve seats etc, removing all of the heat. Adding a restrictor in the water out increases the head and block pressure, not the system pressure. Adding pressure in the head and Block forces the water to go places it may not go under normal head and block pressure. The "normal" pressure would be the pressure crreated by the existing head Gasket and Head ports. Often when performance is increased and temperatures are raised, more pressure is required to purge the heat spots out.
So to answer your question, backpressure forces the water into the places where steam is created. If water fills the cavity, steam will not. This is engine building 101. I am not telling something that is not widely known and done. This is as common as dirt in the engine building business.
10-23-2005, 08:09 PM
#12
Rennlist Member
Lets see, put a tee in the coolant system and run the one line to a sealed jar. Remove the air from the system including the jar.
The jar though connected to the system does not exchange coolant with the system at flow, it only has the one line going to the system.
You are telling me if I increase the system pressure near where the jar connects to the system it will somehow cause the coolant in my jar to circulate with the rest of the coolant in the system? I think not.
Now, If I heat my jar so the coolant boils it creates a steam pocket or bubble in the jar. Increasing the pressure in the system does not magically flush the steam bubble out of the jar, remember there is no flow through the jar. Instead it merely increases the pressure of the steam bubble along with the coolant.
The pocket that was discovered acts like this jar.
Increasing the pressure increases the boiling point to try to reduce the steam pockets from being created in the first place not to increase the flow to areas that don't flow well.
The jar though connected to the system does not exchange coolant with the system at flow, it only has the one line going to the system.
You are telling me if I increase the system pressure near where the jar connects to the system it will somehow cause the coolant in my jar to circulate with the rest of the coolant in the system? I think not.
Now, If I heat my jar so the coolant boils it creates a steam pocket or bubble in the jar. Increasing the pressure in the system does not magically flush the steam bubble out of the jar, remember there is no flow through the jar. Instead it merely increases the pressure of the steam bubble along with the coolant.
The pocket that was discovered acts like this jar.
Increasing the pressure increases the boiling point to try to reduce the steam pockets from being created in the first place not to increase the flow to areas that don't flow well.
Last edited by RKD in OKC; 10-23-2005 at 08:28 PM.
10-23-2005, 11:27 PM
#13
"Lets see, put a tee in the coolant system and run the one line to a sealed jar. Remove the air from the system including the jar."
That won't work. How do expect anything to be get into the "jar" if the jar cannot vent the air in the jar?
Either i am mis understanding what you are saying, or you have no idea what I am saying.
You can connect all the jars you like, but if you do not vent them, nothing will flow into them. Boil them all you like too.
To stop steam pockets from forming and to remove the heat from that area, you need coolant. Vent the steam removes the air pocket but does not necessarily mean the coolant will fill the cavity. Pressure will do this typically. Don't get confused with system pressure. That is set by the cap you run. The block pressure is set by the Head Gasket and the head pressure is set by the water outlet size. restrict the water outlet and up goes the head pressure, forcing the coolant into the cavity where you say air gets trapped. I understand that sometimes air can get trapped, but in the case of the 944 head, the higher Cylinder Head pressure works great and at the same time helps the rest of the Head cooling as well.
"The jar though connected to the system does not exchange coolant with the system at flow, it only has the one line going to the system"
That is correct. Without the ability to vent, your jar will do nothing.
"You are telling me if I increase the system pressure near where the jar connects to the system it will somehow cause the coolant in my jar to circulate with the rest of the coolant in the system? I think not."
You do not understand the difference between system and head pressure. whatever line you attach, this line needs to flow coolant back to the header tank. The header tank needs to be the only place a pocket of air is present in the whole coolant system. Otherwise you have not removed the air!!
"The pocket that was discovered acts like this jar.
Absolutely correct. Unless you allow the air to vent, or replace the air with coolant, you are correct.
"Increasing the pressure increases the boiling point to try to reduce the steam pockets from being created in the first place not to increase the flow to areas that don't flow well"
Absolutely wrong. Increasing the system pressure increases the systems boiling point. Steam pockets are created regardless of the system pressure. Some heads that run lower system pressures do not have pockets of steam, whereas others that run higher system pressure often do. Head pressure or backpressure within the Cylinder head does increase the flow into area that don;t flow that well. Why do you think the holes in aftermarket Gaskets and the outlet sizes on aftermarket pumps are like they are. Take a look at many racing cylinder Heads. They often have the water passages going from side to side, not back to front. This helps the head to purge the air out and on the outlet side they usually have removeable restrictors that fit inside the head and connect to a manifold that runs the length of the head. Porsche even do this on their racing heads. Very common stuff. But on street production Heads where the water goes from back to front, the common fix is to increase the head pressure by increasing the backpressure.
That won't work. How do expect anything to be get into the "jar" if the jar cannot vent the air in the jar?
Either i am mis understanding what you are saying, or you have no idea what I am saying.
You can connect all the jars you like, but if you do not vent them, nothing will flow into them. Boil them all you like too.
To stop steam pockets from forming and to remove the heat from that area, you need coolant. Vent the steam removes the air pocket but does not necessarily mean the coolant will fill the cavity. Pressure will do this typically. Don't get confused with system pressure. That is set by the cap you run. The block pressure is set by the Head Gasket and the head pressure is set by the water outlet size. restrict the water outlet and up goes the head pressure, forcing the coolant into the cavity where you say air gets trapped. I understand that sometimes air can get trapped, but in the case of the 944 head, the higher Cylinder Head pressure works great and at the same time helps the rest of the Head cooling as well.
"The jar though connected to the system does not exchange coolant with the system at flow, it only has the one line going to the system"
That is correct. Without the ability to vent, your jar will do nothing.
"You are telling me if I increase the system pressure near where the jar connects to the system it will somehow cause the coolant in my jar to circulate with the rest of the coolant in the system? I think not."
You do not understand the difference between system and head pressure. whatever line you attach, this line needs to flow coolant back to the header tank. The header tank needs to be the only place a pocket of air is present in the whole coolant system. Otherwise you have not removed the air!!
"The pocket that was discovered acts like this jar.
Absolutely correct. Unless you allow the air to vent, or replace the air with coolant, you are correct.
"Increasing the pressure increases the boiling point to try to reduce the steam pockets from being created in the first place not to increase the flow to areas that don't flow well"
Absolutely wrong. Increasing the system pressure increases the systems boiling point. Steam pockets are created regardless of the system pressure. Some heads that run lower system pressures do not have pockets of steam, whereas others that run higher system pressure often do. Head pressure or backpressure within the Cylinder head does increase the flow into area that don;t flow that well. Why do you think the holes in aftermarket Gaskets and the outlet sizes on aftermarket pumps are like they are. Take a look at many racing cylinder Heads. They often have the water passages going from side to side, not back to front. This helps the head to purge the air out and on the outlet side they usually have removeable restrictors that fit inside the head and connect to a manifold that runs the length of the head. Porsche even do this on their racing heads. Very common stuff. But on street production Heads where the water goes from back to front, the common fix is to increase the head pressure by increasing the backpressure.
10-24-2005, 01:08 AM
#14
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"To stop steam pockets from forming and to remove the heat from that area, you need coolant. Vent the steam removes the air pocket but does not necessarily mean the coolant will fill the cavity. Pressure will do this typically. Don't get confused with system pressure. That is set by the cap you run. The block pressure is set by the Head Gasket and the head pressure is set by the water outlet size. restrict the water outlet and up goes the head pressure, forcing the coolant into the cavity where you say air gets trapped. I understand that sometimes air can get trapped, but in the case of the 944 head, the higher Cylinder Head pressure works great and at the same time helps the rest of the Head cooling as well."
I'm confused, not trying to get into this, as it's a bit over my head, but I have a question.
If a gas, that is holding its space by pressurized displacement, is then vented or removed form the space, would fluid naturally fill this space. The only thing keeping it out of this space is the greater pressure of the steam as opposed to the fluid right? Remove the steam and create a space to fill. Now I couls d see a need, once vented to provide a greater volume of fluid to fill the space. Is this what you are trying to accomplish by adding a restriction? If this isn't the case then i need to get a much better handle on how I didn't die in the two submarines that I rode in.
I'm confused, not trying to get into this, as it's a bit over my head, but I have a question.
If a gas, that is holding its space by pressurized displacement, is then vented or removed form the space, would fluid naturally fill this space. The only thing keeping it out of this space is the greater pressure of the steam as opposed to the fluid right? Remove the steam and create a space to fill. Now I couls d see a need, once vented to provide a greater volume of fluid to fill the space. Is this what you are trying to accomplish by adding a restriction? If this isn't the case then i need to get a much better handle on how I didn't die in the two submarines that I rode in.
10-24-2005, 01:38 AM
#15
Exactly. And by adding the restriction, you are creating backpressure, which forces the coolant into the pocket. You also force the coolant around all areas of the head. Venting the air will allow the coolant to go there, but running a higher head pressure is a far better way of purging the air and helping the whole head.
I have read the bit on the LR web site. Do they really expect people to go along with what is written. "The pressure built up in this pocket pushes out the Gasket". I have seen blown Gaskets caused by the heads distorting from temperature, but never from the pressure. You learn something everyday.
I have read the bit on the LR web site. Do they really expect people to go along with what is written. "The pressure built up in this pocket pushes out the Gasket". I have seen blown Gaskets caused by the heads distorting from temperature, but never from the pressure. You learn something everyday.