water dosent compress

[AdrianGQ]

have a 95 patrol coil cab td42 with after market turbo and drouned it a couple of months ago- result a bent conrod in no 4 and a cracked head bore looks ok as dose pistons rings ect ect so i will just replace the rod but i dont know wether to replace head with new or second hand have been quoted $1150 for bear head is this ok
[/list]

[dumbdunce]

that is about the right price for a new bare head. Is your motor fully disassembled and have you measured all the other rods for bend, twist and length? and checked all the pistons for cracks? is the crack in the head proper or only in the precombustion chamber?

[plowy]

i agree dumbdunce you do a half arse job its probably come back n bight you in the arse n cost you twice as much the first time round

do it right the first time adrian n save youreself alot of heart ache n $

[Shadow]

actually water does compress but only a very tiny amount and only when subjected to many thousands of tonns of pressure (ie bottom of ocean).

[Busiboy]

actually water does compress but only a very tiny amount and only when subjected to many thousands of tonns of pressure (ie bottom of ocean).

He's right to a degree, water compresses any where though, you can do it with a syringe and your finger, just doesn't compress very much at all, under 1 - 5%-ish me thinks.

Also I would go with DD, I doubt the head is the worst of your concerns, I would be doing a lot more than replacing one stuffed conrod.

[MY45]

actually water does compress but only a very tiny amount and only when subjected to many thousands of tonns of pressure (ie bottom of ocean).

He's right to a degree, water compresses any where though, you can do it with a syringe and your finger, just doesn't compress very much at all, under 1 - 5%-ish me thinks.

Also I would go with DD, I doubt the head is the worst of your concerns, I would be doing a lot more than replacing one stuffed conrod.

And at 6000rpm through a bog hole it doesnt take long to compress it that 5%

[-Scott-]

Trivia alert!

Early prop-driven fighter planes had a mechanism to synchronise the machine guns to fire between the propeller blades - i.e. the blades pass in front of the barrel. The mechanism was designed based on the theory that liquid does compress.

I don't understand what would happen to the plane if liquid doesn't compress...

Scott

[muzza_fattire]

I don't understand what would happen to the plane if liquid doesn't compress...

I would hate to think what would happen to your cars hydraulic brakes if liquid did compress

[-Scott-]

I don't understand what would happen to the plane if liquid doesn't compress...

I would hate to think what would happen to your cars hydraulic brakes if liquid did compress

If the compression is small enough, probably no more that happens now as the brake hoses expand with pressure.

[muzza_fattire]

I don't understand what would happen to the plane if liquid doesn't compress...

I would hate to think what would happen to your cars hydraulic brakes if liquid did compress

If the compression is small enough, probably no more that happens now as the brake hoses expand with pressure.

I think we need more information on the theory behind the planes mechanism...

[-Scott-]

I don't understand what would happen to the plane if liquid doesn't compress...

I would hate to think what would happen to your cars hydraulic brakes if liquid did compress

If the compression is small enough, probably no more that happens now as the brake hoses expand with pressure.

I think we need more information on the theory behind the planes mechanism...

Yep!

["CANADA"]

its only the oxygen in the water that compresses

[-Scott-]

its only the oxygen in the water that compresses

Are you sure? I would expect hydrogen, being less dense (Hindenberg etc.) would compress more readily.

[djr320kw]

Hey guys you are talking about different types of liquid. Water is different to brake fluid. That is why they dont use water in brake lines.

As for the fighter plane mechanism. I have seen that on discovery or history channel the other week. I didnt think it was a liquid that did it but could be wrong.

[bogged]

http://www.physlink.com/Education/AskExperts/ae15.cfm


Can you compress a liquid (water)?
Asked by: Guy Matthews

Answer
The answer is yes, You can compress water, or almost any material. However, it requires a great deal of pressure to accomplish a little compression. For that reason, liquids and solids are sometimes referred to as being incompressible.

To understand what happens, remember that all matter is composed of a collection of atoms. Even though matter seems to be very solid, in actuality, the atoms are relative far apart, and matter is mostly empty space. However, due to the forces between the molecules, they strongly resist being pressed closer together, but they can be. You probably have experienced compressing something as hard as steel. Have you ever bounced a steel ball bearing off a sidewalk? When you do that, the 'bounce' is due to compressing the steel ball, just a tiny little spot that comes into contact with the sidewalk. It compresses and then springs back, causing the bounce.

The water at the bottom of the ocean is compressed by the weight of the water above it all the way to the surface, and is more dense than the water at the surface.

A consequence of compressing a fluid is that the viscosity, that is the resistance of the fluid to flow, also increases as the density increases. This is because the atoms are forced closer together, and thus cannot slip by each other as easily as they can when the fluid is at atmospheric pressure.

[Shadow]

Trivia alert!

Early prop-driven fighter planes had a mechanism to synchronise the machine guns to fire between the propeller blades - i.e. the blades pass in front of the barrel. The mechanism was designed based on the theory that liquid does compress.

I don't understand what would happen to the plane if liquid doesn't compress...

Scott

I dont think anything mounted on a plane could compress water enough to be noticeable or measureable.

For almost all scientific experiments water is considered incompressible as the amount it actually compresses by anything they use in a laboratory is unmeasureable.

You can pressurise water very easily, but the pressure is not created from the water compressing, rather the container expanding (stretching)around it. This is what Adrians engine did when he flooded the engine bay

[bogged]

Trivia alert!

Early prop-driven fighter planes had a mechanism to synchronise the machine guns to fire between the propeller blades - i.e. the blades pass in front of the barrel. The mechanism was designed based on the theory that liquid does compress.
Scott

Been tryin to find some info on this, but most I can find says they were Cam driven between the prop shaft, and the gun... no mention of water yet...

[Shadow]

There is no mystery about a machine gun firing through a propeller without hitting the blades. Nearly everyone understands the principle by which the valves of a gasoline motor are timed so as to open and close at a given point in the revolution of the engine. In the same way a machine hgun may be timed to shoot. On the end of the cam shaft of the motor is plaved an additional cam. Next to this is a rod connected with the breech block of the gun. When the gun is not being fired the rod is held away from the cam by a spring. pressing the trigger brings the two in contact , and each time the cam revolves it strikes the rod which in turn trips the hammer of the gun and causes it to fire. The cam is regulated so that it comes in contact with the rod just as each blade has passed the muzzle of the gun which can therefore fire at this time only. The engine revolves at least 1,000 turns per minute and as there are two chances for the gun to fire for each revolution, this would allow the gun to fire 2,000 shots per minute. The rate of fire of a machine gun varies from about 400 to 1,000 shots per minute according to the type of gun and the way in which it is rigged. The gun therefore has many more oppurtunities to fire between the blades of the propeller than its rate of fire will permit it to make use of. Consequently, the gun can work at full speed regardless of ordinary variations in the number of revolutions of the engine.

edit: bogged this from google

[bogged]

There is no mystery about a machine gun firing through a propeller without hitting the blades. Nearly everyone understands the principle by which the valves of a gasoline motor are timed so as to open and close at a given point in the revolution of the engine. In the same way a machine hgun may be timed to shoot. On the end of the cam shaft of the motor is plaved an additional cam. Next to this is a rod connected with the breech block of the gun. When the gun is not being fired the rod is held away from the cam by a spring. pressing the trigger brings the two in contact , and each time the cam revolves it strikes the rod which in turn trips the hammer of the gun and causes it to fire. The cam is regulated so that it comes in contact with the rod just as each blade has passed the muzzle of the gun which can therefore fire at this time only. The engine revolves at least 1,000 turns per minute and as there are two chances for the gun to fire for each revolution, this would allow the gun to fire 2,000 shots per minute. The rate of fire of a machine gun varies from about 400 to 1,000 shots per minute according to the type of gun and the way in which it is rigged. The gun therefore has many more oppurtunities to fire between the blades of the propeller than its rate of fire will permit it to make use of. Consequently, the gun can work at full speed regardless of ordinary variations in the number of revolutions of the engine.

edit: bogged this from google

yea sweet find mr.. tryin to find the water bit of the story mentioned above thats all.

[djr320kw]

Shadow

bang on That is exactly what I watched on Foxtel last week. It was invented before WW2 and was simple and relable.

[Shadow]

yea sweet find mr.. tryin to find the water bit of the story mentioned above thats all.

i realised you probably already found these bogges

i call BS on the water compression for machine gun thing!

[bogged]

i call BS on the water compression for machine gun thing!

By Joves I think hes right

[-Scott-]

i call BS on the water compression for machine gun thing!

By Joves I think hes right

Who said anything about water compressing? There are other liquids in this world...

[djr320kw]

I wont call BS on the water compression in the guns on the fighter plane they could have used another fluid. They could have used this but I know the most common method is as Shadow pointed out. Anyway the point is water does not compress as much as air.

[muzza_fattire]

Hey guys you are talking about different types of liquid. Water is different to brake fluid. That is why they dont use water in brake lines.

Not a very conclusive arguement there - kind of like saying Prado's are different to Landcruisers. Thats why they dont use Prado's offroad.

If water was used for brakes it would boil. Thats why they dont use it.

[djr320kw]

djr320kw wrote:
Hey guys you are talking about different types of liquid. Water is different to brake fluid. That is why they dont use water in brake lines.


Not a very conclusive arguement there - kind of like saying Prado's are different to Landcruisers. Thats why they dont use Prado's offroad.

If water was used for brakes it would boil. Thats why they dont use it

I wasnt making an argument I was simply suggesting that you can not compare these 2 liquids as they are different.

I was also under the impression that they also didnt use water (as you said it would boil) also because of compression but could be wrong

[Shadow]

djr320kw wrote:
Hey guys you are talking about different types of liquid. Water is different to brake fluid. That is why they dont use water in brake lines.


Not a very conclusive arguement there - kind of like saying Prado's are different to Landcruisers. Thats why they dont use Prado's offroad.

If water was used for brakes it would boil. Thats why they dont use it

I wasnt making an argument I was simply suggesting that you can not compare these 2 liquids as they are different.

I was also under the impression that they also didnt use water (as you said it would boil) also because of compression but could be wrong

Water would compress less than brake fluid, but the amount these fluids compress is significantly less than the amount your brake lines expand under pressure.

They dont use water in brakes for a crap load of reasons, the most obvious as muzza said is because it boils at 100 degrees C (at sea level). Brakes can easily exceed 170 degrees). It would also rust everything and offers no lubrication for the pistons.

[RoldIT]

djr320kw wrote:
Hey guys you are talking about different types of liquid. Water is different to brake fluid. That is why they dont use water in brake lines.


Not a very conclusive arguement there - kind of like saying Prado's are different to Landcruisers. Thats why they dont use Prado's offroad.

If water was used for brakes it would boil. Thats why they dont use it

I wasnt making an argument I was simply suggesting that you can not compare these 2 liquids as they are different.

I was also under the impression that they also didnt use water (as you said it would boil) also because of compression but could be wrong

Water would compress less than brake fluid, but the amount these fluids compress is significantly less than the amount your brake lines expand under pressure.

They dont use water in brakes for a crap load of reasons, the most obvious as muzza said is because it boils at 100 degrees C (at sea level). Brakes can easily exceed 170 degrees). It would also rust everything and offers no lubrication for the pistons.

As a side note to this, water can be used in brake lines in an emergency. (ie repair ruptured line, no brake fluid available.)

Obviously, this should be flushed and replaced with the correct fluid ASAP.

[Shadow]

i call BS on the water compression for machine gun thing!

By Joves I think hes right

Who said anything about water compressing? There are other liquids in this world...

ok

i was searching for water

researched for just compressable liquid and i found this

http://fluid.power.net/fpn/const/const003.html

George Contantinesco invented the system for the british air force (not then called the RAF) as a superior replacement to the mechanical driven systems.

ok i retract my BS call

[-Scott-]