What is a piston ridge?

Updated: 4/28/2022
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11y ago

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Most people confuse ring ridge with piston ridge. The piston is wrapped in several rings which seal the combustion gases above the piston. These are made of a very hard material (usually cast steel). As the piston goes up and down they ride against the wall of the combustion chamber and wear it away. The part of the cylinder wall above where they reach that does not wear, resulting in a raised ridge. This MUST be removed when new rings are installed, as the old ring has also worn down, The new one will smash into the ridge and, being a hard brittle material, may break up, leaning jagged pieces of cast steel trapped between the piston and wall to tear grooves in both and ruin the engine.

The rings fit tightly into the piston grooves, but there is some slack. The edges of the groove must match the angle between the wear surface of the rings and the top/bottom, so the rings are supported across their full width and circumference. It looks like 90 degrees, but usually it is a little less, so the pressure of the moving piston forces the rings outward into the chamber wall, to improve the seal. Every time the piston reverses direction the rings hit the edges of the groove. Over time this pushes up ridges in the softer metal of the piston above and below the groove. These are piston ridges. They are cause no problem as the piston is a softer metal than either the rings or chamber wall. If they are high enough, they will show as bright bands above or below the ring grooves in the pistons. If they piston rides are more than a few thousandths wide, the grove may be over sized enough that the piston should be replaced, as the walls of the groove no longer support the ring properly. I have never seen piston ridges on a motor with under a hundred and fifty thousand miles, except for K-Cars and some of the little Chevy's from the seventies. The cause there was not mileage, but less than ideal metal in the pistons.

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Q: What is a piston ridge?
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What step must you perform before removing the piston from the bore to prevent damage?

Depending on the amount of wear in the cylinder, there may be a ridge at the top of it. If there is much of a ridge, the rings in the piston will catch on this and possible damage the piston. The ridge can be removed with a ridge reamer.

What tool is used to removed a piston?

the tool you are looking for is called a piston remover, sold at every local auto zone As the rings in the piston wear on the wall of the cylinder, a ridge forms at the top of the cylinder. This has to be removed with a Ridge Reamer. It cuts the ridge down until the cylinder is smooth otherwise the rings in the piston would catch on it and the piston cannot be removed. Once the cylinder is smooth, you can tap the piston out using the handle of a wooden handled hammer. To install the piston back in, you use a Ring Compressor that squeezes the rings into the grooves of the piston. Put lengths of plastic tubing over the Rod Bolts so that you don't nick the crankshaft and tap the piston into the cylinder with the same wooden hammer handle.

Should the cylinder ridge be removed before the piston?

No, you dont need to remove the cylinder ridge before. I never have and i replace them all the time.

Is it hard to replace piston?

It is just about the hardest most difficult part of an engine to replace. The engine has to come out. The head has to be taken off. The rod of the piston has to be disconnected from the crankshaft. the top of the cylinder has to have a ridge reamer operated on it to get the piston out.

What is cylinder ridge?

In a internal combustion engine, a cylinder ridge is an unworn area around the top of the cylinder wall. In that engine, the piston moves up and down in the cylinder, and the rings seal the piston in that cylinder. But the rings are spaced "down a bit" from the top of the piston. And when the piston reaches top dead center in the cylinder, the rings haven't gone all they way to the top of the cylinder. They end up wearing the cylinder out "underneath" that top area. In other words, it's the top part of the cylinder that is not in contact with the piston rings. It's the "unworn" part, if you will.

What are the Difination and terms of car piston and piston parts?

One of the parts in the piston are the piston head,

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What are bent engine pistons?

A bent engine piston is a reference to the piston rod. The piston cannot be bent, but the piston rod can be bent.

What is piston effort?

The driving force action on the piston is called piston effort.In other words the net resultant of all the other forces acting on the piston is called piston effort.

Why there is rings in piston?

The piston rings create a seal between the piston and the cylinder wall.

What are the Parts of the piston?

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Is ridge a verb?

Yes, the word ridge is both a noun (ridge, ridges) and a verb (ridge, ridges, ridging, ridged).