In his efforts to promote his “opportunity for all” jobs plan, President Barack Obama visited a General Electric gas engine facility in Waukesha, Wisconsin on January 30, 2014. This engine plant produces engines that are designed specifically for use in gas and oil fields, which are some of the most demanding conditions that engines often operate under.
The significance of this visit by President Obama is that manufacturing is an important part of our nation’s economy. General Electric, which is a known innovator of all types of engines, employs over seven hundred individuals at their Waukesha engine plant. In fact, a machine operator named Reggie Troop had the distinct honor of introducing President Obama to his fellow employees, members of the media and others in attendance. Continue reading
As with any product or service, the cost of repairing a crankshaft will greatly depend on the region in which you reside. Are there many machine shops around? If so, this competition tends to drive down prices and the consumer realizes lower repair costs. However, if there are few automotive machine shops around, the cost to weld or grind a crankshaft will likely be higher. Setting local market conditions aside, which do influence labor costs, let’s look at some of the prices you can expect to pay when taking your crankshaft to an automotive machine shop for repair.
To understand how pricing crankshaft repairs are billed, it is important that you understand that most automotive machinists have a procedure that they follow to perform repairs. While grinding a crankshaft may have a flat fee, its current condition directly impacts the customer’s total out of pocket cost. For example, no automotive machinist wants to machine a dirty crankshaft in a $50,000.00 crankshaft grinding machine. Before internal engine parts are remanufactured, they must be cleaned, inspected and repaired in a sequence that matches the damage that must be repaired. Continue reading
Whenever machine work is performed on a crankshaft’s journals, these surfaces must be adequately finished before use in an engine. Besides maintaining a sufficient microfinish, it is also important that any burrs are removed. A critical area where burrs are often found are just inside of the journal’s oil passages. The way to remove these burrs is by using a process known as chamfering.
Burrs develop on oil passages from a variety of machining operations. Just grinding the crankshaft .010” can leave a small burr that would restrict the proper flow of oil while the engine is running. This poses a serious concern since engine bearings need to be adequately lubricated at all times. Chamfering is the industry standard in deburring crankshaft oil passages, which is explained in more detail below. Continue reading
When selecting a crankshaft for a high performance application, many vehicle owners question what type of steel they should use for their crankshaft. Obviously different steels have different qualities, but the strength of their composition largely depends on the heat treating process that was used after the crankshaft was produced. Although heat treating is beyond the scope of this page, we will look at the most common grades of steel used for forged and billet crankshafts below.
In an internal combustion engine, the crankshaft must rotate at high RPMs. As this rotation occurs, vibration can become more profound. Vibration will not only reduce horsepower in high performance engines, but it can cause internal engine components to prematurely fail. Because of this, engine balancing is necessary.
Balancing an engine requires simulating the weights of the pistons, piston pins, rings, connecting rods, engine bearings and even the oil with what is known as a bobweight (set pictured left). The bobweight accepts individual weights and is secured to connecting rod journals before the crankshaft is spun in a balancing machine. To calculate these weights, and create a bobweight, we must first look at the connecting rods and the components that appear on each end. The large end of the connecting rod, which is affixed to the crankshaft with bearings, is the rotating end. The small end of the connecting rod actually uses a reciprocating motion when the engine is operating. In calculating the weights for balancing, the rotating and reciprocating weights are used in the formula. Continue reading
Those who own performance engines, and want to gain the most horsepower possible, often seek the services of an automotive machine shop that provides a crankshaft knife edging service. Normally reserved for racing applications, a knife edged crankshaft can help the engine produce more horsepower. Below we will look at how the knife edging process is completed and the benefits it offers.
As you can tell by the picture to your left, a knife edged crankshaft refers to the shape of the crankshaft’s counterweights. Removing this material and bringing it to a sharp edge does a couple of things. First, knife edging can often remove pounds of weight from a V8 crankshaft. Even some V6 crankshafts will realize a significant weight reduction when the counterweights have been knife edged. Less weight equates to a rotating assembly that spins with less resistance, and this in itself is responsible for some gains in horsepower. Knife edging also reduces friction, which is explained below. Continue reading
A common service that most automotive machine shops offer is crankshaft polishing. This is a necessary step to prepare the crankshaft for the assembly of an engine. While there is some confusion about what can be expected from the polishing process, we will dispel the myths in this post and discuss why the polishing process is important.
First, many novice engine builders believe if their crankshaft is gouged that all it needs is to be polished. In most cases this line of thinking is wrong. Gouges, caused by material that may have been embedded in engine bearings, can damage a journal. Polishing can’t take these defects out of journals; at least with any degree of accuracy. If there are a lot of deep gouges, lines or other marks in a journal, chances are grinding the crankshaft first is the best course of action. Continue reading
To perform repairs on crankshafts, the crankshaft grinding wheel must be properly dressed. There are five points on the wheel that need to be dressed, which includes the face, the radii and the sides. Below we will take a look at how a crankshaft grinding wheel is dressed and how it impacts the quality of the finished product.
Since crankshaft grinding wheels are extremely hard and abrasive, a special tool is required to dress the wheel. This tool, which is commonly called the wheel dresser, utilizes an industrial diamond for cutting the wheel’s stone. Not surprisingly, there are various sizes of diamonds that are used and categorized according to their carat weight.
When it comes to automotive engines, there are four primary types of crankshafts used. The engine’s primary application determines which type of crankshaft is best suited to provide adequate performance and durability. Below we will take a look at the common types of crankshafts that are found in today’s engines and discuss the manufacturing processes used to create them.
Cast Iron Crankshafts
Cast iron crankshafts are most commonly found in ordinary passenger car engines and are favored by automobile manufacturers because they are inexpensive to produce. A cast iron crankshaft is made from molten iron or steel and simply poured into a mold. The raw casting is then rough machined so that it can be ground to its finish dimensions and then balanced. These types of crankshafts are relatively inexpensive and can be purchased new for $200 or even less. Since cast iron crankshafts contain flakes of graphite flakes, these crankshafts often have a grey visual appearance. Continue reading
Apart from a micrometer, one of the most important measuring instruments an automotive machinist uses when he or she grinds a crankshaft is an Arnold gauge. Unlike any other device, the Arnold gauge allows the operator of a crankshaft grinding machine to precisely read how much material is being taken off of the journal in real time. This ability, to see how much material is being ground off of a journal, allows the operator to grind crankshafts to extremely close tolerances.
The Arnold gauge, which is pictured left, is not only used in automotive machine shops. Many different industries, such as those involved with manufacturing aerospace and aviation components, rely on an Arnold gauge for a variety of O.D. grinding operations. With an accuracy of .0001”, it is quite easy to see why so many machinists are pleased with how well this gauge performs. Besides being accurate, an Arnold Gauge is also very easy for an operator to use. Continue reading