There is still a vibrant hot rod culture worldwide, especially in Canada, the United States, the United Kingdom, Australia and Sweden. The hot rod community has now been subdivided into two main groups: street rodders and hot rodders.
The term “hot rod” has had various uses in relation to performance cars. For example, the Ontario Ministry of the Environment in its vehicle emissions regulations refers to a hot rod as any motorized vehicle that has a replacement engine differing from the factory original.Deuce coupe featuring ’32 grille shell, original headlights, chrome dropped I-beam axle and tube shocks. Note stock frame rails, disc brakes, Lakester pipes
What is rod crank ratio?
Rod ratio is the mathematical relationship between the overall length of the connecting rods and the stroke of the crankshaft. Divide rod length by the crank stroke and you get the rod ratio.
Particularly during the early 1960s, a genre of “hot rod music” rose to mainstream popularity. Hot rod music was largely a product of a number of surf music groups running out of ideas for new surfing songs and simultaneously shifting their lyrical focus toward hot rods. Hot rod music would prove to be the second phase in a progression known as the California Sound, which would mature into more complex topics as the decade passed. Hot rods were used as the theme of Lightning Rod, a Rocky Mountain Construction roller coaster at Dollywood.In the ’50s and ’60s, the Ford flathead V8 was supplanted by the Chrysler FirePower engine (known as the “early hemi”). Many hot rods would upgrade the brakes from mechanical to hydraulic (“juice”) and headlights from bulb to sealed-beam. A typical mid-1950s to early 1960s custom Deuce was fenderless and steeply chopped, powered by a Ford or Mercury flathead, with an Edelbrock intake manifold, Harman and Collins magneto, and Halibrand quick-change differential. Front suspension hairpins were adapted from sprint cars, such as the Kurtis Krafts.
What connects crank to connecting rod?
Crank pin: The crank pin is a cylindrical component attached to the crankshaft and extends into the big end of the connecting rod. The crank pin allows the connecting rod to pivot and rotate relative to the crankshaft as the piston moves up and down in the cylinder.
“Rat rod” ’29 Model A coupe with a ’32 grille shell, upgraded brakes, “bobbed” frame rails, channeled, powered by an early flatty equipped with Edelbrock aftermarket head and aftermarket chrome carb hats.By the 1970s, the 350 cu in (5.7 L) small-block Chevy V8 was the most common choice of engine for hot rods. Another popular engine choice is the Ford Windsor engine. During the 1980s, many car manufacturers were reducing the displacements of their engines, thus making it harder for hot rod builders to obtain large displacement engines. Instead, engine builders had to modify the smaller engines (such as using non-standard crankshafts and pistons) to obtain larger displacement. While current production V8s tended to be the most frequent candidates, this also applied to others. In the mid-1980s, as stock engine sizes diminished, rodders discovered the 215 cu in (3.5 L) aluminum-block Buick or Oldsmobile V8 could be modified for substantially greater displacement, with mainly wrecking yard parts. This trend was not limited to American cars; Volkswagen enthusiasts similarly stretched stock 1600cc engines to over two liters.The origin of the term “hot rod” is unclear. For example, some say that the term “hot” refers to the vehicle’s being stolen. Other origin stories include replacing the engine’s camshaft or “rod” with a higher performance version. According to the Hot Rod Industry Alliance (HRIA) the term changes in meaning over the years, but “hot rodding has less to do with the vehicle and more to do with an attitude and lifestyle.” For example, hot rods were favorites for greasers.After World War II, many small military airports throughout the country were either abandoned or rarely used, allowing hot rodders across the country to race on marked courses. Originally, drag racing had tracks as long as 1 mi (1.6 km) or more, and included up to four lanes of racing simultaneously. As some hot rodders also raced on the street, a need arose for an organization to promote safety, and to provide venues for safe racing. The National Hot Rod Association was founded in 1951, to take drag racing off the streets and into controlled environments.
Is a hot rod a muscle car?
By the 1950s, hot rods had evolved into something even more exciting: muscle cars. These beasts had been designed from the ground up to be fast, powerful, and stylish, with engines so big they could barely fit under the hood.
However, the 1973 Oil Crisis caused car manufacturers to focus on fuel efficiency over performance, which led to a resurgence of interest in hot rodding. As the focus shifted away from racing, the modified cars became known as “street rods”. The National Street Rod Association (NSRA) was formed and began hosting events.
Typical modifications were removal of convertible tops, hoods, bumpers, windshields, and/or fenders; channeling the body; and modifying the engine by tuning and/or replacing with a more powerful type. Wheels and tires were changed for improved traction and handling. Hot rods built before 1945 commonly used ’35 Ford wire-spoke wheels.Hot rods first appeared in the late 1930s in southern California, where people raced modified cars on dry lake beds northeast of Los Angeles, under the rules of the Southern California Timing Association (SCTA), among other groups. This gained popularity after World War II, particularly in California, because many returning soldiers had received technical training. The first hot rods were old cars (most often Fords, typically 1910s-1920s Model Ts, 1928–31 Model As, or 1932-34 Model Bs), modified to reduce weight. Engine swaps often involved fitting the Ford flathead V8 engine (known as the “flatty”) into a different car, for example, the common practice in the 1940s of installing the “60 horse” version into a Jeep chassis.As automobiles offered by the major automakers began increasing performance, the lure of hot rods began to wane. With the advent of the muscle car, it was now possible to purchase a high-performance car straight from the showroom.Hi-boy Deuce roadster with flatty (with factory head and exhaust but aftermarket alternator ignition and dual-carb intake), dropped tube axle, and drum brakes.
What is a hot rod car?
Hot rods are typically American cars that might be old, classic, or modern and that have been rebuilt or modified with large engines optimized for speed and acceleration.
Author Tom Wolfe was one of the first to recognize the importance of hot rodding in popular culture and brought it to mainstream attention in his book The Kandy-Kolored Tangerine-Flake Streamline Baby.
Hot rods are typically American cars that might be old, classic, or modern and that have been rebuilt or modified with large engines optimized for speed and acceleration. One definition is: “a car that’s been stripped down, souped up and made to go much faster.” However, there is no definition of the term that is universally accepted and the term is attached to a wide range of vehicles. Most often they are individually designed and constructed using components from many makes of old or new cars, and are most prevalent in the United States and Canada. Many are intended for exhibition rather than for racing or everyday driving.
There are magazines that feature traditional hot rods, including Hot Rod, Car Craft, Rod and Custom, and Popular Hot Rodding. There are also television shows such as My Classic Car, Horsepower TV, American Hot Rod, Fast and Loud, and Chop Cut Rebuild.Locals in these countries, influenced by American culture, have created a local hot rod culture which is vibrant in Sweden and Finland where enthusiasts gather at meetings such as Power Big Meet and clubs like Wheels and Wings in Varberg, Sweden have established themselves in Hot Rod culture. Since there is very little “vintage tin” the hot rods in Sweden are generally made with a home made chassis (usually a Model T or A replica), with a Jaguar (or Volvo 240) rear axle, a small-block V8, and fiberglass tub, but some have been built using for instance a Volvo Duett chassis. Because the Swedish regulations required a crash test even for custom-built passenger cars between 1969 and 1982, the Duett option was preferred, since it was considered a rebodied Duett rather than a new vehicle. Some 1950s and 1960s cars are also hot rodded, like Morris Minor, Ford Anglia, Volvo Amazon, Ford Cortina, ’57 Chevy, to name but a few. These are known as custom cars (sometimes spelled Kustom).
There are various theories about the origin of the term “hot rod”. The common theme is that “hot” related to “hotting up” a car, which means modifying it for greater performance. One theory is that “rod” means roadster, a lightweight 2-door car which was often used as the basis for early hot rods. Another theory is that “rod” refers to camshaft, a part of the engine which was often upgraded in order to increase power output.
There is a contemporary movement of traditional hot rod builders, car clubs and artists who have returned to the roots of hot rodding as a lifestyle. This includes a new breed of traditional hot rod builders, artists, and styles, as well as classic style car clubs. Events like GreaseOrama feature traditional hot rods and the greaser lifestyle. Magazines like Ol’ Skool Rodz, Gears and Gals, and Rat-Rods and Rust Queens cover events and people.Some terms have an additional, different meaning among customizers than among rodders: NOS, for instance, is a reference to new old stock, rather than nitrous oxide.
The sideways force exerted on the piston through the connecting rod by the crankshaft can cause the cylinders to wear into an oval shape. This significantly reduces engine performance, since the circular piston rings are unable to properly seal against the oval-shaped cylinder walls.
Fork-and-blade rods, also known as “split big-end rods”, have been used on V-twin motorcycle engines and V12 aircraft engines. For each pair of cylinders, a “fork” rod is split in two at the big end and the “blade” rod from the opposing cylinder is thinned to fit into this gap in the fork. This arrangement removes the rocking couple that is caused when cylinder pairs are offset along the crankshaft.
The predecessor to the connecting rod is a mechanic linkage used by water mills to convert rotating motion of the water wheel into reciprocating motion.
Radial engines typically use master-and-slave connecting rods, whereby one piston (the uppermost piston in the animation), has a master rod with a direct attachment to the crankshaft. The remaining pistons pin their connecting rods’ attachments to rings around the edge of the master rod.
Notable engines to use fork-and-blade rods include the Rolls-Royce Merlin V12 aircraft engine, EMD two-stroke Diesel engines, and various Harley Davidson V-twin motorcycle engines.Multi-bank engines with many cylinders, such as V12 engines, have little space available for many connecting rod journals on a limited length of crankshaft. The simplest solution, as used in most road car engines, is for each pair of cylinders to share a crank journal, but this reduces the size of the rod bearings and means that matching (i.e. opposite) cylinders in the different banks are slightly offset along the crankshaft axis (which creates a rocking couple). Another solution is to use master-and-slave connecting rods, where the master rod also includes one or more ring pins which are connected to the big ends of slave rods on other cylinders. A drawback of master-slave rods is that the stroke lengths of all slave pistons not located 180° from the master piston will always be slightly longer than that of the master piston, which increases vibration in V engines.
In a steam locomotive, the cranks are usually mounted directly on the driving wheels. The connecting rod is used between the crank pin on the wheel and the crosshead (where it connects to the piston rod). The equivalent connecting rods on diesel locomotives are called ‘side rods’ or ‘coupling rods’. On smaller steam locomotives, the connecting rods are usually of rectangular cross-section, however marine-type rods of circular cross-section have occasionally been used.
During each rotation of the crankshaft, a connecting rod is often subject to large and repetitive forces: shear forces due to the angle between the piston and the crankpin, compression forces as the piston moves downwards, and tensile forces as the piston moves upwards. These forces are proportional to the engine speed (RPM) squared.The 1712 Newcomen atmospheric engine (the first steam engine) used chain drive instead of a connecting rod, since the piston only produced force in one direction. However, most steam engines after this are double-acting, therefore the force is produced in both directions, leading to the use of a connecting rod. The typical arrangement uses a large sliding bearing block called a crosshead with the hinge between the piston and connecting rod placed outside the cylinder, requiring a seal around the piston rod.
One of the most complicated examples of master-and-slave connecting rods is the 24-cylinder Junkers Jumo 222 experimental airplane engine developed for World War II. This engine consisted of six banks of cylinders, each with four cylinders per bank. Each “layer” of six cylinders used one master connecting rod, with the other five cylinders using slave rods. Approximately 300 test engines were built, however the engine did not reach production.
A connecting rod for an internal combustion engine consists of the ‘big end’, ‘rod’ and ‘small end’. The small end attaches to the gudgeon pin (also called ‘piston pin’ or ‘wrist pin’), which allows for rotation between the connecting rod and the piston. Typically, the big end connects to the crankpin using a plain bearing to reduce friction; however some smaller engines may instead use a rolling-element bearing, in order to avoid the need for a pumped lubrication system. Connecting rods with rolling element bearings are typically a one piece design where the crankshaft must be pressed together through them, rather than a two piece design that can be bolted around the journal of a one piece crankshaft.Other materials include T6-2024 aluminium alloy or T651-7075 aluminium alloy, which are used for lightness and the ability to absorb high impact at the expense of durability. Titanium is a more expensive option which reduces the weight. Cast iron can be used for cheaper, lower performance applications such as motor scooters. Typically there is a pinhole bored through the bearing on the big end of the connecting rod so that lubricating oil squirts out onto the thrust side of the cylinder wall to lubricate the travel of the pistons and piston rings. A common arrangement for the big-end bearing is for the fork rod to have a single wide bearing sleeve that spans the whole width of the rod, including the central gap. The blade rod then runs, not directly on the crankpin, but on the outside of this sleeve. This causes the two rods to oscillate back and forth (instead of rotating relative to each other), which reduces the forces on the bearing and the surface speed. However the bearing movement also becomes reciprocating rather than continuously rotating, which is a more difficult problem for lubrication.
A connecting rod, also called a ‘con rod’, is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft. The connecting rod is required to transmit the compressive and tensile forces from the piston. In its most common form, in an internal combustion engine, it allows pivoting on the piston end and rotation on the shaft end.
The predecessor to the connecting length is the mechanical linkage used by Roman-era watermills. An early example of this linkage has been found at the late 3rd century Hierapolis sawmill in Roman Asia (modern Turkey) and the 6th century saw mills at Ephesus in Asia Minor (modern Turkey) and at Gerasa in Roman Syria. The crank and connecting rod mechanism of these machines converted the rotary motion of the waterwheel into the linear movement of the saw blades.
The materials used for connecting rods widely vary, including carbon steel, iron base sintered metal, micro-alloyed steel, spheroidized graphite cast iron. In mass-produced automotive engines, the connecting rods are most usually made of steel. In high performance applications, “billet” connecting rods can be used, which are machined out of a solid billet of metal, rather than being cast or forged.
An early documentation of the design occurred sometime between 1174 and 1206 AD in the Artuqid State (modern Turkey), when inventor Al-Jazari described a machine which incorporated the connecting rod with a crankshaft to pump water as part of a water-raising machine, though the device was more complex than typical crank and connecting rod designs. There is also documentation of cranks with connecting rods in the sketch books of Taccola from Renaissance Italy and 15th century painter Pisanello.
The amount of sideways force is proportional to the angle of the connecting rod, therefore longer connecting rods will reduce the amount of sideways force and engine wear. However, the maximum length of a connecting rod is constrained by the engine block size; the stroke length plus the connecting rod length must not result in the piston travelling past the top of the engine block.Failure of a connecting rod, often called “throwing a rod” often forces the broken rod through the side of the crankcase and thereby rendering the engine irreparable. Common causes of connecting rod failure are tensile failure from high engine speeds, the impact force when the piston hits a valve (due to a valvetrain problem), rod bearing failure (usually due to a lubrication problem), or incorrect installation of the connecting rod.
A connecting rod can rotate at both ends, so that the angle between the connecting rod and the piston can change as the rod moves up and down and rotates around the crankshaft.
rod, old English measure of distance equal to 16.5 feet (5.029 metres), with variations from 9 to 28 feet (2.743 to 8.534 metres) also being used. It was also called a perch or pole. The word rod derives from Old English rodd and is akin to Old Norse rudda (“club”). Etymologically rod is also akin to the Dutch rood which referred to a land area of 40 square rods, equal to one-quarter acre, or 10,890 square feet (1,012 square metres). It also denoted just one square rod, or 272.25 square feet (25.29 square metres). The rood also was a British linear unit, containing 660 feet (201.2 metres).We’ve detected some suspicious activity coming from your IP address and have temporarily blocked it as a security precaution. Please check the box to let us know you’re human (sorry, no robots allowed).PartsGiant.com is the powersports specialist. If you have questions or problems, just email us and our expert customer support staff will do everything possible to help. Awesome kit. Extremely professional parts. I have installed a few and never had a problem with any quality or workmanship. I highly recommend this kit. Hot Rods is the best. Yes, if you were to select the 2014 Yamaha YZ250F 4-Stroke crankshaft rebuild kit from our fit guide, you’d receive the correct components for that machine.Yes, there is a complete crankshaft kit offered for that 1988 TRX250R. You should be able to select that year/make/model from the vehicle selection drop down before adding to your cart.Everything I needed in a lower end engine rebuild kit at a competitive price plus boxes were sturdy and packaged with protection around all parts especially the crankshaft and stickers are always a welcomed addition.Parts came in within a couple days, super impressed. Crank and gaskets/orings were packaged securely. Installed with zero issues. Will be purchasing again for future bikes. If you are an international customer and would like to change the currency that prices are displayed in, you can do so here. Please note that Checkout Prices will be in US Dollars. As with rod ratios, the geometric relationship between bore and stroke can also affect an engine’s power and RPM potential. Even so, such generalities often don’t hold true across the spectrum of production engines or engines that are purpose-built for racing.
What are the 4 parts of the crankshaft?
A crankshaft comprises the following components:Main journals.Crank pins.Crank webs.Counterweights.
A 500 cubic inch Pro Stock drag motor may be running a bore size of 4.750 inches with a crank stroke of 3.52 inches. At 10,000 RPM, the piston speed in one of these motors is about the same as a NASCAR engine. If they are running a smaller bore with a longer crank (say 3.75 inches), pistons speeds may be as high as 6,250 feet per minute. The maximum achievable rod ratio is always going to be limited by the physical dimensions of the block (deck height, tall or short), the longest rods that are available to fit the engine (off-the-shelf mass produced rods or custom made), and the shortest pistons that will work with the rod, block and stroke combination. The combined weight of the rod and piston has more effect on momentum and throttle response than the rod ratio. Also, moving the wrist pin higher up in the piston and using a shorter piston may create some piston wobble and instability issues if you go too far. Because of this, excessive rod ratio may actually be detrimental to engine performance. If you build the same 350 engine with longer 6-inch rods, the rod ratio becomes 1.72. And if you are building a 383 stroker with 6-inch rods, the rod ratio becomes 1.6 due to the longer stroke (3.750 inches).D&J Precision Machine has specialized in Cummins diesel engine performance since its beginning in 2009. When Covid hit we saw a huge drop in sales. Luckily, it only ended up lasting a couple months, but it had us scrambling to figure out what to do to keep all our guys employed, and the banks off our backs.The advancements within the performance diesel world over the past 20 years have been nothing short of phenomenal. In fact, within just the last five to 10 years, that progress has been even more rapid and impressive, but few progressions have been more astonishing than those within the Pro Mod Diesel realm.
What do these numbers mean? They express a geometric relationship between the rods, crankshaft and pistons. The lower the rod ratio, the greater the side forces exerted by the pistons against the cylinder walls. This increases wear on the piston skirts and cylinder walls, and creates a higher level of vibration inside the engine. The increase in friction can also elevate coolant and oil temperatures.6,600 RPM (due to hydraulic lifters). Both are excellent engines with lots of performance potential, but the Ford revs higher because of its overhead cam heads, and makes more horsepower (526 vs 460).
A closely related topic to rod ratio is that of bore and stroke. If the bore and stroke dimensions in an engine are the same (say a 4.00 inch bore with a 4.00 inch stroke), the engine is said to be “square.” If the bores are larger than the stroke, the engine is “oversquare,” and if the stroke is longer than the bore diameter it is said to be “undersquare.”
As a general rule, large bore, short stroke engines are high revving, high power engines good for road racing and circle track applications. Pro Stock racers also like this combination for drag racing as do NASCAR engine builders. Small bore, large stroke engines, on the other hand, are better for low RPM torque, street performance, towing and pulling, but have limited RPM potential.
Some engine builders say a “good” rod ratio is anything 1.55 or higher. Production engines may have rod ratios that range from 1.4 to over 2.0, with many falling in the 1.6 to 1.8 range. Four cylinders tend to have lower rod ratios (1.5 to 1.7 range) while many V6s have somewhat higher rod ratios of 1.7 to 1.8. As for V8s, they typically range from 1.7 to 1.9. Often, the rod ratio is dictated by the design and deck height of the block, and the pistons, rods and crank that are available to fit the block.
To help maintain high performance and a longer life expectancy for your engine, motor oil is essential. Not only does it help to lubricate your vehicle’s engine, it also offers many additional benefits, including reducing friction and wear on moving parts, cooling the engine down, and keeping it clean. Related Articles – Import Engines: A Look
They’re the pinnacle of drag racing, and the engine builders, crew chiefs and teams who make these cars function at peak performance all season long are looking at every single area of the engine and the car to make it down the track as fast as possible.What about longer rod ratios? Using longer connecting rods with the same stroke reduces the side loading on the pistons, which reduces friction. It also increases the piston dwell time at Top Dead Center. Holding compression for maybe half a degree of crankshaft rotation longer at TDC improves combustion efficiency and squeezes a little more power out of the air / fuel mixture. Typically, an engine with a higher rod ratio will produce a little more power from mid-range to peak RPM.
On the other hand, lower rod ratios do have some advantages. Shorter rods mean the overall height of the block can be shorter, which means the overall weight of the block can be lighter. The engine will typically pull more vacuum at low RPM, which means better throttle response and low end torque (good for street performance and everyday driving). Spark timing can be advanced a few degrees for some additional low speed torque, and the engine is less prone to detonation, which can be a plus in turbocharged, supercharged or nitrous applications.
Some people put way too much emphasis on rod ratios and worry excessively about how their engine’s rod ratio will affect performance. Our take on the issue is that rod ratio is just a number that may or may not make much difference depending on the situation. In some cases, it can make a slight difference and in others it seems to make no significant difference whatsoever. Peak horsepower and torque depend on too many other variables. High piston speeds not only increase friction and ring wear inside the engine, it also increases loads on the connecting rods dramatically. Using longer rods with shorter, lighter pistons can help reduce the stress on the rods in these applications. Many of the big names in motorsports have built and used the 2JZ in their own racing machines, proving that the engine platform can be competitive in various formats.As far as materials for forged pistons are concerned, there are three of note. Probably the most widely used, because it is also used for OE applications, is the Federal Mogul (TRW/Sealed Power division) VMS75 alloy. This was developed probably as far back as the 1960s as a good all-around high-performance alloy for pistons. Most of the rest of the piston industry uses one or both of two alloys, these being 2618 and 4032. The 2618 is most commonly used for outright race pistons as toughness at elevated temperatures (up to about 575 F) is good. On the down side, it lacks the hardness of 4032, which is a high-silicon alloy. Though slightly less tough, the 4032 alloy is a better material for high performance street and race use and would, in most cases, be the alloy of choice for such. At the end of the day, consulting your piston manufacturers about the choice is the way to go, as they are the experts here.
Crank Know-HowCranks are essentially available in three grades: cast, forged, and billet. That is also about the order of their cost. Many production vehicles have cast-iron cranks. These won’t take either the outright power or abuse a forged one will, but they are plenty strong enough for even a decent factory street performer. Also, cast iron has very good wear properties so the life of a cast crank can be very good. A forged crank is a step up the ladder and, for more money, provides greater strength.
Oil ring widths are also coming around with down sizing. For most V-8s, a 3/16-inch (0.187-inch) wide ring has been the most commonly used size. But efforts to effectively reduce size and weight have brought the 1/8-inch (0.125-inch) and 3mm (0.118-inch) rings into vogue.A regular cast piston can have up to about 10 percent to 11 percent silicon in it. This is about the eutectic point. Any more silicone will put the alloy into the hypereutectic range and as a result, form free crystals of silicon. Normally, these free silicon crystals will cause a reduction in strength, but with suitable heat treatment a hypereutectic alloy can be toughened up to a level above that of a regular cast piston.
Although the term “hypereutectic” is commonly used, it is often not understood. For “hyper – eutectic,” read “super – saturated.” An alloy that is at the point where no more of the principle alloying element will dissolve in the parent metal is said to be at the eutectic or saturated point.
Let’s now consider a few key dimensional aspects of the piston design. Probably the most important is the piston’s compression height (see the sidebar for definition) as this controls the rod length that can be used with any given block height and stroke length. For most normal situations, a compression height of 1 inch is about the lower limit, but it can, by using thinner, and usually more expensive rings, be made less. Also, a reduction in pin diameter (which should not be contemplated unless you know it will be a functional combination for your particular application) can allow another incremental reduction in compression height. Once we know the compression height that can be used, we can, using half the stroke length (the crank’s throw) and the block’s deck height, work out the longest rod that can be accommodated within the block. By adding the compression height to the crank’s throw dimension and subtracting this from the block height, we end up with the longest rod that will fit. For example, the Ford 5.0 engine stretched to 347 cubes looks like this: crank throw (1.700 inches) + piston compression height (1.000 inches) = 2.7 inches. 2.700 inches subtracted from the block height (8.200 inches) = 5.5 inches. As it happens, a 5.5-inch rod for this application is not an off-the-shelf deal, but companies such as Crower can easily custom produce such. In this instance, a 5.4-inch rod is commonly available, so if the budget does not allow a custom rod, this is what we would go with and use a piston with a hundred thousandths (0.100) more compression height.
1. The heat treat on the 4340 alloy gives it a very hard surface with a tough core. The super-hard surface, in conjunction with a micro-polish finish, ensures very low wear rates on all bearing surfaces. 2. Mass in and around the center of the crank is of no aid toward balancing the reciprocating components. To keep the crank light, the counterbalance mass needs to be concentrated as far from the crank centerline as possible, hence the undercut crank webs to form a pendulum counterweight. 3. The form of the web connecting the rod journal to the main journal is critical for a maximum performance crank. Too thin and the crank breaks, too thick and the counterweight necessary to balance it goes up. Everything in and around the rod journal needs to be light. 4. This is an extension of the last point, as a hollow journal means less mass is necessary on the counterweight to balance it out. Also, contrary to what you may expect, a hollow journal, if correctly done, is actually stronger than a solid one. A key ingredient here is the radius between the hole and the web of the crank. 5. From the front end of this crank it can be seen just how much the counter weights are cut away to reduce overall mass. 6. The star-form flywheel flange is mostly to reduce the crank’s overall weight, although it does contribute a small degree toward moment of inertia reduction. 7. The aero leading edges of this crank cut aero drag and viscous losses. This is a big deal for crankcases that run at near atmospheric pressures. For a highly scavenged, low-pressure crankcase, such as in an all-out engine, the gains from aero mods are significantly less because the density of the air within the crankcase is less than half of normal. 8. The fillet radius on a crank has far more to do with its fatigue life than does the journal diameter. This being the case, attention to the fillet radius is important. Not only should it be as large as possible but also very finely polished to avoid stress risers.In terms of outright strength and toughness, a hypereutectic piston still falls short of a forged piston, but not by as much as the difference in material strength might suggest. The reason for this is that the process of casting a piston, as opposed to forging it, allows the material to be put right where it is needed to support the stresses involved. With a forged piston, the underside has to be designed such that the forging punch can be extracted after the piston blank is formed. It is only by extensive (and costly) post forging machining that a forged piston can rival a cast piston in terms of lightness. By using up some of this low weight advantage by incorporating extra material at strategic points, the cast hypereutectic piston, in practice, comes out looking a lot stouter.
What does hot rod mean in slang?
US. Slang. 1. an automobile, usually an old one stripped of extraneous parts, adjusted or rebuilt for quick acceleration and great speed.
If the stroke is increased by 10 percent, the reciprocating loads will, at any given rpm, go up by 10 percent. Although reciprocating loads are proportional to the mass involved, they go up with the square of the rpm. What this means is that if the engine is turned at 10 percent higher rpm, the reciprocating forces go up by 21 percent (1.1x 1.1 = 1.21). To offset the inevitable combination of the greater stroke and the desire for more rpm, we need to look for a lighter-than-stock piston. Checking through various manufactures’ catalogs looking for pistons that are toward the lighter side is time well spent. Here, ROSS, Mahle, JE and KB are worthwhile starting points. If the piston is offered with a lightweight pin upgrade, then, budget allowing, this is well worth considering.The last important deal to look at is the selection of the rings. Increase the side loads and the inevitable greater block flexure means that sealing the cylinder will get a little more difficult. Not only will the use of thinner compression rings help reduce the compression height but it will also better seal the cylinder. For rings, 1/16 inch (0.062 inch) and 1.5mm (0.059 inch) are common these days and are thinner than were normally used just a few years ago. But even thinner rings are becoming more popular. Both 3/64-inch (0.046-inch) and 1mm (0.039-inch) rings are an everyday deal for many up-market hi-po vehicles being built today. If you want to see what is available, check out Total Seal’s Web site.
WHY YOUR ENGINE NEEDS A GOOD CRANK DAMPERForget what you have heard or read about lightweight crank hubs. They may have a lower moment of inertia, but do not deliver more power than a heavier crank damper. In the real world, it’s not as simple as the dynamics of a crankshaft. At some point in the mid- to upper-rpm range, the damper will go into a bending and torsional vibrational resonance. In so doing, it will behave something like this.
ReliabilitySo how good are these cast steel cranks? Assuming a reputable company like SCAT, who also supplies an OEM market that calls for tight quality control, we find they are extremely good for all usage up to moderate race levels. Personal experience over a 15-year period with small-block engines up to 580 hp has shown none have failed or worn out. A road-race engine built in 1999 now has over 5,000 race miles on it at a power level of some 500 hp, and the last teardown revealed that it, and the bearings, was still in near-perfect condition. Although potential reliability is built into a good stroker crank, it should not be taken for granted. Any time the stroke is increased, there is an increase in inertial loads. These and other associated factors need to be taken care of in an appropriate manner. Let’s look at reciprocating loads first.To accommodate the longest rod possible, piston manufactures are pushing the pin bore up to the point it cuts across the oil ring grove. To allow this to be successfully run, a steel ring support rail is located on the bottom face of the oil ring groove after the piston has been assembled onto the rod. This bridges the break in the bottom of the groove and also allows the oil ring to function as intended.
Although factory cranks are usually lesser grade steels, the steels most commonly used in aftermarket cranks are 4130 and 4340. Depending on the cost of the crank, these can be had with surface hardening which gives a very good wear life. Last on the list are billet cranks. These are made from a block of steel because there is no appropriate forging available from which to machine the desired design of crank. Needless to say, they can be very expensive.
If an engine is stripped for a re-build, it is a cost-effective plan to consider all your crank options. These days the availability of quality cast steel cranks makes installing the original used crank only barley less money. Cast steel, which can be looked upon as a hybrid between forged steel and cast iron, allows far tougher cranks to be produced at near the cost of regular cast iron ones. Although it still falls short of a forged crank’s ultimate strength, it is an extremely cost-effective halfway house between a regular OEM cast and an aftermarket forged crank. Also, cast steel opens the door to reliable low-cost stroker cranks. Because they can be so inexpensive, you can figure that a new quality stroker crank can be as little as about $75-$125 more than getting your existing, and almost certainly fatigued, crank re-ground.The mechanical contrivance most responsible for converting the rising pressure from the combustion of air and fuel is the crankshaft, along with the rods and pistons contained within the block. What you choose to use here can make the difference between building an indifferent and potentially unreliable engine and building a real powerhouse. With that in mind, let’s start the ball rolling at the centerline of the crank and work our way out from there.
Piston SelectionWhen buying pistons you will be presented with some material options that you need to know about. Firstly, regular cast pistons are the cheapest option. To make them harder, the aluminum used for regular replacement and earlier-style OEM cast pistons is alloyed with silicon (which is in essence melted sand). The silicon content makes the piston harder and more wear-resistant, but set against this is the increased brittleness. This makes it the least desirable of the type of pistons available to us for performance use. Next on the list is a hypereutectic piston. These started gaining popularity for lower-cost performance applications in Europe back in the mid ’70s. In the early ’80s, Sealed Power started experimenting with hypereutectic pistons and subsequently introduced a successful line of them. This was followed by Silovolite, who introduced the Keith Black (KB) signature series performance-oriented hypereutectic piston.
The SCAT Q-Light super crank shown here is the kind used in a maximum-effort engine such as an 840hp Nextel Cup unit. Such a crank seeks to satisfy three distinct criteria. Firstly, it must be strong and highly fatigue-resistant to endure the ultra high loads over extended periods. Secondly, it must have the minimum overall mass and the lowest moment of inertia possible to enhance vehicle acceleration. Thirdly, its windage should be as low as possible to cut internal aero drag and viscous losses. We will take a tour of this crank and detail its design philosophy.Returns and refunds from participating RM Cash items will take funds out of your account. If you’ve used the cash already from items that you’re returning, we’ll just deduct it from the amount we’re crediting back to you. The following brands have requested to be removed from the RM Cash program: AMS®, JOE ROCKET®, MOOSE RACING®, REKLUSE®, SCOTTS PERFORMANCE®, SIDI®, THOR®, ICON®, DRAG SPECIALTIES®, HIGHLINE RECREATION®, RAM MOUNTS®, ARCTIVA®, TRUKKE®, KLIM®, SCORPION®, Z1R®, RAPID TRANSIT®, VEMAR®, POWER-TRIP®, ROCKWELL®, AGV®, DOUBLE TAKE®, AMERICAN KARGO®, SCHUBERTH®, MOTOZ®, FORCEFIELD®, FREEDOM PERFORMANCE®, BRP®, FALCO®, S&B FILTERS®, ICON 1000®, DP BRAKES®, CLEAN SPEED®, ZAC SPEED®, OX-BRAKE®, LECTRON®, STEGZ®, PYTHON®, AXP RACING®, SHOWROOM®. Withstanding forces: Connecting rods are designed to withstand the high stresses and forces applied during operation. This allows them to transmit and convert motion effectively without breaking or failing under the forces applied to them.
What is a rod bearing?
What are connecting rod bearings? Connecting rod bearings in modern engines are plain bearings that support the conrod on the bearing journal of the crankshaft. The large eye of the connecting rod is sp
lit and is closed by the connecting rod bearing cap at the base of the connecting rod with expansion screws.
Bolts and nuts: Connecting rods are often held together with bolts and nuts, which allow them to be easily disassembled and reassembled for maintenance or repair. These bolts and nuts may be made from various materials, such as steel or an alloy.
A connecting rod is a component of a piston engine that connects the piston to the crankshaft. It is typically made of steel or aluminum and has a specific length and shape that allows it to transfer the motion of the piston to the crankshaft. In a four-stroke engine, the connecting rod is responsible for converting the reciprocating motion of the piston into the rotational motion of the crankshaft.I-beam connecting rods: I-beam connecting rods are similar to H-beam connecting rods but have an I-shaped cross-section instead of an H-shaped cross-section. This provides a slightly different balance of strength and weight, and I-beam connecting rods are often used in high-performance engines that require a lightweight and strong connecting rod.A connecting rod diagram is a visual representation of a connecting rod, which is a critical component in an engine. The diagram typically shows the connecting rod in relation to other parts of the engine, such as the piston, crankshaft, and cylinder. It may also include labels and other annotations to help explain the function and operation of the connecting rod. The diagram is often used to study and understand an engine’s design and operation.Bearings: Connecting rods typically have bearings at both the big and small ends, allowing them to pivot and rotate smoothly. These bearings may be made from various materials, such as bronze or a low-friction synthetic polymer.
Supporting the weight of the piston: The connecting rod must be strong enough to support the weight of the piston and any other loads placed on it, such as the pressure of the combustion gases in the cylinder.Con-rod is an abbreviation for connecting rod. The con-rod mechanism on the crankshaft converts reciprocating momentum to rotating velocity. The con-rod connects the piston to the crankshaft, transferring combustion pressure to the crankpin.
Titanium connecting rods: Titanium connecting rods are made from titanium, a strong, lightweight, and corrosion-resistant material. They are often used in high-performance engines requiring a lightweight, strong connecting rod.
Many people mistake the piston rod and connecting rod for the same item; however, this is not the case. A piston rod is a distinct element that links to a crosshead, whereas a connecting rod attaches to the crankshaft directly.
A rod knock is a deep tapping sound produced by the engine. It is the result of wear or deterioration. Movement is hampered when the connecting rods inside the bearings of a vehicle have excessive clearance. When the piston shifts in direction, metal strikes metal, causing a knocking noise.
Converting motion: In many systems, connecting rods are used to convert the linear motion of a piston into the rotational motion of a crankshaft. This is essential in systems such as internal combustion engines, where the motion of the pistons must be converted into rotational motion to drive the wheels or other components of the vehicle.
What is a rod in an engine?
A connecting rod, also called a ‘con rod’, is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft.
Rod body: This is the main part of the connecting rod and is typically made from strong, durable steel. It has a cylindrical shape with rounded ends and is designed to withstand the stresses and forces applied to it during operation.
What is the function of a rod in a crank mechanism?
The con-rod connects the piston to the crankshaft to transfer combustion pressure to the crankpin.
Aluminum connecting rods: Aluminum connecting rods are made from aluminum, a lightweight and strong material. They are often used in engines that require a lightweight connecting rod, such as racing or small engines.
Why is it called a rod?
The word rod derives from Old English rodd and is akin to Old Norse rudda (“club”). Etymologically rod is also akin to the Dutch rood which referred to a land area of 40 square rods, equal to one-quarter acre, or 10,890 square feet (1,012 square metres).
The connecting rod is a critical component in an engine, as it connects the piston to the crankshaft and transfers the motion of the piston to the crankshaft. This motion is what drives the engine and allows it to generate power. There are several key functions of the connecting rod in an engine, including:Connecting rods are an important component in many mechanical systems and play a crucial role in the operation of these systems. Some of the key reasons why connecting rods are important to include the following:
