K1 - Blog
Verifying and adjusting bearing clearance is one of the most critical aspects of building an engine. In this segment, we dive into the mechanics of how to measure your crank, connecting rods, and bearings.The simple fact is that setting bearing clearance for a performance engine is something that cannot be short cut. There are no quick and easy ways to establish this critical clearance regardless whether the engine is a bone-stock cruiser or a road course animal that will endure hundreds of miles of abuse.
We will run through the basics on how to measure bearing clearance and illustrate how to avoid mistakes. This will also require some critical measuring tools. Let’s just put this right out front – measuring bearing clearance for a performance engine cannot be accomplished with Plastigage. Those little pieces of wax thread are not precision measurement dev
A successful engine build begins with the right components. K1 Technology’s rotating assemblies give you a head start with high-quality internals that are perfectly matched, with no guesswork.
There are guys out there who know it all by heart. Roll a freshly-machined block into their garage and they’ll order up the right engine internals with part numbers taken straight from memory. Want to bump the compression ratio? They know the correct combination of rods, pistons, and crankshaft to make it happen off the top of their heads. Are you looking to throw a little more displacement at the build? They’ll pull the appropriate part numbers for the slugs to match your overbore and a stroker crank out of thin air.
The rest of us? Not so much.
We’ll spend hours on the computer trying to figure out what mix of different parts will accomplish what we’re trying to do, and then second-guess that decision until it all comes together and (hopefully) works right. Your buddy says “use this piston,” the magazine article you read, tore out to save, then promptly lost in the stack of notes on your workbench recommended another brand’s rod, and all the bathrobe-clad keyboard wizards on your favorite car forum can’t agree on which crankshaft you should use.
It’s nerve-wracking, and another bead of sweat forms on your brow with each credit card digit you enter while you punch in the order for your mixed bag of parts. But it doesn’t have to be that way. There’s an alternative that removes all the st
K1 is flush with LS stroker crankshafts to take your block from boring to big-inch.
Ready to feel old? The LS engine turned 21 this year. If it were human, it would have a high-school diploma and could legally down a six-pack of beer. After two decades of LS swaps, builds, records, and race wins, it's as popular as ever, and there more of cores than ever to go around.
If you've picked up an LS core for your project, there's a good chance it has considerable miles on it. A bore, hone, and hot tank almost always work into the build plan, but what about the crank? The stock LS crankshaft is a stout and admirable piece, but one of the many strong points of the LS architecture is its taller deck height (over the gen I small block) and the ability to stroke it to torquier cubic inches.
That's where K1's line of LS stroker crankshafts come in. Currently available in 4.00in, 4.125in, and 4.250in, strokes, these longer arms can add invaluable displacement to your build. Better yet, they are also available as rotating kits prepackaged with the correct rods and pistons for an easy inch increase.
A Sum Greater Than The Parts
K1 built their reputation around crankshafts and rods that deliver quality at an affordable price, offering value that your average imported parts canâ€™t match. However, they've teamed up with Wiseco pistons to provide complete rotating assembly kits that pair professionally-matched components into a single part number to make ordering simple.
â€œWe currently offer Chevy LS applications as an off the shelf rotating assemblies,â€ K1â€™s Nick DiBlasi explains. â€œHowever, many of our customers make their own combinations with our pistons, rods, and cranks daily. We found it easy for our customers to pick and choose any combination they wanted and we could suit their needs.â€
Itâ€™s no surprise that the LS engine family would be the first target on K1â€™s radar for complete kits; factory blocks are so ubiquitous and cheap that theyâ€™ve become the hands-down favorite for racers and hot rodders looking for a solid foundation for a high-horsepower build. Though the stock LS components can definitely take a beating, upgrading the internals is a sure-fire way to create a durable, powerful race or high performance street engine.
Crank it Up
K1â€™s LS rotating assemblies start with a high-quality crankshaft, with a number of options. Both 58 and 24 tooth reluctors are available, and customers have a wide selection of crank throws from stock to stroker. Per DiBlasi, â€œThe K1 LS cranks are all forged 4340 steel and are designed for the latest demands of our customers. We offer strokes from factory 3.622 all the way up to 4.250, in 3.622, 3.900, 4.000, 4.100, 4.125, and 4.250 throws.â€
A nitrided finish improves crank strength and bearing life, and the large-radius fillets remove potential areas of stress concentration and potential failure. K1 employs a straight hole oiling system for superior bearing lubrication, and tolerances are held to plus or minus one ten thousandth of an inch.
The second ingredient in the successful recipe is a robust connecting rod, and K1 has that covered as well. â€œWe offer our K1 H-beam 4340 forged rods with our kits,â€ DiBlasi explains. â€œThey are designed specifically to be matched with our crankshafts and clear all the stroker applications. They feature ARP2000 bolts and have seen over 1,500 horsepower on many of our customersâ€™ race cars.â€
Many racers will debate the relative benefits of an H-beam versus an I-beam design in terms of ultimate strength, but for applications where shaving grams isnâ€™t absolutely critical, the H-beam delivers additional rigidity and better load distribution than a comparable I-beam connecting rod, and makes perfect sense for K1â€™s rotating assembly kits. Dual reinforced ribs add strength on the big end, while radiused sides maximize clearance. A shot peened finish is the finishing touch, placing the outer surface in compression and removing any potential locations for stress riser formation.
Slugging it Out
When it comes to pistons, Wiseco offers a wide selection, no matter what bore or compression ratio youâ€™re shooting for. Per DiBlasi, â€œOur main rotating assemblies come packaged with Wiseco pistons. We offer various popular compression ratios based off the combinations we know work best.â€ Depending on combustion chamber volume, the shelf stock LS rotating assemblies range from 9.3:1 to 13.0:1, suitable for boosted or naturally aspirated builds.
Wisecoâ€™s Professional Series forged pistons also utilize their proprietary ArmorGlide skirt coating that reduces friction, increases horsepower, and improves wear resistance. â€œIf you are looking for a compression ratio that we do not offer [in a stocking part number], we can gladly build a rotating assembly with the same components and another piston combination that we offer,â€ DiBlasi adds.
When you order up a rotating assembly from K1, youâ€™re getting all the other matched components you need to round out the engine internals as well. â€œThey come with pistons, pins, locks, and rings,â€ DiBlasi explains. The goal is to provide everything you need under a single part number, so that you can order with confidence, knowing that there wonâ€™t be any bits and pieces that you need to figure out before you start putting everything together. â€œAll of our kits come with rod and main bearings,â€ he adds.
â€œOur kits are designed to go together and have been tested on our in-house dyno,â€ DiBlasi says. â€œWe have an in-house engine dyno just for LS-based engine testing. Everything was designed to work together. We take the work out of ordering parts from different places, and do the testing for you. Creating rotating assembly kits for the LS family was simply a no-brainer."
Posted: November 13, 2018
LS engines are all about interchangeability and swap-ability. K1's line of LS7 crankshafts makes it possible to add factory dry-sump oiling to any Gen III/IV LS engines.
K1 Technologies is now helping resolve one of the more frustrating idiosyncrasies of the LS engine platform; that is, GM’s switch from 24 to 58 teeth on the reluctor wheel. Now that millions of LS engines and parts are in the salvage yard, available at swap meets or posted in online classifieds, the difference in the reluctor wheel can limit creative vehicle builds or engine swaps. One such option is adapting LS7 dry-sump gear to a Gen III block.
What’s a reluctor wheel got to do with the oil system? The LS7 crank has a snout longer than a standard LS engine. This extra length is needed for the differences in the LS7 dry-sump oil pump, balancer, timing set and front cover. However, the factory LS7 crank has a 58-tooth reluctor wheel while the Gen III vehicles are equipped with an ECU that recognizes signals from a 24-tooth wheel. The only way to make such a swap is to replace the 58-tooth rel
Engine building is all about the details, and choosing the right set of engine bearings to match your crankshaft is an important one! Inside we investigate what a narrow bearing is and when you should use them.
It seems every day that there is a new post on social media about street engines making four-digit power. A killer late model Hemi with a blower easily pushes past 1,100 horsepower and Mike Moran has built an all-billet, twin-turbo engine that made 5,300 horsepower. The power numbers keep escalating and yet far less attention is paid to what it takes for crankshafts, pistons, and connecting rods to survive these ever-escalating, and easier-than-ever-to-achieve power levels.
Deck height is a vital engine measurement that dictates rod length, crankshaft stroke, piston-to-head clearance, and so much more. Here, we define deck height, how to measure it, and its impact on your next engine build.
It’s all part of the art of building a performance or competition engine. The details separate the exceptional from the also-rans. Some specs like rod and main bearings receive a majority of the attention, but ignore something as simple as deck height and you could find a piston smacking the head at high rpm is not a good way for reciprocating parts to become acquainted.
This really isn’t a critical dimension if a standard rebuild is the goal. But if you’re a performance engine builder and stroker cranks, longer rods, shaved decks, and custom pistons are your thing – then block deck height is an important dimension that demands attention. For the record, deck height is the distance between crankshaft centerline and the top of the block.
Planning a stroker build? Here are a few things you should know before you get started.
It wasn’t all that long ago (okay, LBJ was president and Bonanza was a hit TV show so maybe it was a long time ago) that a factory 327 / 350 hp small-block has serious street cred' and Chevy’s 427 making 435 horsepower was boulevard king. Today, it’
Our friends at Moto IQ show you how to build a Coyote engine within your budget!
Fords Coyote engine, a 32v, 5.0L mill found under the hoods of Mustangs and F150s alike, has proven itself time and time again as a power dense, and highly swappable platform. Our friends at Moto IQ take a walk through the Coyote lineage, production variants, and build options to give you a game plan to build a Coyote engine to meet your power and budget requirements.
Read the whole story HERE!
Small changes offer big benefits when it comes to selecting aftermarket rods for your next Chevy LS engine build. Here’s a look at how rod length affects the performance and durability of an engine - and you thought you’d never use that Geometry you learned in high school!27 thousandths of an inch doesn’t sound like much. It’s about the thickness of a multi-layer steel head gasket typical for 4 cylinder applications. It’s almost exactly half as thick as a dime, which mics out at 0.053 inches. It’s a bit smaller than you might gap your plugs on an old-school points ignition small block Chevy. But like everything involved in high performance engine building, tiny fractions of an inch make significant differences in horsepower and durability, and that’s why rods that are ever so slightly longer than “factory stock” have become a big deal in LS engine builds.
An intense look at crankshaft stroke and its affect on mean piston speed, inertia, and controlling the massive, destructive forces at work inside an engine.Engine builders have long calculated the mean piston speed of their engines to help identify a possible power loss and risky RPM limits. This math exercise has been especially important when increasing total displacement with a stroker crankshaft, because the mean piston speed will increase when compared to the standard stroke running at the same RPM.
But what if there was another engine dynamic that could give builders a better insight into the durability of the reciprocating assembly?The video above shows two engines, one with a short stroke crankshaft, and the other with a considerably longer stroke. Note that both pistons reach top dead center and bottom dead center at the same time, but the piston in the longer stroke engine (left) has to move significantly faster.
â€œRather than focus on mean piston speed, look at the effect of inertia force on the piston,â€ suggests Dave Fussner, head of research and development at K1 Technologies.
Letâ€™s first review the definition of mean piston speed, also called the average piston speed. Itâ€™s the effective distance a piston travels in a given unit of time, and itâ€™s usually expressed in feet per minute (fpm) for comparison purposes. The standard mathematical equation is rather basic:
Mean Piston Speed (fpm)=(Stroke x 2 x RPM)/12
Thereâ€™s a simpler formula, but more on the math later. A pistonâ€™s velocity constantly changes as it moves from top dead center (TDC) to bottom dead center (BDC) and back to TDC during one revolution of the crankshaft. At TDC and BDC, the speed is 0 fpm, and at some point during both the downstroke and upstroke it will accelerate to a maximum velocity before decelerating and returning to 0 fpm.
There are formulas to calculate the piston speed at every degree of crankshaft rotation, but thatâ€™s usually much more information than needed by most engine builders. Traditionally they look at the average or mean piston speed during the crank rotation, and they possibly will calculate the maximum piston speed.
The mean piston speed takes the total distance the piston travels during one complete crankshaft revolution and multiplies that by the engine RPM. Piston speed obviously increases as the RPM increase, and piston speed also increases as the stroke increases. Letâ€™s look at a quick example.
A big-block Chevy with a 4.000-inch-stroke crankshaft running at 6,500 rpm has mean piston speed of 4,333 fpm. Letâ€™s review the formula again used to calculate this result. Multiply the stroke times 2 and then multiply that figure by the RPM. That will give you the total number inches the piston traveled in one minute. In this case, the formula is 4 (stroke) x 2 x 6,500 (RPM), which equals 52,000 inches. To read this in feet per minute, divide by 12. Hereâ€™s the complete formula:
(4 x 2 x 6,500)/12=4,333 fpm
You can simplify the formula with a little math trick. Divide the numerator and denominator in this equation by 2, and youâ€™ll get the same answer. In other words, multiply the stroke by the RPM, then divide by 6.
(4 x 6,500)/6=4,333 fpm
With this simpler formula, weâ€™ll calculate the mean piston speed with the stroke increased to 4.500 inch.
(4.5 x 6,500)/6=4,875 fpm
As you can see, the mean piston speed increased nearly 13 percent even though the RPM didnâ€™t change.
Again, this is the average speed of the piston over the entire stroke. To calculate the maximum speed a piston reaches during the stroke requires a bit more calculus as well as the connecting rod length and the rod angularity respective to crankshaft position. There are online calculators that will compute the exact piston speed at any given crankshaft rotation, but hereâ€™s a basic formula that engine builders have often used that doesnâ€™t require rod length:
Maximum Piston Speed (fpm)=((Stroke x Ï€)/12)x RPM
Letâ€™s calculate the maximum piston speed for our stroker BBC:
((4.5 x 3.1416)/12)x 6,500=7,658 fpm
By converting feet per minute to miles per hour (1 fpm = 0.011364 mph), this piston goes from 0 to 87 mph in about two inches, then and back to zero within the remaining space of a 4.5-inch deep cylinder. Now consider that a BBC piston weighs about 1.3 pounds, and you can get an idea of the tremendous forces placed on the crankshaft, connecting rod and wrist pinâ€”which is why Fussner suggests looking at the inertia force.
â€œInertia is the property of matter that causes it to resist any change in its motion,â€ explains Fussner. â€œThis principle of physics is especially important in the design of pistons for high-performance applications.â€
The force of inertia is a function of mass times acceleration, and the magnitude of these forces increases as the square of the engine speed. In other words, if you double the engine speed from 3,000 to 6,000 rpm, the forces acting on the piston donâ€™t doubleâ€”they quadruple.
â€œOnce started on its way up the cylinder, the piston with its related components attempt to keep going,â€ reminds Fussner. â€œIts motion is arrested and immediately reversed only by the action of the connecting rod and the momentum of the crankshaft.â€
Due to rod angularityâ€”which is affected by connecting rod length and engine strokeâ€”the piston doesnâ€™t reach its maximum upward or downward velocity until about 76 degrees before and after TDC with the exact positions depending on the rod-length-to-stroke ratio,â€ says Fussner.
â€œThis means the piston has about 152 degrees of crank rotation to get from maximum speed down to zero and back to maximum speed during the upper half of the stroke. And then about 208 degrees to go through the same sequence during the lower half of the stroke. The upward inertia force is therefore greater than the downward inertia force.â€
If you donâ€™t consider the connecting rod, thereâ€™s a formula for calculating the primary inertia force:
0.0000142 x Piston Weight (lb) x RPM2 x Stroke (in) = Inertia Force
The piston weight includes the rings, pin and retainers. Letâ€™s look at a simple example of a single-cylinder engine with a 3.000-inch stroke (same as a 283ci and 302ci Chevy small-block) and a 1.000-pound (453.5 grams) piston assembly running at 6,000 rpm:
0.0000142 x 1 x 6,000 x 6,000 x 3 = 1,534 lbs
With some additional math using the rod length and stroke, a correction factor can be obtained to improve the accuracy of the inertia force results.
Crank RadiusÃ·Rod Lenth
â€œBecause of the effect of the connecting rod, the force requi