K-series Short Block Guide

foreign IQ fan for very long you probably know that I'm a huge proponent of the Honda K motor the K motor is one of my favorite engines because it has a huge amount of aftermarket support the cylinder head floats like no other and they can make a tremendous amount of horsepower and boost it or naturally aspirated applications so let's get into what we do with K Motors and talk about the insides so for our build we're going to start off talking about pistons and for us when it comes to the Honda K motor that's usually going to be a je piston you might want to know why we like je pistons for arcade builds well je has a piston for about anything you can dream up and it's a shelf piston that means it's off the shelf you don't have to wait for a custom piston and you know if you ever have a problem like you it's a race motor you need to rebuild the motor mid-season because something happened having a shelf fisting can be a lifesaver it's the difference between getting a piston like overnight and having to wait six to ten weeks to get one now like a lot of piston makers their shelf piston is like you just kind of got to take what they have but je has so many different combinations of k-series shelf Pistons that you really don't need the compromise anything Jay has more diameters for instance from the stock 87 millimeters all the way up to 94 millimeters now um when you bore one of these you really don't want to go past 87.5 because the liners not enough to accommodate a bigger War than that but you can always go sleeves and that's how you can get the really big bores compression ratio is also really important the Shelf Pistons you can get them in anything from 9.25 to 14.25 so anything from a good turbo motor to a shoot all the way to the top full full-on naturally aspirated build can be accommodated with shelf Pistons the je piston can also take any common combinations of stroke and Rod length off the shelf too so when you're starting off trying to decide what piston to run I guess you have to figure out what your end use is going to be is this going to be a turbocharged motor is it going to be naturally aspirated what kind of fuel are you going to run is it for a particular class of racing and are there any rules and restrictions I guess I can give you some rough guidelines for a turbocharged motor especially if you're going to be running pump feel it'd be a good idea to run the 9.25 compression ratio Pistons this is a fairly highly high compression ratio for a pump gas turbo motor but the K has a nice flat included angle combustion chamber with good Quench and good turbulence so it's pretty thin Nation resistant this will allow you to run a slightly higher compression ratio and have more Snappy response and better running off boost and with more compression you get on the spool a little bit quicker if you're going to be running like maybe ethanol or a really high octane race gas you can get away with as much as eleven to one in the turbo motor but um probably wouldn't push it more than that and when I'm talking about turbo I'm talking about you know it could be supercharged or it could be you're running a lot of nitrous any kind of forced induction you don't want to go too crazy in your compression ratio so I would say if you're running ethanol or maybe q20 or something like that VP or c16 you can get away with as much as 11 to 1. for naturally aspirated motor if you're going to be running on the street with pump gas you might want to run something like 12 to 1 ish you don't want to really go any higher with pump gas and with 91 octane that's pushing it then you're going to have to like be really concerned conservative with your tuning but if you run 93 in other parts of the country you can get away with 12 to 1. that's that's a pretty good compression ratio for you know like a pump gas naturally aspirated and if you're going to be running you know all out naturally aspirated motor and you're going to be running something like VP C12 or ethanol or something like that sure go for uh 14.25 get as much compression ratio as you can you'll get the best thermal efficiency most power widest Power Band there's diminishing returns like if you're going to be running on the street don't get too greedy with compression ratio I mean keep it to 12-1 and yeah just because the Piston is rated some compression ratio you can kind of tweak around a little bit uh you can Mill the head some deck the blocks um run different thicknesses of head gasket be a little creative with Alvin trouting all to get the uh volume up there or down there to tweak your compression ratios so you can do tweaking without being too detrimental for other things you know plus or minus half a point of compression that's pretty much how you choose the piston and I guess when you're choosing your compression ratio it's best to err on the side of being conservative just just run a little bit less hard than you think you might want to especially you know you Grassroots people that are on the budget and you don't want to hurt stuff so for your K motor you know you have your standard bore and there's limits to what you can do with your standard bore from the factory they say that the ten thousandths of an inch is about the max that you can do with OEM piston but uh you know we we can say that we comfortably bore up to twenty thousands and if you look here the cylinder liner is really thin and um you know you don't want to get too much into that um if you want to go bigger than that you can like have your block machined out for sleeves a lot of times we don't like doing that because you know if you take out the whole center part of your block you're if if sleeving isn't done correctly you can lose some structural integrity and you can have problems with head seal and things like that I mean basically you'll be turning your um engine into a case for for freestanding cylinders now if this is done correctly um you know a lot of horsepower can be uh contained like that but generally for a motor that is going to be something like Road raced or a lot a lot of different heat Cycles near the max we like to keep the Integrity of the block but that doesn't mean you have to so you can go pretty big in the bore um you know up to 90 millimeters with sleeves the other thing we like to do is um you take the minimum out of the bore as you can you know like let's say uh there's a lot of wear or um scratching in the cylinder wall or if somebody set the motor out with water in it and it got corroded um if it doesn't clean up with a 20 pounds overboard and then you know it's either time to sleep or get a new block so now we can talk about our specific recipe to kind of build a k motor now this is a pretty reasonable semi-low budget bottom in this will see you through plenty of horsepower and we can build one that could take even more horsepower but uh you know something like this can probably withstand 500 horsepower easily and it's a pretty reasonable in price some of that is the K block is really Stout this is a K24 block now the bomb in has this whole bed plate traditionally engines just had main bearing caps so each main bearing had an individual cap and um you know it wasn't unitized so that wasn't nearly as strong the key motor has this bed plate so all the main caps and the whole bottom of the engine are unitized in this one stiff super strong structure so this supports the crank really well it won't Flex even with a lot of power and is super stiff and it helps fortify the stiffness of the block that kind of helps Distortion overall can improve your life of things and even improve things like your ring Steel so when we do the block you know this block has a lot of our tricks done to it first off we do all our boring and honing with a with a flex plate the flex pay plate is a um steel plate that's machined like the cylinder head and you can assemble it with all the bolts or studs and fully torque it down just like the torque above bolted on head now when you pull on the head most blocks distort quite a bit and you know it can make the cylinder go out around by over a thousandth of an inch so you know I thousands of an inches quite a bit you know that's more than one third of your total twists in the wall clearance if you get that Distortion uh your piston rings aren't going to seal well there'll be some scuffing on your piston just everything won't wear as good so when you put the torque plate on and do all your Machining it's like Machining with the head on so when everything's torqued your bores are going to be perfectly round so that's good for power friction reduction and longer life so once we bore it this was a pretty crusty uh block and our customer didn't like it so what we did is we uh had it Vapor honed so um Vapor honing process is uh you get a special media and you basically blast the block with it and the media is blasted with water so the water acts like a cushion and a lubricant and it'll take off all the crustiness and leap like a luster so you know if you had sandblasted or bead blast it would be like this dough gray color it would be really porous so if you touch the engine with greasy hands you'd have fingerprints in and they wouldn't come off and it would look basically look like crap but um when you uh Vapor hone you get this nice luster and it looks like a brand new block that just came from Honda I mean you can probably see that in this front cover too now these things are really crusty they had a lot of white corrosion and a lot of baked on burnt oil and stuff but I mean when you look at it nice shiny brand new hard finish that doesn't leave fingerprints and dirt and oil and stuff will just wipe right off it's a really cool process after Vapor honing we did all of our machine work then we sent the block to get cryogenically treated and the boards WPC treated WPC we talked about a lot it's a like a Japanese micro shot painting where they blast the rubbing surfaces with a super fine ceramic medium that's super round it gives it a really smooth finish and the blasting kind of refines the grain changes the grain structure so it's a hard smooth finish that cracks don't propagate and it's really wear resistance when you do the things like your boards your board can probably last twice as long without having to be reboard it also reduces friction and your rings breaking quicker basically we do it on everything in the whole engine that rubs um crowd trading uh is like an extension of the Heat Treating process basically you take the engine down to the temperature of liquid nitrogen and hold there for a certain time and you cool it down and heat it up like very carefully so you don't distort the part basically that completely stress relieves the block and parts and it also in the boards kind of converts any kind of iron into a harder kind of a harder crystal structure so if you're in the Metallurgy it's changing austenite in the morning site um the aluminum it's a little bit of an extension of artificial aging so the elune gets a little harder and stronger it's a nice process for any engine that you want to last long and be reliable so we trial treated WPC Vapor hone and the last thing we did was we ultrasonically cleaned the block when you machine the block there's all kinds of shavings and cutting oil and residue that can get into bad places where you don't want them to be same thing with the vapor honing that uses a really hard ceramic media that can get in the places you don't want it coming out and WPC any of those things are abrasive and they can really damage the engine if they come out in use so when we've done all these treatments our final step is to ultrasonically clean the block now we go to this Aerospace place that specializes business and ultrasonic cleaning and what they do is immerse this thing in the tank bombard with ultrasonic waves it causes agitation and literally knocks all the particles out of the whole block they also pump the clean fluid through all the passages while undergoing this ultrasonic agitation it gets the engine surgically clean so if the engine's been subjected to a lot of different media we always do the ultrasonic cleaning before we reassemble it so what we have here is our basic bottom end assembly um you know this this thing can take like 500 horsepower all day and if you wanted to go full ham I mean we can build you one that could take as much horsepower as you dream up because there's all kinds of levels of stuff like there's build cranks Billet blocks you name it but for a reasonable budget what we have here is fine it'll be totally reliable and it'll pretty much kick ass we're going to start off with the stock K24 crank this is a nice forged crank it's fully counterweighted and it's nitride from the factory uh all we really did is balanced it we micropolished the journals cryogenically treated it and the WPC treated the journals this kind of crank can handle a lot of power it can handle probably like 80 85 8600 RPM totally reliably if you want to rev consistently higher than that we might want to put a trick or crank but there isn't too many situations where the stock crane can handle it I mean I really like the stock crank it's a good p peace and it doesn't take that much to make it really good for connecting rods we use the K1 Rod now this is a really good rod for the money it has a really good price that's the most important thing the rod is machined out of 4340 like a forging and what's interesting about this particular forging is it's a near-net shape forging so what that means is when this thing's forged they get a piece of metal put it in the dye and koam it with a ton of force and it comes out the big end and little end comes out now a lot of rods are cut from Billet and you know like you have your grain going you know usually this way which is pretty good but then your grain flow around your calf is still like that when you get this net shape foraging the grain flows down the beam but it also goes around the big end of the rod and that actually gives it a lot of strength and toughness without you know adding weight and all that um so it's a near-net shape forging that is uh has the final Machining there's some cool features the oiling holes are there's one here and one here uh they're on the bottom part of the rod a lot of rods have a big oiling hole at the top the reason why the having the oiling holes on the sides is important or why it could be better is um this is like a part of the rod on the top that's pretty highly stressed because you know the pin wants to yank out of the top of the small end you know when it's accelerating and when you remove material here that creates a weak spot so there's a lot more material around the base of the small end so having two small holes it can be better than having one big one at the top the rod bolt this is really important this is the most highly stressed part of the rod they're ARP 2000 bolts which is kind of the industry standard for a good rod bolt there are 200 000 PSI strength which is really good um you know it's good enough for quite a bit of horsepower there's trigger Rod bolts you can get if you want to go huge horsepower but ARP 2000s are way better than stock and they're good for ninety percent of the time another nice thing is the after Machining this Rod is solution Heat read it so that brings it up to a like a higher level of strength like what it'll do is all the metal in here gets the solid solution temperature and what that is is when it's actually the solid shape but scientifically I guess you could say it's a liquid solid alloying elements are all freely circulating around in the rod now when you're at solid solution temperature all the alloying elements are going to arrange themselves evenly throughout the rod and you can actually fix the crystal Matrix of the mill by quenching it at the right temperature and time so you can actually get a higher tensile strength and better fatigue Properties by quenching it and controlling the crystal structure of the metal to what you desire the final thing is that they do a severe shot peening we use a small shot and a big shot small shot gets into all the little tight radiuses and the big shot imparts a lot of the compressive force on the surface of the part so the shot pinion creates a a skin that has a lot of compressive stress and it also causes a lot of grain refinement on the surface so it makes the grains fine and tight and it's a skin over the whole part now when you have compressive stress and finely grained skin it's really hard for a craft to get started and propagate throughout the rod so what that means is the amount of cycles that the rod could take before it breaks is basically doubled with the proper shot peening I guess some of the normal things has a silicone bronze small end bushing which is kind of typical for a high quality Rod but most of all you get all this at a great price to hold the bomb in together we use ARP 2000 studs the studs are better than the factory Honda bolts that tend to get stretched out after one cycle of tightening the ARP studs have a strength of 200 000 PSI which is way more than stock and basically holds the bomb in together a lot better so the studs have like nuts with equivalents strength and they also have ground hardened washers so these are super flat washers really hard help you get a consistent torque reading when you're tightening them uh for bearings we use the king XP bearing we've had really good luck with the XP some of the cool things about it is um it's a tri-metal bearing so the um the main layer the overlay is uh lead but it has a high TIN content than the alloy although the tin makes the lead a lot harder it increases load bearing capacity so the 10 alone gives like a about a 20 advantage over your typical bearing material the other thing about the King Bearing that's cool is it has a black top coat now um coated bearings are not a new thing they're usually there to provide some lubricity if any part of the crank touches down during the operation it prevents the uh crank from getting into the softer lead overlay the big thing about the king coating is it has a five percent content of copper and Nano particles none of these copper nylon particles make it so the coating actually increases the load bearing capacity usually Coatings don't do anything for that so the cleaning gives you about another 12 percent more load bearing capacity so that's a king Innovation that works really well now we've had incredible luck with King bearings like we've run racing motors for a whole season take them apart bearings hardly look worn we could probably just like put them right back in if we wanted to um usually when you're doing actual racing like road racing or drifting where you're really on the throttle for long long periods of time there's usually significant wear after a teardown interval interval but uh King bearings seemed to hang probably better than other bearings that we've used in the past so of course like we talked before we're going to be using je Pistons with this engine this particular engine is going to be a hot naturally aspirated Street motor so the compression ratio we chose is 12 to 1. of course it's a shelf piston and there's no compromises here this is just as trick as the custom piston one of the things you might notice first is an asymmetrical skirt a lot of race Pistons have what you call a slipper skirt so that would be a skirt like this size it's a really small minimize minimalized skirt that's cut down to the minimum this gives the lightest weight least amount of friction but there's a lot of Point loading and a lot of wear so uh the J piston on the thrust side of the Piston that sees the most load you notice it's way wider so it's almost as wide as a full skirt piston so this kind of spreads out the load reduces wear reduces Rock in the in the bore which can make piston slap noises basically you get the best of both both worlds you get the support of a full skirt piston on the thrust side and you get the low friction and light weight of a slipper skirt on the non-thrust side that's not as loaded this forging that's used for the K motor was designed especially for the K motor so it's net shape is a really just about perfect so you don't need a bunch of uh you know after after Milling I mean there's some minor underground Milling to reduce some weight but it's not like you're you're starting off with this big ability thing that you have to carve the heck out of it basically a near-net shape forging with minimum under underground Machining that ends up being a uh more inexpensive it's a better when you have a near-net shape foraging you have better grain orientation and everything it's kind of a win-win a little extra is the J piston comes with a skirt coating um Alli friction coating that you normally have to send your piston out to a few months of these little pads here that's where your micrometer goes to measure your bore so you can set your piston wall clearance that's a good plus that uh you know it's a no cost extra the Piston pin is your standard uh steel pin we don't like to get too fancy uh a nice straight wall pin usually doesn't flex and doesn't give you trouble A lot of times in the past a tapered wall tool steel pin was the hot tip but we've kind of found that as motor's output has gone up more and more a tapered wall pin wants to like Flex under load and that tends to like catch on the small and bushing and spin it out of the rod that is not good and usually causes catastrophic failure another feature is there's a gas accumulator Groove between the number one and number two compression Rings the accumulator Groove helps get a gas pressure underneath the second ring under all times and improves your ring seal without increasing your attention the accumulator Groove is especially handy at high RPM a lot of high-end racing Pistons have this feature here and something that's come into play probably over the last 10 years overall I mean this is a really good piston it has a lot of features of a custom piston it doesn't give up anything to a custom piston and a best of all it's off the shelf so piston rings are important part of the Piston package a lot of people don't think much about them but the rings that je supplies to their shelf Pistons are like actually really high tech they're a low friction design that means they're really thin and also they're they're their thickness here is really thin in the old days these kind of rings were race only and uh they used to not last very long and they'd be a lot of leaked down they burn oil and it was a really Tweaky thing to try to do and you would do it with gas porting get pressure behind it but uh really low friction and other times but ring technology has improved so much that they're actually practical for long-term use the metal that's used in rings is a lot more sophisticated like you get a steel alloy better Alloys of um iron two in the second ring steel first ring better Metals than the scraper the number one ring is a steel ring it has a barrel shape and it's a nitrited nitrine they they cook these things and uh um atmosphere with like Cyanide and stuff and uh at high temperatures and then that causes um the the outer surfaces of the Ring to um have a lot of iron nitride form which is a really hard almost ceramic type um crystalline structure that actually penetrates into the ring like old school Rings maybe uh they may maybe they're a Chrome plated but nitriding is actually harder more durable and more slippery so with the nitride ring small has this slippery outside and really hard lasts a long time the number two ring is like a ductile iron what's trick about this this is it has what's called a neighbor profile a neighbor profile has like a little hook in there the hook actually kind of helps trap gas to put some more radial pressure into the cylinder wall for better ceiling it also has a really thin Edge that like wears into and conforms to the cylinder wall really quickly gives you fast break in most je Pistons have a neighbor second ring and you know like even though these are really thin really low tension really low friction Rings we've never had a durability or like a oil burning problem the oil rings man it's really thin like the separator is thin and the rails are like paper thin you know Jay's technology the super thin low tension Oil ring does its job like I said we never had a problem of excess oil consumption or lack of Life some of the tricks we do when we assemble an engine the entire rotating assembly is balanced we measure every single journal on the crank in several places that way we know the the true Journal diameter and if it has taper wear or if it's not around or anything then we assemble the bond then bring it up to torque and that way we measure the bearing bores for the main and that way we know your true bearing clearance we can adjust a little bit by massaging the crank or massaging the different bearing shells that we used so that way we get a nice consistent clearances for your bearings now most shops just throw that stuff together but you know we found that a lot of times you get tight spots it's a lot of friction that means there's a lot of wear because something is not straight now if we have like problems with that we align bore everything and get everything nice and straight and perfect controlling the main bearing clearances are important especially with modern aluminum block engines the thing is the aluminum grows so the clearance can grow with temperature and if you don't keep those bearing clearances like really really nice and tight you can start losing oil pressure and we've seen engines that other people build and they have almost zero oil pressure when they're idling and hot but you won't see that with our Motors we take a lot of time to get the clearance right we also machine the decks to make sure they're flat and we take out the minimum possible material and we also use a really fine finish so if you have an MLs gasket it'll seal no problem when we machine our boards we just don't tell the machine shops yeah take it out 25 over a lot of engine builders do that what we do is we measure each individual piston and we number it then we number our bores and we tell the uh The Machinist like how big we want each individual bore so each piston is fitted to its individual bore that way you get a lot of consistency that that's all helping life friction controls piston slap noise controls oil consumption it's uh it's all good another trick we do is we always get oversized piston rings and uh we actually blueprint each ring so the end gaps are perfectly the same for every cylinder we have a little little machine that we can grind the uh ring ring gaps and make them perfect but each each ring set is a hand hand fit for each cylinder so if you like this video and you want to see um like what we did with the top end and things like that for the top end generally we like working with drag cartel we like their cam grinds we like their head work so a lot of our top ends feature a dry cartel head this engine is pretty identical to project RSX on Moto IQ so if you go to moto iq.com look at project RSX we also had a build for a aerial atom with a very similar motor both of these motors produce more than 300 wheel horsepower with 91 octane SuperCraft California Gas they're pretty conservatively tuned and they're both still alive so if you want to know the part numbers of what we used here check out the description of this video they're going to be in there we'd like to thank J.E pistons and K1 rods along with ARP for helping sponsor some of this and uh hopefully you enjoy this video so if you want to see more go to moto iq.com read all of our hundreds and hundreds of articles that are highly technical there be sure to mash that subscribe button subscribe to this Channel and also visit us on Instagram and Facebook so until next time we'll see you later hopefully we'll be getting into more engine Tech

Channel: MotoIQ

Views: 152,573

Keywords: motoiq, je pistons, vapor honing, drag cartel, k1 rods, arp bolts, arp, head bolts, king bearings

Id: rSqNFNOTdGM

Length: 34min 32sec (2072 seconds)

Published: Sat Oct 08 2022