Heyho Folks, Rock’n’Roll. Welcome to part 2 of initiating engines last time we stopped at the rings diameter and comparison between the car pistons and bike pistons. In the second part we’ll get to another important detail: the cylinder so let’s start this video with the cross-grind. cross-grind, most people heard of it, just look at the inside surface of this cylinder. i’ll zoom-in a bit. So, yeah, I hope you can see it. The cylinders are coated with a Nickel-Silicon-coating. Then they are treated with special diamond grindstone and get this cross hatch, not a normal straight grind, but a grind that crosses each time it is applied in a certain angle. So why do we do this? Let’s zoom out. cross-grind, A) of course the oil needs a big surface area to stick to so the piston is well lubricated on the pressure sides if the surface would be smooth, the oil would just run down again. But the main function of the cross-grind is the ringrotation. The PDF says: to run and seal a pistonring, it has to turn in the ring groove. The ringrotation is caused by the cross-grind, structure and the piston tilting at the top and bottom dead center. a flat grinding angle causes less rotation and a steeper angle causes more rotation and therefore more turns per minute. the ringrotation is adjusted by the engine rpm, 5 to 15 rpm are realistic just to give you a feeling for the ringrotation not only by the oil but by the cross grind, the rings start turning and of course the turn at the tilting at the TDC or BDC. And now i’ll show you why the rings should turn. so let’s have a look at the profile, here is the piston, here are the pistonrings and here you see the arrows how the piston is tilting the PDF says: the rings normally don’t move radially but the piston moves from one side to the other within the cylinder bore this happens at the TDC and the BDC. that causes a radial movement of the ring within the ring groove. this grinds down the oil coal, the cross-grind helps grinding down the oil coal as well as the ringrotation. Let’s sum up the piston movement and the cross-grind, is causing the ringrotation depending on the angle. We have a combustion and the combustion gas is sliding past the piston and presses, I’ve already shown you how that works. of course oil coal and other byproducts are created and to prevent a blockage or the famous ring stopper, so the ring gets stuck in the groove leading to compression losses, the ring turns and is always moved free. So let’s go on! Good, now that we know how the rings turn, it’s important to assemble the rings, so if they all turn the same way, they don’t overlap with their gaps, let me try to show it to you the gaslabyrinth we talked about in the first part, would be useless, meaning the combustion gas and flames would just rush down this side if all the gaps were in the same place, and we would see compression losses, and the flames rushing down the side would harm the piston so we have to prevent this by using the ring setting that is rotated by 180° in the first place. But every piston manufacturer has there own recipe, piston rings with a 3-part oil scraper also rotate the upper rings from the lower rings let me show you the assemble of the Wössner piston. you can see the preset that Wössner wants. top ring with the Oil Rail Top Gap should be in driving direction in front on the left side, below that in driving direction on the right, both compression rings the minute ring is rotated against the compression ring on the axis of the piston bolt and the Oil Rail Expander Gap, the 3-part oil scraper where both noses should meet on the pressure side of the intake side. you see: everything is pre-set let me zoom out, many manufacturers are different but still somewhat similar. GE Piston wants the grooves, let me check, where is the back, where is the front? here is intake there is exhaust, the oil scraper, both grooves one over here and over here and both rings alined with the piston bolt. Let’s get to the next important topic. Ring twisting, funny word, but what’s that fuzz about? You’ll see now. So another movement by the piston ring is the ring twisting. caused by mass forces and ring height play the ring moves as displayed. The PDF says, This is Ring twisting. with this twisting the cylinder side will get rounder over time. As the piston moves up and down the ring twists to the other directions and wears off so it gets rounder. Wearing off is another subject while initializing an engine but we will get there in a bit. When talking about ring twisting I could tell you 2 hours of stuff but that would be out of bounds maybe we will talk about it at the end, but now one of my favourite subjects, most of you know: oil thinning. oil thinning is always a problem around cars because most people use it short range, grandma or mum just drive to the next super market and back and maybe that are 3 km per day but it doesn’t get really warm. it always runs in cold start mode and you get fuel into the oil. Well, at bikes you don’t usually drive short range, you’ll drive all day and of course the bike getting warm. unless you just use it to get buns or cigarettes or whatever. well you shouldn’t use it short range, but that’s another subject, oil thinning, yes, but regarding KTM we have to talk about mappings. first of all every injector and every carbo has a cold start function. you have a pin in the carbu you have to pull and at small bikes there are even electrical cold starters, which run up and down. an injector will get this via the control unit. you start, the control unit sees we have water, air, we have this temperature so we will fatten the mixture by a certain amount. eine bestimmte Menge plus an, 100% would be around 80° water temperature, when we are off by 5° either above or below the control unit gives or takes an extra 25%. at a cold start we have 125% at that mixture gets slowly less over time the warmer the engine gets. we don’t have this problem because we don’t always drive the cold start tour for 5 minutes when we drive we start once and then drive all day on a weekend the nearest track with our friends. the problem is: many mappings, of course i am talking about KTM, many maps especially evo 1 maps are very very very very fat. and if you just bought a flamenew KTM, opened up and tuned a bit, with Accrapovic, evo 1 and on the track, you have this oil thinning nearly permanently, because this is a racing map, i have already talked about this in another video, see up here and those are VERY fat. you have a extremly high fuel value and if you are running the original 10w i am not telling any brands, but we all know what brand the manufacturer wants. this 10w oil is thinned out in no time, so we get problems on the pressure sides. how that looks i’ll show oyu now. on the left you see well lubricated cylinder and on the right a thinned out, destroyed lubrication layer. Let’s have a look at the PDF: “after damages cause by dirt, oil thinning is the second most cause for damages of piston rings. the oil film is damaged by the fuel entry so the rings are grinding down the cylinder and lose radial thickness. Metalic contact of the piston rings to the cylinder wall; picture 4, the oil film gets too thin and we get a direct metallic contact area between the ring and the cylinderwall and only very short and in emergency e.g. during a coldstart and must not occur otherwise. the lifetime of piston and rings is shorted by quiet a bit. normally both parts are seperated by oil instead of metal on metal contact, picture 3 should show this oil between, the oil has to be thicker than the uneventies of the surfaces. as well thicker than the hohen-layer or the cross grind and therefore the piston can glide on the oil cleanly. While the motor is running fuel is condensating on the cylinder wall due to combustion mistakes. Let’s scroll down a bit, the oil layer get so thin or washed out, that the mixture friction grinds down the piston rings within a couple 1000 km. The performance drops and the oil consumption rises. mixture friction leads to a strong radial wear off at the piston rings and the cylinder surface. this is easy to see at both scraping edges of the oil scraper.” Let’s have a look and talk in detail about it. We talked about this problem back in #11 Pirate.Tv, didn’t watch it? click the link up there! We had Alexander Hornof as our guest because of the subject oil or rather oil thinning at KTMs but in general this is accurate for every 4 stroke engine car or bike doesn’t matter, it’s different from manufacturer to manufacturer and our experience with the company from austria with 3 characters is VERY special, it got better lately, the latest Evo maps were okay but still, if you don’t watch out you have oil thinning and that leads to strange engine failures, like a shattered con rod bolt, cylinder roll bearing, Inner rings, there is no heat signature at all, you don’t see a thing, just the hardened layer shattered away, no one knows why. So we always conducted oil analysis at Motul as shown in #11, every time such a damage was recorded and everyone had a questionmark on their face fuel was over 5% in the oil samples. we restored a lot of engines and gave them a new map, and reduced the fuel amount to a somewhat reasonable amount and oh wunder, they are still running. of course we are continously measuring where are we, are they still too fat? can we still go lower? but in the end we were at 1.9 1.5, 1, just below 2% and below 2% we can say as a long time experiment, you are fine. anyway we are still recommending on the 96 SMCR, to change the oil after 5000 km. oil thinning is still oil thinning even if it’s just a bit. the more you drive with the same oil, the larger the fuel amount gets you might think, the engine gets hot eventually and it vaporizes, but no not with these models the high volume single cylinder has too small amounts of oil – 1.7l is not much and the venting is not really significant. just to be on the safe side doesn’t matter what brand of oil, change it after 5000 km. it’s better and even if you don’t drive your 10000km, it’s just one more change, 2l and an oil filter, that’s not too expensive. I don’t have a comparison to other manufacturers, especially the japanese, but my guess is that they are burning through oil as well injectors and motocrossing eg and the maintainance is a lot higher. Motocross bike are driven on the weekend, maybe another weekend and then you already change the oil and check airfilter and so on und sofort, the load is really high, so you don’t really see these problems. and of course don’t forget the most japanese Motocross/Supermoto bikes, if they still exist have very large roller bearingshaben as their crank shaft bearing and also a lot of slide bearings on the con rod, KTM finally has those too, especially the new Euro4-engines Duke and 701 have all the same parts at the con rod, which is one part less that can break easily but the cylinder roll bearings are still there. Now let me show you some damages that can happen. here are some parts that you can watch out for while initializing an engine when you do it at your home. very important the oil scraper, we already talked about them. let me zoom in. here you see a new Wössner piston for a 450 SMR YoC 2010 this one has a 3-part oil scraper and just one compression ring, that is a racing piston. those don’t have minute rings. But, important is as you can see the ring spring, rather the wave spring of the 3-part oil scraper and there you can see the noses, i marked them with white paint those have to touch, this is very important, because if this spring overlaps there is no tension the scraper, isn’t pressed against the cylinder wall and are not worn off so they don’t do their job because of the missing tension I’ll show you what happens next. a little further back. Have a look. This is a piston of a 450 XCR, YoC2010 the model with the seperated oil circulation and here the problem, was a mistake during assembly the piston was run very little kilometers and the oil scraper was mounted the wrong way, the noses are overlapping and therefore the little oil that was in that crank shaft circulation, only 0.6l was gone into the combustion chamer, I think he got to the gas station an back and the piston was broken because there was no oil left, everything burned that slipped past the scraper Aluminium grinds on Nikasil and the temperature climped until the piston jammed on the pressure side near the exhaust valve. there are the highest temperatures, piston gone in no time. Let’s zoom out. If you decide to do this on your own, be very careful that you mount the rings in the right way. here another interesting case, about our topic or rather bike the 96 SMCR a piston of a YoC 2015 96 SMCR and a classic, high oil usage. nearly a liter on 1000 km, engine was still running fine and you can see the oil scraper broken. of course wie have to places the oil can slide through to the combustion chamber, but this part was especially unlucky those oil scrapers as we talked about in part 1 of this series, have an top and bottom side, on of which is angled, there are rings that don’t matter but those are for cars. this one only has one phase on the top, so it has a top marker, because the phase always has to be on top. unfortunatly this ring was marked the wrong way. maybe someone made a mistake while preconfiguring the ring, this error was seen at aroung 30.000 km so it was a ticking time bomb, engine worked fine but the cylinder was worn off fortunatly we opened the engine early enough due to the broken ring and therefore high oil usage. it would have probably run even more if the ring was assembled the right way. but if that was the deciding factor we can’t say for sure. the higher the oil usage the more likely it gets that the oil scraper gets oil stuck behind the ring. the oil that is meant to be scraped off, doesn’t get scraped and gets stuck behind here, it gets too much and fills the groove. that’s a liquid that can’t escape. the ring is under pressure from the outside, but it can’t twist anymore due to the stuck liquid and when the groove is filled up completely the ring gets broken by its own twist. That’s not very common but it’s a mistake that happens in those parts. sometimes we can’t really tell what the cause was and then the customer told us the oil usage was always a little higher than usual and then went extremly high maybe because the ring broke and yeah if you don’t react quickly to this, you have a capital failure, oil gone and so is your hardened layer. Good, to the next topic. We are back and sorry i got myself lost in engine and piston failures and KTM specific problems we didn’t make this video for that so let’s get back to initializing. especially eingines, or rather single or double cylinder engines and so let’s sum up, what we learned so far we know for sure the rings don’t fit perfectly perfectly from the beginning not all 360° touch the cylinder and the heat can’t be transferred so we need some slower testdrives to get the rings touching all sides. of course not going full throttle so we don’t get burned spots. the contact areas have to be worn off. You’ve seen the profile the contact areas need to get round slowly. So let’s start first point: drive without load. keep the engine in a rpm range, doesn’t matter what gear just make it easy for the engine. who drives enough bike knows what i am talking about, i made some notes. when you drive too slow, until the chain is stomping you have the same effect in the piston as with high load the lever gets too long, the gear to long and the con rod starts stomping which gives extreme loads on the piston floor and the fresh rings, the crank shaft but also the rings keep the piston stable when you are stomping, and the fresh rings can’t do that so please be careful not to drive with too low rpm very high and very low rpm values are not good for the single cylinder. and of course, don’t go max rpm, last gear, full throttle and see what the bike benches. we want to evade that because of the extreme heat this would cause and we know we can’t transfer much heat due to few touching points the fresh rings can’t handle it. so we just drive in the load free rpm ranges to make it easy for the engine, now i get to a mountain in 5th gear so we just go down one gear and keep 4500-6000 rpm no problem. or 7000 for a short time when driving past another car when we are already warm just shortly fast and back to loadfree mode, that’s the most important thing when initializing engines, and that’s important for every engine and therefore our number 1 priority. let’s go to #2, avoid coldstarts what do i want to tell you with this? easy: the longer the initial run is the better block yourself 1 or 2 weekends and save it for initializing. fill the tank, onto the bike and drive all day. Long and many km in one run so the engine doesn’t stop much. no short distances not 40 km to a friends house and back, doing it 10 times getting 400km. Not that would be the worst way just drive a lot of km in one go so the engine has a nice temperature without load and everything is good the more cold starts you have in the initializing phase, the worse it gets, we have learnd cold start correction, much fuel is injected, which is unnecessary because the engine is cold. Then the engine has to run in choke mode and we want to prevent this at all cost during the initializing phase. So take your time. Just tell yourself the weekend is blocked for the bike, girlfriend stays at home and drive it load free. third point, do not permanently use the same rpm. So, what does this mean? don’t use the highway and i am driving from Hamburg to Munich, then i have 700 or 800 km and drive with 120 km/h and 5000rpm but we need many changing rpms just drive your home track, many curves, many gear changes, this is optimal so the ring gets moved and gets different pressures change between low and high rpm ranges. it’s better for the ring and of course for the heat transfer. let’s get to #4. after 1000 km the first inspection. already after 1000km? Sure? 1000 km is just a rule of thumb. the engine might be initialized after 800 km but you have to draw a line somewhere and that’s why i say 1000 km, very important: change oil and filter because the abrasion is high with a fresh motor so the abrasion is bound in the first oil filling and that needs to get out of the oil coupling and so on. so: high abrasion therefore 1000km and to the inspection you go. to the merchant, oil and filter out and of course do the other prescribed tasks the manufacturer tells you eg configuring valves is not necessary anymore for the modern engines, most manufactures have abandoned that from maintainance, so it’s mostly just an oil change and seeing if everything is tightened. with new engines this is important, but even more important for renewed engines, of course we don’t have such high quality standards with renewed engines, the past has shown us that we have not those standards especially when renewing the valves, or rather the valve socket and valve cone are being grinded the valves may settle after 1000 km so if you have a renewed engine, please do an inspection after 1000 km; oil change and check the valves the newer engines, fresh from the manufacturer don’t need the valve check. let’s go back to the MS Motorservice PDF and read what they say “initializing of new engines is not necessary.” what else does it read? “New engines are produced with the most advanced technology, parts are being preconfigured in a way that they would have during engine initialization.” to shorten it, we don’t need initialization because cars are build with such a high standard they don’t have to adjust the parts by driving carefully. Because these vehicles have to reach their performance and emission values right at the merchant, so the engines are produced as desired. and don’t forget an initialization would be deadly for those engines they perform up to 150 coldstarts, depending on where they are being shipped, somewhere to the US or Australia, they turned on the engine 150 times already are driven 500m and turned off again. and of course, cars aren’t driven at their maximum performance, mostly we are stuck in a traffic jam, or driving through the city instead of going maximum velocity, Except you are living close to Nürburgring and can afford it. The buffer for cars is huge, due to the wear off until the car is at the customer, initialization is taken off the list if you renew a car engine that’s a whole different story because the new engine have higher standards than someone who renews it could ever reach. For a used and renewed car an initialization phase is recommended. talking about bikes this is different a bike, single or double cylinder, can be brought to its peak performance on weekends once in a while therefore initialization is important for motorbikes. I have shown you the single cylinder have extreme large piston diameters, short strokes, high rpms, high slide-rpms. throttle closed and the piston starts wobbling, the pistons are very short and have little guidance. But that’s all for now I could make an extra special video of course talking about our KTM stories. I’ll have a look on what’s doable but for now, we are done. I hope you liked it, I hope you learned some things about what to do with a newly bought bike and i would say, if you liked it, leave a like, leave a sub and we’ll see us next video, certainly Pirate.tv #18 with some interesting subjects if you have any questions about initialization just post a comment, the PDF is linked in the describtion the YouTube channel MS Motorservice is linked as well, check it out, it’s well done and as always, until soon, ciao.