| Author | Message | ||
     Jasonl |
Airborne - I've heard that motor would have a *Really* hard time passing epa regs. Not sure it was from noise or pollution but either would keep it off the road I think. | ||
| José_Quiñones |
The VR100 was not designed with EPA Noise regs in mind. It would be difficult to make it EPA noise legal without neutering it... | ||
| Airborne |
I'm suprised that nobody has comments about the Electro-Magnetic accutated valve system. Jasonl and Jose your both right but there have been other motors in history that have been detuned from racing to street legal standards. I'm sure Harley has it's own reasons for not releasing the VR1000 style motor other than EPA. In the 1920s Harley had it's 8 valve racer over priced so that only the factory race team would have them. Then there is the opposite side to this. Look what most of us have done with our Buells by swithing pipes, air box mods, race ECM (clearing marked in the catalog "racing use only") Then there is the puke can. All EPA violations. Wouldn't most of us do the same to the VR1000 motor if a street legal version was available. I would. | ||
| Ralph |
Airborne, very true. But as time has passed the regulations have become tougher to meet, even for existing motors that passed easily in the past. For instance, the motor in your bike. bighairyralph | ||
| Airborne |
Ok Ralph, you have my full attention here on this one. Lets assume you looked at my profile and noticed I have the 99 X1 and lets assume that everything is still stock. (not) What part of the EPA reg would the bike not pass? Noise, exhaust emissions or other? You've got me really curious now. | ||
| Blake |
I just learned something new... polishing imparts residual tensile stresses (very bad for fatigue) to certain metalic parts (I'm guessing more so for forged parts). Ralph, does it make any difference what lotion... err I mean compound is used? Blake (still working on that new solid piston-ring design) | ||
| Al_Lighton |
Blake, Mark_in_Ireland said that in the pictures section... Mark, Can you cite references? I'm really curious as to why that would be so. If you had a part that was already peened, and then polished it, I could see how you could essentialy polish away the effect that the peening already had done. But actually adding surface stresses from polishing seems kinda wierd to me. Seems like the smoothing of the microcracks that fatigue propagates from would be enhanced by polishing, not detracted. I guess that maybe there is some surface smearing that occurs? I'm not doubting you, I just want to understand the mechanics of it. I'm completely ignorant on the subject and you've got me curious. True for all metals or just ferrous alloys? Al | ||
| Ralph |
Airborne, read my post again. I didn't say your motor doesn't pass as made. Simply that an older model of the same motor, say ten years ago would not pass today. Check out the parts book and the number of cams available. All the same grind, just different size gears. Done simply to keep the noise down. If you ever heard an old Sporty grinding away you would see-hear why immediatly. Blake, from what I understand when you polish you are also work hardening. I don't think grinding has that effect but polishing with an abrasive wheel like I did with the rods or with a buffing wheel will. I don't think shot peening does anything to relieve the stress, it would "even" it out. Lets face it, shot peening is hammering, which in my world hardens steel to a certain degree. The only real way to "relieve" any stress built up is to heat cycle the piece. Guess what happens tomorrow? Mm, hm, heat will be applied. Now, all that can be the basest kind of bull. But at the same time I know for a fact 4340 can be work hardend. So, the easy thing to do is treat it real nice and do what I'm told by people who know way, way more than I do. bighairyralph | ||
| Blake |
Al, thanks for adding the credit. I was preoccupied with razzing ole BHR for polishing his rod like that and then posting a picture of it fercrisakes. I can especially see how a forged part's inherent residual surface compressive stresses might be relieved by the force and heat of a polishing wheel/compound; most cast or machined surfaces however can't get much worse as far as susceptability to fatigue goes. | ||
| Blake |
BHR, shot peening is used to impart residual biaxial (in all directions tangent to surface) compressive stresses into the surface of a metalic part. It is used extensively on aircraft structure to increase the allowable fatigue stresses on portions of some structural parts by up to 25%! The basis for this is that a crack cannot grow in compression. Another interesting way that some airframes were imparted with residual compressive stresses to fight fatigue failure... The aircraft was purposefully taken just past it's design limit loading conditions thus yielding tensile surfaces; after yielding, the tensile surfaces would be left with residual compression, especially at the root of any existing microcracks. I've heard some airframes were tied off at the tail while the engine was run WOT with prop pulling for all she was worth; that may have been as much of a proof test as well as a fatigue countermeasure. Also, that piston rod may be a heat treated alloy; heating it enough will allow it to anneal (crystaline structure changes to a weaker and more maleable form). True annealing requires very even slow baking to set temperature ramp and dwell formulas to avoid residual stresses. Heating via torch can both anneal and impart residual stresses; so you can end up with the worst of both worlds... a weaker annealed part with residual tensile surface stresses. Sorry for the blathering, I miss this kinda stuff; I love this kinda stuff. Now, someone ask me about brittle fracture or why we probably shouldn't ride our Buells in sub 15F weather. Hmmm, the thought just struck me, a piston rod just doesn't have to carry any significant (note I said "significant") tension. The only tension in the rod shaft (note I said "shaft") would be due to the piston's inertial forces during exhaust stroke which cannot be anywhere near the compressive load imparted by combustion. I'd gonculate those loads, but I left my slide rule at work. Besides, I bet Axtel knows! No worries about your rod polishing then eh? What about gun barrels? | ||
| Ralph |
Hey, what's the good of polishing the darn thing if I don't get to laugh about it? Now get back here and talk more. Were you being sarcastic I just learned something new... polishing imparts residual tensile stresses (very bad for fatigue) to certain metalic parts (I'm guessing more so for forged parts) and making fun of me or what? I can especially see how a forged part's inherent residual surface compressive stresses might be relieved by the force and heat of a polishing wheel/compound. What? There isn't enough heat to effect any stress in the material (not with me holding it in my bare hands!) and your first statement says the opposite about polishing adding/relieving stess. From everything I've ever seen the only way to relieve stress or soften a ferrous alloy is with heat. You can mechanically harden steel (or most other metals for that matter) by hammering (the hammer can be a glass pellet just as well as ball pein). Annealing, tempering or normalizing are all done with a specific heat. Mechanical hardening/work hardening is not something I've spent much time researching. It's just not a part of what I do. When I'm done with a forging however I heat cycle it to relieve stress and refine the chrystalin structure of my forging. So come clean, what chu' talkin' 'bout Blake? bighairyralph | ||
| Ralph |
Oh, sure, jump in and post while I'm typing (very slowly). The heat applied to the rods will be in the form of heated salts at 320 degrees f for one hour. That's below tempering temperature (this alloy would start tempering at 350 if hardend). That acts as a stress relief without any change in hardness. So, are you sayin' I screwed up my rods by polishing them? Okay, I'll bite. Brittle fracture. I thought the "big" danger of this was from heat treated steel having retained some austinite rather than fully forming martinsite before tempering. Then when the piece was chilled to a lower temperature than it had reached before tempering it would form untempered martinsite with all of it's brittle beauty. More of a problem with high alloy stainless steels than anything I deal with. Blather away, this is a knowledge vault and we're talkin' about my damn rods! bighairyralph | ||
| Blake |
Think "Titanic" (and all those WW2 packet ships we lost in the N. Atlantic)... coldddd water. Brittle fracture can occur in steels (of any temper) at cold temperatures due to their loss of ductility and the presense of residual tensile stresses, especially at welds where localized residual tensile stresses can reach 80% of tensile yield strength. You might be surprised at how hot the contact patch of your polishing wheel/rod gets. Similar to the difference in barrel temperatures inside versus outside? I agree though, probably not a major factor; I'm sure Mark will enlighten us on the main factor involved there. | ||
| Hans |
I want to have polished connecting rods. Apparently useless but so beautiful. Not impressed by any reason not to have them polished. Can`t wait to have a serious reason to build them out. Hans. | ||
| Al_Lighton |
Blake said "You might be surprised at how hot the contact patch of your polishing wheel/rod gets." Reminded me of something I witnessed the other night. I was polishing my stainless supertrapp muffler, and it was getting dark outside where I was working. The contact patch (OOOH NOO, not that word!!) between the muff and the wheel looked like a friggin aurora borealis! There's a boatload of static electricity charge generated between the wheel and the metal part, and the entire contact patch is one big spark. Made me wonder how much of the metal removal of polishing is due to the abrasion/friction and how much is miniature Electro-discharge machining! BHR, I bet your rod won't look so shiny and pretty after you put it in hot salts for an hour. Better stick with the metal cylinders, forget those clear plexiglass cylinders. :-) | ||
| Aaron |
Contact patch? Contact patch? You guys quit teasing me! Seriously, I know nothing of these heat treat or other stress reduction techniques, but back in my racing days, I had tremendous success at improving the durability of gearbox and rear axle parts when I shipped my stuff off for cryogenic treatment. Drivetrain failures were a real issue on that car until I started doing that ... twisted axles and broken r&p's and tranny input shaft/countergears costed me many races. AW | ||
| Blake |
What exactly did the cryo treatment entail? Sounds like a special type of tempering/quenching to improve the effective depth of the heat treatment. | ||
| Aaron |
Hell if I know ... all I heard was something about liquid nitrogen and -300 degrees. I was hoping you could tell me! All I know for sure is my failure rate on these parts dropped dramatically. Was it coincidence? Did I get fooled? AW | ||
| Ralph |
Cryo involves a sub-zero quench (-300 is what most use) and then a retempering of the object. Why? To convert any retained austenite to martinsite and then temper it. Al, they use to make electricity by rubbing fur (I think mostly cats, see, they are good for something). Then they came up with the idea of putting the fur on a wheel and spinning it. Sound familiar? This is of course about three hundred years ago. presense of residual tensile stresses, especially at welds where localized residual tensile stresses can reach 80% of tensile yield strength. Welds will leave a boundry area of hardend steel because of the material "self" quenching. That can be bypassed by either pre-heating to slow the cooling or by tempering after the weld. surprised at how hot the contact patch of your polishing wheel/rod gets. Sure, but tempering is a reaction to time at temperature. While the surface may be getting some heat, it's only present for a very short period of time before the mass of the material sucks it away and diminishs the effect. Hans, polishing the rods definatly has an effect. The important part of what I did was to eliminate the sprue marks and sharp machined edges. All areas that would build stress that could eventually lead to weakness or breakage. Did I go overboard for the intended usage? Yup, you bet! Just wait and see what happens if I can get the fly wheels back in time. bighairyralph | ||
| Al_Lighton |
Must have been a real bummer for the first cats that got strapped to that electricity generating wheel before figured out they could just use the fur...... | ||
| Hans |
BHR I have seen raw rods with characters printed on them and nuts and bolts to screw them together and they did not break. I want them clean and polished without ball peening or cooking in hot salts or whatever. It is imprented in my non technical brains that clean lines are best to have no stress building up on certain places. And rods are more than strong enough. Can I trust you that you will not ball peening them or cook them in fluids from hell ??? :-) Succes, Hans. | ||
| Ralph |
I made an ommision in my earlier post. Many of the items that cyro salesment want to sell you work on are heat treated. Typically the pieces are heat treated BEFORE having the machine work done. The machine work will always leave behind stesses. The cryo treatment will have a positive effect on items that fit this description. However, I believe it is not the cryo treatment itself that has the benificial effect in this case but simply the second step, the tempering/stress relief. In other words, most of what they accomplish you could do your self in the kitchen oven. Is that going to be true in all cases? Absolutly not. Is cryo treating cheap enough to not take the chance? Yup. Hans, I agree with you. A clean, smooth nicely formed machining will be stronger than a coarse, choppy thing with stuff sticking out all over it. How much stronger? Nah, won't even play with that. Dude, they're your rods, you can make them look however you want. Hey, what's wrong with salts from hell? They make flowers grow! Al, I didn't have time to take a picture before I shipped them out but they look even cooler now. A fantastic deep black imparted by the salts. Ron made me promise no engraving  bighairyralph | ||
| Blake |
Like I said, piston rod tension load is relatively low anyway. Simple f=ma right? Yeah, so now I gotta calculate the stinkin "a" and find out what the "m" is. I'll pass on that until I have some actual free time. But gee, ya simply need to figure the max rate of change of the rate of change in piston postion for max rpm... Hmmm using the equation of a circle with diameter of 3.8" (96.8mm)... r = 96.8mm/2 = 48.4mm angular velocity, w = 2p*RPM/60 rad/s q=2p*t*RPM/60 radians y=r*sinq dy/dq = r*cosq d2y/dq2 = -r*sinq Gotta figure in the motion of the rod relative to the crank/rod bearing... uh, too much for tonight, I'll leave the rest for Danny, wouldn't want to spoil his education workin such an easy calc problem.  Have at it guys, I'll finish up later if no one else gets it. Then, how much does the piston/wrist-pin/rings assembly weigh? Plus we'll need the weight of the rod itself too. Oh yeah, to be exact we'll need to know the pressure differential from piston face to crankcase during the intake stroke too. Phhhhbbt Ya right! Neglect it for now. I'd be neglecting friction too. sheesh... this ain't no 5 minute calculation is it. Back to heat treating thread... Great info about heat treatment of steel! Localized martensitic hardening aside, residual tensile stresses from welding are due to the tendency of the once molten weld metal to contract while cooling. The parent metal resists and ends up with residual compression in the area of the weld. The weld ends up with residual tension. The optimum machined part would be first be anealed, then machined, then quenched and tempered and cryo-quenched and tempered. Man, I learned some more cool stuff that I shoulda recalled from my Engineering Materials and Processes course. Wonder how long it'll take to forget it again?... Hope I don't. Knock on wood. Who's there? | ||
| Blake |
bhr: With all this rod polishing talk, did you mean to say that you made an "ommision" or "emmision"? heheheh | ||
| Ralph |
Blake, weight of which rod? They don't have the same weight. There's a monkey wrench for ya! I'd tell ya the weights of all that stuff but unfortunatly I didn't write any of it down. Weld contraction would explain some difficulties I've had in the past. Wrote it off to the heat collapsing the material. Shrinkage makes alot more sense. Thanks for the link. bighairyralph | ||
| Ralph |
Hey, that's not funny. That was a good link. Very basic and understandable. I'll print it out and give it to some friends of mine so they can understand what I'm talking about. They complain that I have to many words that end in "ite". Kinda like talking to an eskimo about snow. But I think I have more than forty words for describing steel. bighairyralph | ||
| Blake |
The heavier one of course. | ||
| Hans |
BHR, Salts from hell: Before the law made just having a gun here a capital crime I owned an Canadian Lee Enfield, a left over after WWII. Without bullet holder. Got at last a rusty one which I tried to restaurate. Could get no recipe for the nice original gun blue but for chemical blackening. Oh well, that would be close enough. Forgot the ingrediens but after the cooking the glass lining on the bottom of the cooking pan was GONE. (The holder became black.) Hans. | ||
| Rocketman |
In British bike history, rod polishing was done to remove the rough outer skin casting because this would greatly diminish the chance of fatigue cracks developing. In the old days, they use to immerse the polished rod in hot paraffin for some time, and after drying you would dust the surface with french chalk. If any cracks were present they would be indicated by the chalk adhering to the paraffin retained in the cracks. I read this in Tuning for Speed, the slide rule of motorcycling. I suppose, in its day, this book would be the equivalent of Denish's publications. Rocket in England | ||
| Axtell |
I also have a copy of that---good stuff--nothing really changes with time. |
