| Author | Message | ||
     Aaron |
Who's acting up? We're just telling BHR he's wrong  I don't know squat about motor design, but just looking at what others are doing successfully, these motors do seem to be "out there" on their strokes. Look at those Guzzi's ... they're oversquare pushrod motors and they run good. Look at a Chevy for that matter. Smokey always said he got the most power per c.i. on a 4" bore Chevy at 3-5/8 stroke. I like the powerband on the bikes, but I hate hitting the rev limiter when it's just getting good. I want another 1200rpm and 20hp, that'd make me happy. With no loss in torque of course! Hey, I'm not hard to please! I agree with the comment on the 130rwhp configuration. | ||
| Bigblock |
How about a dual injected, square or over, valespring-less(!) XL motor ? We have the technology. Might happen this year. Yes, I might know something you don't, but hey, I could be craZY | ||
| Ralph |
Blake, who said anything about efficiency? Did you buy your bike to get seventy miles to the gallon (good thing you crashed it before you found out the pistons were burned). Sure, it's a consideration but not the reason behind the burning desire to own a Buell-Beastie. At least I hope not. As far as emmisions go I don't believe you're going to do as well with an air cooled motor as with a water cooled motor. No matter how long you make the stroke. Hundred inches? Sure, can do. Check out your piston speed. Not my first choice for a long lived street performer. Lastly, where the hell are those improved rings you were going to design. Oh sure Aaron, use the Guzzi as a bench mark of performance. I'm not sure that's a good idea. I know less about motor design than you do (or Ron and Blake, probably Mikayla for that matter) but your not winning me over. You'll never get me to say anything against Smokey. 'Course that's cause he was right. But why bother with the Blast? A destroked S1 would make more power by simple virtue of having a large enough valve to be able to feed it. That's ignoring the bore/stroke. As far as manufacturing goes, why bother making an entirely new motor (basically the same as the other you already make) instead of simply manufacturing a different flywheel? Ron, you get my motor together (I forgot my darned rods, could you please ship 'em to me so I can clean 'em up?) and leave stirring up the engineers to me. Okay, so where are my answers? What would be the utility in setting the Blast up as a twin. Ron, you keep your monatary interest out of this. For real, what is the gain over what exists now? I really want to know. A "further refinement"? Bull. There is a point where refinement ends and it's time to start anew. I figure for Harley that was about twenty years ago. I guess part of this stems from my disappointment of the Blast motor from the very beginning. It's a heavy assed pathetic derivation of the Sportster, or if you want to be REAL, the flat head "K". I was expecting a single with performance, or at least the possibility of finding it. Doesn't Harley own or have interest in Rotax? Good lord, they used the same old piece of crap! Why do they even bother having engineers on the pay roll? I know that there is at least one engineer working for Harley/Buell that goes home at night and doodles the motor that I want. Instead Harley sends money to Germany for a car makers idea of a motorcycle engine. Great, just great. Lastly, lets keep this straight. While I have a strong interest in the future Buell motor I like what I got. I am firmly entrenched with my S3. I doubt I will ever let it go. I am a great believer in boring out the Sportster/Buell motor. Personally, I think everyone should do it. Hey, wait a minute, why haven't you? I know a guy who'll sell you cylinders! bighairyjustgettingstartedonmytiraderalph | ||
| Ralph |
Bigblock, missed that in the middle of my tirade. Hm, eliminating the valve springs is helpful but you still have a long way between the cams and the valves. That still leaves the bottom end. Take a look at it. Something about the fork and knife rods leaves a little something to improve on. Still to limited to be able to rev high enough to see the power Aarons wants. bighairydoneforthenightralph | ||
| Chuck |
Did ya'll know that decades ago, Harley actually produced a V4 engine. Supposedly production stopped abruptly because the public was, by this time, too addicted and enamored with the V twin . . . Never mind that the "new" engine was more powerful and efficient. Today, as in the past, Harley is simply supplying a demand and doing its best to give the people what they want. But remember -- We Buellers are more "pure-blooded" performance freaks -- and are still in the minority (so to speak) of Harley's customer base. Harley is doing a balancing act (of sorts) to satisfy the majority of its customers with "traditional" machinery - while improving designs to satisfy the emissions and performance requirements of the future. They are doing more R & D work than most are aware of . . . I for one don't care that our engines are antiquated -- I have ridden many sport bikes but have never been in love with one before my M2 . . .but if you don't like the bikes they build . . . then do like Erik did and build your own. | ||
| Aaron |
Ralph: add a cyl to the Blast engine and destroke a 1200 are synonymous in my book. What's the difference? Actually, I can think of one difference ... the Blast engine has no trap door for it's gearbox. That's one of the really neat things about these bikes, the ability to service the tranny easily. I hate to see that go away. So okay, you win, destroke a 1200. Like I said, I ain't no engine designer, it just seems like the engines out there that can do what I'd like my Buell to do are configured oversquare like this, and from what little I do understand about'em, it gives them more room for valves for a given displacement, or greater distance between the cylinder wall and the intake valve which also helps flow. Did you know an XR750 can twist more than 1000rpm higher and make as much or more horsepower than an XR1000? It's just a shorter stroke version of the same configuration. I'm biased about a sub-1000cc bike for obvious reasons. For street use, howsabout say a 4.25" bore and a 3.5" stroke. 111", 1825cc, give us a valvetrain that can spin 7500 to 8000. Throw in some kinda variable valve timing, too, so we can have a nice wide powerband. Think that'd work? Anyone know the dimensions on that new 1800cc V-twin Honda cruiser motor? I suspect it's a long stroke. AW | ||
| Aaron |
Hmm ... 4" bore x 4.4" stroke ... definitely cruiser stuff. | ||
| José_Quiñones |
My W.A.S.G. is that the next Buell engine specs (bore/stroke) will probably be based on the Blast! and the work that Tilley did on their Pro Thunder bike the last two years. Jay on ATC had a very good article about this in an old issue of the Weather Report HD didn't spend all that money on the Blast! engine to use it only on one model. The cam cover is shaped to accept four cams. If you move the airbox into the tank you have enough space for the second cylinder. And that rigid oil line between the pump and the filter screams "STICK THE OIL COOLER HERE" to me. This engine also has a piston cooling oil jet, according to the original Cycle World Review last year. I could find no reference to it in the P3 service manual. As long as they ditch the paper gaskets and go to o-rings, I'll be happy. | ||
| Ralph |
Chuck, I am unaware of any V4 production motor. I know for a fact they were working with, drum roll please....Porsche and developed a square four in the early '80s. Never saw any type of production. I know Harley/Buell engineers are busy. Show me what they've done. There is some filing cabinet in Milwaukee full of engines that could kick behind, but Harley just doesn't have the guts to use what they already own. Kinda like the 60 degree overhead cam with the reversable head that they never made. Funny, a couple years after development on that motor, Yamaha had a nearly identical motor, which did go into production. Aaron, the difference is they already have the cases/parts in production for a destroked 1200. Why spend millions designing/developing/tooling for a motor which will end up being virtually identical? I absolutly agree with you on the XR1000 vs XR 750. As well as the over square configuration and what would come from it. So, again, why bother with devoloping the Blast into a twin? Want a valve train to spin over seven grand, easy, put the cam on top! It's not a knock off, it's freakin' efficency! Jose, (darn little squiggly thingy, can't find the stupid button) why would you be happy with that? It's the SAME THING you have now! Piston cooling jet? Big whoopie. The only reason it exists is the oil has been so controlled the jet had to be added to supply the underside of the piston. Exactly what is done by the fly wheel in the motor you have now. Is it better, sure. Is it an improvement, sure. Could it have been done with the Sporty motor, sure. So why bother with designing a whole new motor the same as the old? My point is, instead of wasting resources doing the SAME THING, utilize them to devolop something new. A motor with real potential. Do not misunderstand me. I am Buells biggest fan. I love these damn things. What I don't like is the corporate mentality that insists on doing the safe thing, leaving them far behind ALL others in the market place. Look at what Aprila has done in a few very short years. The reason Erik Buell had to develop the first bikes outside of Harley was that mentality of live safe. I saw Harley buying Buell as a great thing. Buell would have the resources to make things happen and Harley would get some new blood and possibly create something great besides a cash cow. Now it seems like Harley has dragged a gifted creator down, paralyzing their life line to the future. bighairyralph | ||
| Jmartz |
The pushrod 45 degree motor can be made to perform quite handsomely if configured properly. Consider how the improvements of better fill, higher compression and lighter crank done to the Sportster motor resulted in our spirited Buell. The current valve train version (with those grose lifters) can tolerate 8,500 rpm with the proper springs. With a shallow chamber, decresed valve angle and straighter ports, together with larger bore and decresed stroke a motor could be constructed with pretty many of the same parts that are on the HD shelf. This motor would be capable of significant increses in HP& torque over anything presently on the market. The likely reason no one has attempted to build this concept is that the V twin pushrod market is dominated my BT's for custom applications. Patrick and others could easily produce heads like I mention and S & S already makes the flywheels, cases and other parts. The problem is that the goal of any business venture is to make money and to do so that broader market needs to be targeted and that is not the "american sport bike". | ||
| José_Quiñones |
Follow this link to the past.... | ||
| Mikej |
Didn't H-D make a pancake-style engine back in the 1940's, but then never hit much production due to WWII? Or maybe it was more of a Moto-Guzzi style "V"? | ||
| Blake |
bhr: I didn't mean to imply to get 100" solely by stroking. Just a normal axtell 100" evo would be fine. Efficiency is not my priority either, but it is a positive feature of the long/slow HD engines and it's interesting versus the inferior performance of the so-called "state-of-the-art" high tech machines today; kinda makes you say "hmmmm." I guess that's why Duc has to mount he EPA canisters on all their new S4 engined machines... too much spewage out the exhaust?? | ||
| Ralph |
Mikej, Harley made an opposed twin during the war. Basically a beemer copy with some changes, but not much. I could swear I've seen a Harley V mounted the same as a Guzzi but if I did for real it was an early one. Blake, didn't figure you were going to stroke all the way to 100" (oh god, please don't take that out of context). With stock cases you can go to 3 13/16, S&S cases will take you to a 4" bore. That'd be 88 inches and I just don't know how much from the four inch bore. But now your stepping on yourself "Long stroke, low RPM is mucho more efficient than short stroke high RPM no?". By increasing the bore while leaving the stroke alone aren't you changing the bore/stroke ratio? Turning the engine into a comparitivly shorter stroke engine with different characteristics? Going with the Axtell big bore is the way to go because the darn engine is already a stroker. Jmartz, I can make a brick fly. All it takes is enough motor. That doesn't mean one should pursue flying bricks past the point of having a laugh. Show me a 45 pushrod twin that'll turn 8500 rpm for more than the time it takes to get down the quarter mile and get rebuilt before the next run. I'm sorry, there is just to much valve train mass to deal with. It can be done, and is, but not on the street. The way to deal with that problem is simple, eliminate the mass. Put the cams over the valves. Thanks for agreeing with my thought that a destroked version of the present motor would perform well. Of course a bored version of the the present motor would kick it's lilly liverd tuchas. So, no one will say anything positive about the Blast being made into a twin. Fine, but you are all no fun. Don't mean to be a butt-head, just feel like butting heads. bighairyralph | ||
| Jmartz |
My point was to state that one could get a more competitive motor form our current design. I agree that this 1957 motor is less than ideal and that DOHC is the way to go when designing an engine from the ground up. I disagree with you that it would lack durability. The forces generated at a given rpm are directly proportional to the weight of the reciprocating masses and the stroke. The same level of internal forces that we have in our Buells at 6800 (its redline) could be acheived at higher rpm with a shorter stroke. Tilley has a 3.6 stroke x 3.75 piston diameter motor in stock cases making 120 HP at 7800 rpm. Just imagine it in S & S cases with 4 inch bore, 3.5 stroke and light rods. | ||
| Chuck |
I must agree with BHR . . . the valve train is the limiting factor. To quote a friend, "Anything much over 7 grand and you will involuntarily become a Harley "parts distributor""  | ||
| Jmartz |
XR-750's have a 9000 rpm redline and have essentially the same valve train as a Buell. | ||
| Axtell |
Jmartz--have to disagree on durability---can't just use the difference in mass---have to add the added stress and deflections of the higher power output. The xr is at the end of its development (probably 10 years ago). It is more efficient than a xl but not what you would want to look at when step-stoning to a new and higher level of engine development Aaron--you should bring up TOC :-) | ||
| Ralph |
Jmartz, define competitive. I don't agree. Buells have had a racing class made for them. They don't win. Ducati 748's win. A motorcycle with it's own racing class that it can't place in, much less win, is not competitive. This motor does not date to '57, keep going back. The over head valve Sportster motor was lifted from the flat head "K". Not that I have a problem with that, just being a butt. Those XR-750's blow up if they go another lap. You're right, but it still won't go on the street. J, what I'm talking about is a new motor. You are absolutly right in that this motor can perform even better. But I just don't think better enough. Maybe, it's time for another design. A guy can't even say more modern motor, all the aspects of "modern" motors have been around longer than Old Weird Bob. I'm not saying to ditch this motor, I'm in love with it. There is enough room in Buell to have two, okay, three motors isn't there? The more I learn about this motor the more I see it's limitations. On one hand that makes it more interesting. On the other hand it makes me wish there were other choices. Without going to another countries product. Speaking of valve trains, why isn't anybody making carbon fiber push rods for the valves? It wouldn't be that big a deal to cut some rod and glue on steel tips. | ||
| Aaron |
TOC? What the hell do we need a Table of Contents for? Just kidding ... lemmee see ... What's constraining the system? Isn't that where we should put out efforts? How was that? A start? Let me step in a little deeper. The lack of rpm is constraining the horsepower, so what's constraining the rpm? - the inability to get a good cylinder fill? - the inability to control the valvetrain? - the lack of strength of the lower end? - all of the above? Take it from there, sir. Back to uninformed opinion mode (hey, it's more fun that applying thought methodologies!). I don't buy this notion that a pushrod valvetrain is limited to 6800rpm. I sound like a broken record, but look at the Guzzi ... a 7800rpm production pushrod motor. In race form, they're twisting 9200rpm. Obviously that motor has a valvetrain that can do it and heads that can breathe. That's a big advantage for them, and disadvantage for me, uh, I mean us. Hmm, look at that, it's oversquare! BHR: don't forget that the valve spring has considerable mechanical advantage on the pushrod and tappet. The constraint might be on the valve side of the rocker. AW | ||
| Ralph |
I'm guessing we stopped talking about the Blast motor awhile ago. I'd prefer not to talk about anything in race form. To many variables, like what kind of race. Let's keep this to streetable, relitivly low maintainance type of stuff. Solid lifters a-okay, pneumatic valve train - no way in hell. Aaron, I didn't know Guzzi was revving that high in stock form. Guess I gotta look now. Sure, the valve spring is a huge part of the equation, but remember, not only does it have to pull the valve back up, but it also has to push the rod back down. It stands to reason that a lighter rod would give the spring less work, hence lighter springs that are still capable of handling the valves without having to deal with the mass of the rod. Less heat, less compression because of a thinner spring, blah blah. But hey, since I'm talking out my butt, avoid the mass of the entire deal and put the cams on top. Lovely, eh? Okay, sorry, I'll keep on track now. What is the difference in design between our push rod system and Guzzi's? Don't they run the cam between the cylinders? That would give them a very short pushrod with low mass. So lets talk more about carbon fiber push rods. Ron, you told me once why it wouldn't work well but I forgot. I must not have liked your reason. 'Course I never like your reason for why my ideas don't work. What type of crank pin/pisoton con rod is Guzzi running? Silly knife and fork like ours? What the heck could we do about that? bighairyralph | ||
| Aaron |
Ralph: of course I understand the point of lighter pushrods, I'm just saying that gram for gram, taking mass out of the valve side of the rocker arm will have a bigger return. 1.625 times as much return would be my wild assed guess. Ti valves are a good thing, just pricey as hell. Course CF pushrods aren't free, either. CF valves, that's the ticket! I don't know much about the Guzzi motor, but I'd be real surprised if it's a common crankpin. Look at the pictures on this page ... it would appear that yes, there's a single cam in the valley and the pushrods are maybe somewhat shorter, but not a lot. Seems like they could be with that configuration. That arrangement would sure simplify things versus what we have now. Fortunately for me, the Guzzi boys are locked into shaft drive. That's our advantage. AW | ||
| Jmartz |
Well, I guess we need a new motor. The hell with the old design. HD give us a 100 rwhp bike with an 8000 redline for 2001 or I'm getting a Ducati 998, and that's final. I've had to postpone my Daytona trip till Tuesday the 6th due to rain. Hope the old "dirty bird" doesn't throw a rod at the 7000 rpm I make it visit routinely. Jose | ||
| Ralph |
Actually Jose, while I'm looking forward to a new motor for Buells I'm keeping my S3 and maybe the S1 as well. As much as you may think I'm maligning the motor I really do appreciate them and kinda have a soft spot for them. Check back with me in ten years, I'll bet you I still have the old clankity S3. Aaron, thanks for the link. I can't really tell from the picture, but it doesn't "look" like a common crank pin. I guess I've been overestimating the weight of the push rods and ignoring the altered leverage of the rocker. Man it sucks messing with engineers. But lighter rods would still help  . As far as cost goes, I was kinda figuring on playing around with some CF rod and making a set. That would be project....#187. Carbon fiber valves, hm.....lets mark that down as #7832. By the way, you know I have #8 marked down for some foot peg detents. Now if only I could get a guy to send me a lousy ball bearing and spring. bighairyralph | ||
| Jmartz |
Axtell: I though those distortions at high rpm were due to forces induced by the weight of the reciprocating masses. Are you telling me that if I used Titanuim rods, tapered pins and short flat pistons and subsequently dropped 1lb or so from the piston/rod assembly, the flywheels would still experience the "spread" they are known for when the internal speed reaches 8000 rpm. With forces increasing by the square of the angular speed it would seem reasonable to expect critical levels to be reached at higher rpm when using lighter parts. Jose | ||
| Axtell |
The weight of the parts are a contributor to deflection but not the sole cause. The spread you talk about is exactly that, the flywheels spreading apart 180 degrees from the crankpin. Think about it--does that sound like it could be caused by the reciprocating parts being too heavy? If that was the case I think you would find "pinch" The flywheels spread normally because of high cylinder pressure at DTC when the rod has no angularity. Lighting up reciprocating parts is good. Doing this to make the flywheels appear to be more massive is good. This is why I am not fond of light flywheels.(don't get me started) we cannot assume that the engine is ok now and lighting up parts will allow us to rev higher SAFELY. I think that no matter how light we can make the pistons it won't make the side shafts of the crank any larger in diameter :-) | ||
| Jmartz |
Axt: I beleive what you are saying is that the lower end in its present design is not suited for much more than 7000 no matter what we do. The crank pin is too small to accomodate the rollers. Have you seen the new motor from mid-USA? It uses a plain beaing car like crank with a much larger journal. The side shafts are the same though. What really worries me is that the rods being side by side are no longer under the center of the pistons. | ||
| Bigblock |
if the valvespring-less set up actually happens, that should help, as far as the bottom, some guy ( I can't remember who) was making a Harley case w/ a offset bore so ya run 2 male rods(!) aand big crank bearings like the XR750, what the hell, run rivera 4 valvers, you elimanate the excessive valvespring pressure caused by 2 on 1 w/ the valvespring elimanater, run dual carbs or injection, and you'll really kick some butt(as well as break the bank!)hopefully, a couple months will tell if the valvespringless setup is gonna fly, hope to test dual injection soon.(?) | ||
| Jasonl |
From this conversation I feel like I did when I was a little kid working on cars with my Dad and his friends. I'd just stay out the way and soak it all up. It was a great day when I finally understood ~some~ of what they were saying. | ||
| Airborne |
Great conversation on bore/stroke, valve train etc. Here is some food for thought for more power and engine design. I heard on speedvision while watching the season opener for F1 racing that one of the car companies was working on a "ELECTRO-MAGNETIC ACTUATED VALVE SYSTEM". I was half asleep when I heard that and didn't catch which company was designing it but look for it in about a year in F1 Racing on either a McLaren/Mercedes or Ferrari. Consider the advantage it could give the Buell motor. Less engine heat, power gains, higher revs. On another note: I saw a picture of a Harley motor somebody had modified to a OHC design using a pulley system something like a Ducatti. And then again. Why... doesn't Harley release the 60 degree V-twin, FI (twin throttle body), OHC, water cooled 130HP motor used in the VR1000 for the consumer market. I know somebody will say something about being able to buy one but last I heard was you had to be a licensed racer and afford the $50,000.00 price tag. |
