| Author | Message | ||
     M1combat |
I suppose the problem with a supercharger is that we would need some machine work? Anyone look in this direction yet? | ||
| Djkaplan |
"So much HP requires so much cooling. If a 130 HP naturally aspirated Buell engine can operate well via air cooling, there is no reason that a 130 HP turbocharged Buell engine cannot do the same." I don't think a 130hp Buell would cool itself well anywhere but on a racetrack. In the real world, street motorcycles don't get a cool down lap and get stuck in stop and go traffic. I'm not saying it's not feasible, but I can't see any engineer thinking that a turbo Buell would be prudent for production. | ||
| M1combat |
It seems to ME that we have more cooling than what's really "needed"... My fan rarely comes on unless I'm on a longer trip and having fun. Even then, it only comes on when I shut the bike off. It's only ever turned on while riding once and that was in Tucson at about 116 degrees in stop/go traffic... Also... We could theoretically get a more powerful fan and a temp sensor that'll turn it on at a little lower temp. | ||
| Roc |
If a tube frame Buell or HD can survive a turbo than an XB should do just fine, much more heat management built in. Also, the oil plumbing is already present in a logical place to mount a turbo. If you look at an XB with an eye to adding a turbo you will be happily suprised. | ||
| Martin |
Also, the oil plumbing is already present in a logical place to mount a turbo Could you be a little more specific, please? | ||
| Jens |
Hi, I builded TF and XB Turbos, a supercharged XB as well. If you really like to boost the XB engine up to HP with injection and drycharging you first of all have to get a head on the engine fuel and ignition management. I drove personalty more than 5.000 km with charged XB´s, they are all running, they all stay alive. Nice to cruise with. But in the moment when you rise up the Boost you are trapped by the ECM. We are working on the free programmable ECM solution, meanwhile these projects are "on ice". On the day we have full control over the engine we go further with these project. Using wetcharging with a carb is easy done but thats an unacceptebale step backwards I think. Placing the turbo on the XB is not so easy as it looks. If you not like to use a scavenger oilpump you are very limited in placing the turbo. For the cooling, the XB is good in accepting an Intercooler under the Tankcover. Happy plumbing (-: Jens (Message edited by Jens on July 20, 2005) | ||
| M1combat |
"We are working on the free programmable ECM solution," Jens... Have you looked into using a Mega-Squirt and an aftermarket ignition? | ||
| Jens |
M1combat, yes I have thinkin about the MS too. For now we have a Perfectpower ECM from SA here but I dont find the time to develop the Maps from the nothing. So at moment we run on the street and track a new piggyback solution what makes the inj and ign side full adjustable. Looks good for now and is market ready, but it have no boostoperated Turbo options. But for our 1170 and 1430cc engines it looks like it will be solution. But I agree when you think in the end we will have the ECM replacement. MS in combination with a Dyna or HI4 could be a solution too. When you have a start on the MS let us talk. Jens | ||
| Johnk3 |
I think craigster had a fully operational MS module on his bike. You should ping him, he seems to really know his s h i t | ||
| Blake |
DJ, I'm not an Engineer, but I stayed at a Holiday Inn Express. I'm thinking of taking the test to be an Engineer though. Consider that the only time you need to cool 130 HP worth of performance is when you are running the engine that hard. At idle or cruising down the road or when sitting in traffic a 130 HP turbo-charged engine won't create any more heat than a stock Buell engine. Blake (BSME)  | ||
| Scbueller |
So how much boost can I run with the stock ECM? What is the point where the stock fuel injection system is maxed out 1,2,8psi? Cant I put on a fuel pressure regulator , possibly a fuel pump if needed. Why wont the stock system adjust accordingly does it work too slow? hey combat where do live and your fan isn't on that much my fan is on every time I ride. The dealer said if I wanted my bike to run cooler not to ride it in the phoenix summer heat, 119 yesterday | ||
| Scbueller |
Just for the imagination someone told me he saw a smog pump that was all polished on a bike used as a supercharger with no fuel modifications. how much power would one of these make? Not that it would look good or anything on an xb but a TURBO yesss | ||
| Blake |
How much boost will a stock ECM accommodate? None. At WOT the DDFI system runs in open loop. No way for it to know that you are forcing a lot more air into it. Same as any EFI. | ||
| Opto |
Is it true that an air-cooled engine radiates heat in proportion to the square of the temp, and that's why an air-cooled engine can run hot, but never fails from overtemp? (unless there is an ignition/fuel fault). I've never managed to overheat an air-cooled motor yet, not even a Briggs and Stratton, a '59 VW, a 125cc 26HP 2-stroke, a CB400/4, a CZ250 or an Indian 741, and a heap of others. And you can't overheat a steam engine because it's "steam-cooled". | ||
| Blake |
Even better, net radiated energy increases proportionally with the fourth power of the radiating body's temperature (T4) relative to the surrounding environment, and remember to use absolute temperature scale (Rankine or Kelvin). | ||
| Sweatmark |
Blake, are you modeling the engine mass as theoretical black body? Don't forget significance of convective heat transfer, unless Reynolds number of airflow through cylinder vanes suggests modification of boundary layer. But seriously, the turbo thing can obviously be done, with appropriate investment of development time & money. I bought a fairly simple supercharging kit for a former car, which used adjustable fuel pressure regulator for (crude) A/F ratio control boost to atmospheric... the AFPR system worked better than expected for low boost application. The car's DME included knock sensors for spark retard, and the blower kit ran rich under boost... but it still worked. Sooner or later an engine mod will tempt, since the Buell is my hot-rod fun bike; I wouldn't consider tinkering with my trusty Beemer, though! Modding the XB's bore & stroke would be 1st choice, but (turbo)supercharging could be fun "edgy" alternative, even if not as practical. Let's keep this idea alive! Mark (also BSME)... trying not to BSyou | ||
| M1combat |
"Blake, are you modeling the engine mass as theoretical black body?" I think he would be when talking about radiated energy as opposed to energy released in the visible spectrum. I could be wrong . | ||
| Blake |
Hey Mark, Good to see another BSME on BadWeB. In answer to your comment wrt convection... You are correct of course, but we were not addressing convection, just the comment above by Opto concerning physics of radiative heat transfer. As to real world emissivity versus a theoretical black body (perfect emitter/absorber), emissivity has no effect on the 4th power relationship wrt temperature. Radiation of heat energy increases with temperature to the fourth no matter the emissivity. The emissivity factor applies to the amount of heat radiated, but does not change the fourth power relationship; it simply factors the emitted heat energy the same at all temperatures. Here's the math... Q=heat flux (watts per sq meter per second) e=emissivity A=effective radiative surface area Th=absolute temperature of hot surface Tc=asolute temperature of cold surface or ambient surroundings And to clarify, yes, an emissivity factor/constant can change some over large temperature ranges. And no, the real world is rarely so simplistic that the above equation is all that is needed. But the above illustrates the basic physics of radiative heat transfer. Of course even for free convection cooling the heat transfer also increases with increasing temperature of the hot surface, not proportionally to the fourth power of temperature, but it does increase. Would be interesting to know how much the Buell engines depend on radiative heat shedding versus convective. Given the XB engine is fairly well enclosed and relies on a fan, I would assume most cooling depends on convection. That might not have been the case with the tube framers though. | ||
| Djkaplan |
"Even better, net radiated energy increases proportionally with the fourth power of the radiating body's temperature T4 relative to the surrounding environment..." The Stefan-Boltzmann constant that's used in this equation is very small; radiation heat transfer doesn't become significant until you encounter very high temperatures. We can parry back and forth for days over this (and, indeed, we have), but I'm still going to stand by my original assertion: I think air-cooling would make it prohibitive to do turbocharging for production, especially for a Sportster based engine. There is no way with the engine's current architecture that it could pass the heat soak and durability tests for production. | ||
| M1combat |
Not even with the fan (that's a stock part of the cooling system)? I'd maybe agree that it may not pass the durability testing portion, but I think it would do fine wrt the heat soak portion. JMO of course . | ||
| Djkaplan |
"Is it true that an air-cooled engine radiates heat in proportion to the square of the temp, and that's why an air-cooled engine can run hot, but never fails from overtemp? (unless there is an ignition/fuel fault)." You can run an air-cooled engine hot enough to cause failure. | ||
| Djkaplan |
Not even with the fan (that's a stock part of the cooling system)? If you did a full power (130hp?) run and stopped and parked the bike, I think heat soak would be a significant problem, even with the fan. But, until someone does some physical testing, it's JMO, too. | ||
| M1combat |
I think the only way I would do that to my bike is if something else blew up on the run and I didn't have a choice... aside from that it would always get at least some cool down. Keep in mind that even if you DO run a full throttle run for whatever length you like the bike will keep the fan going until the rear head is as cooled off as it likes it to be. I assumed by "heat soak" you meant sitting in a four sided tin area in the AZ heat idling for an extended period. | ||
| Blake |
Yes the constant is small. What is your point? That something needs to be hot to radiate heat energy? It still increases with temperature to the fourth. That's all I'm saying about it. I don't contend that the XB relies at all on radiative heat shedding to stay cool. Pretty sure in fact that it doesn't. As to turbocharging, I am confident that if Buell decided to offer a turbocharged model they would darn sure make it right. How on earth do you figure that a 160 RWHP sportbike ever survives heat soak after shutting down, especially considering that its primary coolant ceases to circulate? Note that upon shutdown, the XB's cooling system continues to run and to circulate coolant as needed. As to heat soak of sitting and idling, as explained before, there is no additional heat created at idle, so that would be a non-issue. Or are you thinking the turbo plumbing on the exhaust tract side might be problematic? Proper design and integration of the turbo keeps exhaust heat away from the engine. | ||
| Djkaplan |
How on earth do you figure that a 160 RWHP sportbike ever survives heat soak after shutting down, especially considering that its primary coolant ceases to circulate? The exhaust seats and valves (the parts that get the hottest) on a 160hp sportbike never get to the temperatures you'd encounter on an air-cooled Sportster engine with a significant increase in power over stock. It's the rear exhaust valve and seat that is the crux of the whole problem. Anyway, if Harley produces a turbocharged, air-cooled, Sportster based motorcycle, I will say I was wrong. Until then, I stand by my assertion. | ||
| M1combat |
So what you're saying is that we may need a valve seat that's made of a material that will quickly transfer more of it's heat to the head (that we can directly cool even after shutdown) than what we currently have... Sounds doable to ME... Again , just MO. | ||
| Blake |
"The exhaust seats and valves (the parts that get the hottest) on a 160hp sportbike never get to the temperatures you'd encounter on an air-cooled Sportster engine with a significant increase in power over stock." I'd like to take that on faith, but I don't buy it. How do you arrive at that conclusion? Back about thirty years ago valves and valve seats were susceptible to being "burnt" by the wicked high temperatures of high performance high compression engines. Pretty sure that was happening while the engine was running, not after shutdown. Not so these days. Metal alloys have made leaps and bounds in their durability and strength in hostile high temperature environments. Why didn't the air-cooled turbo Porches' valves/seats burn up? Pretty sure they didn't have a cooling system that continued to operate after shutdown. Also, the exhaust valves and seats are in the same combustion chamber as the aluminum piston. My thinking is that if the piston doesn't melt upon shutdown, it is highly doubtful that the steel valve will. Pretty sure the valve seat will immediately cool down as it is in intimate contact with the aluminum head that is being vigorously cooled by the forced air cooling system. It is also very difficult to imagine any realistic scenario whereby a street bike would be WOT cranking out 130 RWHP at ~7,000 rpm for an extended amount of time then immediately shut down with no significant warming down interval. DJ, I think yer just bein stubborn. Of course I know nuttin about that.  ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif) | ||
| Djkaplan |
"Why didn't the air-cooled turbo Porches' valves/seats burn up? Pretty sure they didn't have a cooling system that continued to operate after shutdown." Porsche used an engine driven fan (engaged all the time) enclosed in an elaborate cooling shroud to force air directly to cylinders and heads that had cooling fins designed strictly for the application. Porsche also used a huge oil supply (twice as much for an engine half the size of a typical American water-cooled V8) plus a large oil-cooler that had a significant effect on cooling the engine during operation. That's how they kept temperatures in check on their engine. Without a system as efficient as this to shed heat away from critical areas in the engine, temperatures would be have to be higher. You don't agree with this? I don't think I'm being stubborn. I think I'm just following conventional wisdom on the subject. I'm certainly not clever enough to come up with most of this stuff on my own. | ||
| Firemanjim |
DJ.All of those rear engined cars,VW,Corvair,Porsche, all had to have engine driven fans and serious air ducting to get enough air to cool them regardless of turbocharging as they were a bit out of the airstream stuck as they were on the backside of the vehicle.Typical american V-8 of the time had 5-6 quart capacity of oil,what was the Porsches? | ||
| Sarodude |
The couple of 70's NON turbo Porsche's I remember working on had like a freakin' ridiculous oil capacity. Maybe I'm smokin' crack - but I remember something in the 10 - 12 quart range. It doesn't sound right - but that's what I remember. -Saro |
