| Author | Message | ||
     Jerome Chappellaz (Jerome) |
Henrik : I think it's best to install it as on OEM injected models, i.e. a few inches from the rear head exhaust port. Not only because it gets quickly to the required 600°F for starting to have correct readings, but also because the rear cylinder is supposed to be the one running leaner (as it gets warmer than the front cylinder). And it is definitely better and safer to tune your carb based on the leanest cylinder, instead on an average of both cylinders... I suppose the Buell engineers decided to put the O2 sensors at this specific place on the injected models, for that same specific reason. | ||
| Doug Lofgren (Moperfserv) |
Howdy, My name is Doug Lofgren and I was involved with the development of Mike Roland's S2. I found BB and find some of the discussion interesting. Since it's Winter up here in the Northland I'll be spending some time on the 'net. I'd enjoy taking part in some of these dialoques, or answer any questions. | ||
| Dave Tripp (Tripper) |
Howdy Doug, and welcome. I think most of the people here have absorbed your fine site where you detailed the building of the twin-carbed beast. Nice work. I was interested to see that he returned the bike to a single carb for regular riding. Did I read it right that this resulted in ~25 HP reduction? | ||
| Stuart Mungomery (Wet4uracing) |
doug, I was very impressed with your exhausting testing,and was hoping you may have had some drawings of your manifolds with :lengths,diameters,bend radius.etc. I toyed with the idea of two flatslides (off a 4 cyclinder + 2 spare)out the ignition side thru a machined manifold(separate tracks).But I could not find anyone with information on the above specifications.You sound like THE MAN.If you have the time or inclination I would be very interested in hearing your thoughts.I road race my S1 WHITE LIGHTNING (82 HP) against other S1 Buells 105 hp + (unreliable)all I can do is pray for rain. thanks, stu. | ||
| Jasonl (Jasonl) |
Doug - good to see you here. We've all been crawling over your page to find out what's going on with twin carbs. Too bad the Holley carb looks so poor right now (2 throats, single runner manifold). | ||
| Doug Lofgren (Moperfserv) |
Re: Dave Tripps comments. Roland took the heads off of the S2 to build another engine to go Pro-Thunder racing. That was for the Brainerd National. Not enough time!! The result was, in fact, approximately 25HP loss. Same cams, same pistons, vastly improved stock heads (instead of the billet ones)S&S 'G' carb. Re: Stu's question. Although the S&S carbs are a rather elemental instrument, they are tunable. (Can't quite make them hum the Star Spangled Banner yet?) We thought about 45mm Mikunis or Kiehins but the taper of the manifold was already dialed into the 'tune-up', so we decided to leave it just the way it was. Any given change could lose a bag of power. The point is; it all has to be tuned. The more power you get, the easier it is to upset the combination. I've noticed quite a few comments about 'xxHp without any dyno work'. Every time we made a change it put us 'in the ditch'. If you guys would do your homework (read; dynowork) everyone would kick our butts. (It ain't 'rocket science') (no reference to Sean) I've just revealed 'the secret' to HP !! | ||
| Drew K (Cyclonem2drew) |
I'm planning to add a slip-on pipe to my '00 M2...I'm leaning towards the Daytona Boss. I was told that, at the same time I add the muffler, I have to also have to rejet my carb (buy a Dynaslide Kit) and a higher flow air intake, such as the Force Sidewinder or the Buell Race Filter. Without these other mods, I'm told, the M2 will not work well at all with the new Boss pipe. Is this true? At this point, I'm more interested in a lot more noise and a little more power...I plan to do the other mods later. What do you all think? | ||
| Jerome Chappellaz (Jerome) |
Drew : IMHO, you should rejet your carb. One word about my own experience with a SuperTrapp, everything else being stock : my bike was running WAY too lean except at wide open throttle (I could see that on my air/fuel ratio gauge). When I changed the original breadbox and replaced it with the Force, it became WAY too rich... Carburetion is much affected by the free-flowing of gases in the exhaust and in the intake, and it is not straightforward to guess what the effect will be, except if you have a tool like an air/fuel ratio gauge or a dynometer nearby. | ||
| Henrik (Henrik) |
Jerome: thanks for the sensor position info. something to play with over the winter. Lots of good info about air/fuel ration gauges on Autometer's website btw. Their sensor kit is expensive though. You just used a regular Bosh sensor, right? Henrik | ||
| Jerome Chappellaz (Jerome) |
Henrik : I used a NGK sensor for an Opel automotive. Get the cheapest one with single wire and the right thread, from any automotive part supplier, no need to put a lot of bucks in this. They all have fraction of a second reaction time and 0-1 volt output. | ||
| Stuart Mungomery (Wet4uracing) |
Doug, I was actually hoping for a starting point,or failing that,specifications to re-create your system.Could you not mount the carbies side by side?Do you have a manifold kit available for sale?I now understand why I cant get the answers to my questions.Is it possible to calculate the length,diameter and taper for a given carby bore size and then to manipulate these figures to produce a maximum torque and horsepower peak at a given rev range?Then it would be a matter of fine tuning on a dyno to try and duplicate the theroretical results.Were both manifolds the same length and if not why? Sorry to ask so many questions but I would really like to build a similar/same system. stu. | ||
| Jasonl (Jasonl) |
Doug - the secret to hp is dyno work then? I can understand that. I'm sure you understand that not everyone has access to dyno time as easily as some others. I'm take your word for it though. Just the same we appreciate you blazing a path for the rest of us to use as a guide. Also, we discussed here the option of using the Holley carb on the EVO motors. In your experience..do you think a manifold could be made to seperate the 2 venturis on the Holley to make it a dual carb setup with one carb body? I'm interested to hear what you think on this since the Holley has 2 "throats" but will bolt up to the single manifold. | ||
| Doug Lofgren (Moperfserv) |
Mounting the carb side-by-side would limit the turn radius of the manifolds. That would cost air-flow. That might be why the new NHRA Pro-Stock rules allows up to 60 degrees of cylinder angle. I can imagine Byron Hines requested that. Since the heads are billet, and little chance in sight that Shumaker can get his act together to make more, we have to have castings made. I just moved my shop, and Roland works out of his basement. Neither of us has $20,000 for the casting boxes and the rest of the stuff to do that. S&S isn't interested. Buell isn't in a position to do that either. Maybe Ron Dickey, who's on this list, and an old friend of Roland's, should give him a call. You can calculate all of the dimensions, some programs are better than others,(We used Dynomation and correlated the results with our dyno testing.) It's mighty compelling to think you can do the greater part of you development on paper, but we've found that the calculations (simulation programs, in this case) are rough estimates. I don't see a practical way to modify the stock parts to do this. Australians probably will. The inlets were the same length. | ||
| Doug Lofgren (Moperfserv) |
H-D has already done the dual choke/separate manifold thing with the Twin-Cam injected engine (and Evo before that) the inlet length isn't long enough to really do the job, but they do get equal fuel distribution at part loads, which is a big problem with 'Y' manifold engines. Also the injected engine is restricted by the thottle size. H-D sized it to maximize it at about 75-80 HP. Just to get the record straight, I don't know spit about Harleys. I do a lot of jetting on them, so I have some experience of that. But, virtually no mechanical knowledge. However, that is one of the reasons we went the way we did. H-D has a culture that implies that 'it's all been done already' and that isn't the case. The XR750 is the Harley that shows that this works, and it shows it well. | ||
| Doug Lofgren (Moperfserv) |
H-D has already done the dual choke/separate manifold thing with the Twin-Cam injected engine (and Evo before that) the inlet length isn't long enough to really do the job, but they do get equal fuel distribution at part loads, which is a big problem with 'Y' manifold engines. Also the injected engine is restricted by the thottle size. H-D sized it to maximize it at about 75-80 HP. Just to get the record straight, I don't know spit about Harleys. I do a lot of jetting on them, so I have some experience of that. But, virtually no mechanical knowledge. However, that is one of the reasons we went the way we did. H-D has a culture that implies that 'it's all been done already' and that isn't the case. The XR750 is the Harley that shows that this works, and it shows it well. | ||
| N. Garretson - Sportster List Race Team BBS Admin. (Lsr_Bbs) |
The intake tract on the 45 degree twin is one of the biggest hindrances to makeing power (other than the pushrod valve trains inability to spin at high rpm reliably and in a cost-efficient manner). The narrow angle doesn't allow for large sized, separate intake tracts...you either have one large one that's shared, or two too small ones. Then there's the side draft intake style which is getting it's intake from some of the 'dirtiest' air on a motorcycle. Now, if you had a large intake plenum (say 8-10 ltr.) feeding through downdraft carbs...oh, wait. That'd be too JPOS, and we couldn't have that now could we?  Neil Garretson X0.5 | ||
| Bryan T Nill (Loki) |
Doug, is Shumaker the one who did the mirror image head that had a carb hanging on both sides of the bike? Thr pics I saw looked way wicked. Neil, I thought it had been done in a way already. That is using a downdraft Del'Orto set-up on a custom split manifold. Not on B but on a big twin sometime back. Can you imagine sitting there and looking at a carb stack beside your tank. It would be trick,but totally in the way of things more important. Like steering..... loki | ||
| Doug Lofgren (Moperfserv) |
Shumaker made the heads. The front cyl. port is a mirror image of the other. Ducati's injected bikes have the inlets under the tank. Above 5000RPM it sounds like someone's beating on the tank with a ball-pean hammer. | ||
| James BuellElbow Witt (Jim_Witt) |
N. Garretson wrote: The intake tract on the 45 degree twin is one of the biggest hindrances to makeing power ... ----- If that's the case and it's not practical to design, manufacture and cast new components, then a turbocharger sounds like the most practical option to achieve maximum horsepower/torque to me. Cheers, -JW:>) | ||
| N. Garretson - Sportster List Race Team BBS Admin. (Lsr_Bbs) |
Loki, not quite what I'm talking about. I'm talking a large (like 10+ litre - as in 5 x 2ltr. coke bottles, a lot of volume) airbox that feeds 2 carbs...how any current sportbike is. Would never work on a current buell without MAJOR reworking of the frame, isolator/mounting system and bodywork/fuel tank, suspension and exhaust....would never work on a H-D w/o even more work. JW, yep. 45 twins have been pretty much tapped out from a reliability + cost/hp ratio (yes, with enough $$$ you can make big hp or go faster, but I'm talking production and mild upgrades). The intake and pushrod valvetrain are the biggest hindrance to any significant increase in power. Sure, BMC could utilize a better head design and slight intake tweaks to get 90-100 rwhp, but that's about it (and I'm not sure they'd meet EPA noise w/ it). They'll never go (w/ an EVO-based motor) Ti valvetrain, overhead cams, etc...which are needed to get any real big jumps in rwhp (say 130-150). Neil Garretson X0.5 | ||
| N. Garretson - Sportster List Race Team BBS Admin. (Lsr_Bbs) |
Oh, as far as the not practical to cast new heads, whatnot to help w/ the intake tract...or even to go overhead cams - which wouldn't be that difficult...it's also more of a packaging issue. The XL motor ain't exactly small for it's displacement. So even if you did move the intake to get a better intake volume and/or went to overhead cams, that'll just make it taller and harder to package...ya ever see how small a litre twin (i.e., 996, TL, or 51) is? They're tiny by comparison to the XL motor...and the 60 or 90 degree V actually allows for a better packaging arrangement, IMNSHO. If mother H-D can't put that motor in a sporty, you think BMC has the $$$ to develop these parts? Hell, look at the Buell thundertwin bikes, they're not THAT modified. Look at the VR, it's a rip off of the 888 w/o desmo, that's all. There's no real need/call for radical departures of what they've been making for years. I'm with [whomever said this weeks ago], it would have been very interesting to see what E. Buell would have done if he'd been working at Zuki, or Honda and used a modern, 60 or 90 degree twin. I'd bet you'd see something close to a naked RC51...as far as performance and reliablility. Neil Garretson X0.5 | ||
| Doug Lofgren (Moperfserv) |
Don't forget that changing to OHC would entail/encourage a de-stroking, which would allow shorter rods and allow the extra height of the OHC heads to end up at the same engine height. This would fit into the same package as the Sportster. (Other than the inlet which would be under the tank.) 90 degree engines don't package so hot either. When the cylinders get tilted back far enough to allow the crankshaft to be moved forward, the rear cylinder gets into the transmission. | ||
| N. Garretson - Sportster List Race Team BBS Admin. (Lsr_Bbs) |
Yep, and the destroking is just as much of a key to big HP as the OHC...as we all know, HP is a factor of RPM and torque. The faster it can spin, the more HP potential. Donna know, every 90 twin I've seen (ok, so I like Ducs and VTR's, been around ducs, have no idea what the RC's are like) had the front jug almost parallel with the ground and rear jug almost vertical...never gets in the way of the tranny or anything else. Allows plenty of room for carbs and good intakes, and because they're all short stroke, high reving they're no bigger than an XL (which is pretty good sized motor). Course that'd be the MoCo way, put a 90 degree twin, mount it like the current 45 and make that bike twice as long. ;) Neil Garretson X0.5 | ||
| Tim Slayter (Tims) |
Some time back I had STD Development Company cast up two front heads so as to run an XR style set up on my Buell. The main difference with these heads is that the exhaust ports have been move to the left-hand side of the bike, inlets are pretty much positioned the same but moved over to the right as far as possible. I did a quick fit when I had the bike apart for some top end work, recently, mainly to see how inlet and exhaust hardware will fit. The front head is the biggest problem due to the exhaust port exiting close to the frame ( front tie bar support, frame tube) and the inlet tract having to make a fairly tight turn to clear the rear head but admittedly nowhere near what the Y manifold has to contend with. Not an optimum setup by any means but am still hoping to make some good power gains. I still have concerns about cylinder head cooling as there is no finning where the orignal exhaust ports once were ( STD, for some reason, could not modify their casting process to fill this area)but was assured they will be fine. We'll see, but a bonus is this gap allows more room for the front inlet tract. Food for you Buell power heads anyway. Like to thank Doug Lofgren and Mike Roland for information they have supplied me in the past. Tim | ||
| Sean Pepper (Rocketman) |
Tim : please, please post some pics. Rocket in England | ||
| Jose Quinones (José_Quiñones) |
You wanted to see a VR....   | ||
| Jose Quinones (José_Quiñones) |
Here's some more interesting photos. From Buzz Buzzelli's Sportster Performance Handbook.   The text under these photos reads as follows... There is little information about the prototype that HD developed in the mid-1970's, reportedly designed and tested in both 880cc and 1,100cc versions. It has been rumored to have been a replacement of the iron Sportster, but it is unclear why the design did not proceed to production. HD refuses to discuss development programs that did not mature to production. Note that the entire front end and rear wheel assemblies are standard mid-1970 Harley issue. Also, the front and rear cylinder heads, which apparently have single overhead camshafts with a cam chain on each side, appear to be identical, so that a single head will work for either cylinder. This arrangement is identical to the Yamaha Virago that was introduced in the early 1980's. One particularly ugly rumor has it that a HD employee stole a set of plans and sold them to Yamaha. My comment: You think Buell might be dusting off these blue prints? Hmmm... | ||
| Jasonl (Jasonl) |
When I first saw that pic I was thinking "Why'd HD put a virago motor in a standard?" | ||
| Tim Slayter (Tims) |
Sorry Rocketman, no photos yet. I've still got a long way to go with this thing. Time and resources. Taken me 2 years to get this far. Eight months to get the heads cast from the US alone. 4 months to get the cams. Hope to run throttle bodies instead of carbs. Rest assured you guys will get a look. Tim | ||
| Jose Quinones (José_Quiñones) |
To answer my own question, I don't think Buell is going this way. What these pictures do show is that HD has tried various things in the past and who knows what they are up to now, but "tradition" has kept these prototypes from ever being produced. To me the interesting items on these pictures are the way they packaged the two carburators and the exhaust pipes. Looks like the tank is also the airbox and the ducts drop down from the tank and into a carburator on each side. I'm not sure where that rear pipe goes, it looks like it meets the two front pipes (?) somewhere in front of the rear wheel (like my 535 virago, actually). Anyway, interesting pictures. | ||
| Stuart Mungomery (Wet4uracing) |
Could you just bolt on a front head to the rear, weld up and machine the inlet and exhaust ports to point in the right direction and machine/source(XR)cams to make it work?Casting new heads seams aan expensive option.Why is it that you cant bolt XR heads onto a Buell,is it the shape of the combustion chamber? As you can tell I know didly squat about harley/buell engenering,but am interested to learn.stu. | ||
| BigHairyRalph (Ralph) |
Stu, right now about the easiest way to get dual carb heads on your Buell is Schumaker heads. Unfortunatly, they seem to unobtainium at the moment. Luckily for you (and me) STD is making the style head. Cast rather than billet, but that's okay. This style head uses the same exhaust location but two seperate elbow intakes rather than a shared Y. Another option would be Baisleys heads, which are set up like an XR's but I believe (don't hold me to it) there would be some problems with the frame and rider comfort. I'll be finding out for sure in a week or so. If you remind me I'll let you know. | ||
| Stephen Miranda (Stevem) |
I have a question for anyone out there who has had their FI apart. After removing the support plate, hook and tab, and injectors, I attempted to pull the outboard intake piece and throttle body assem. from the intake manifold.MAN are they stuck. The rubber seals between the pieces are holding like they have been glued in. I have pulled wiggled and twisted with two hands as hard as I dare.Is this common? Does any one have any idea's? SteveM | ||
| Doug Lofgren (Moperfserv) |
Stu, casting new heads is expensive, but it isn't an option, (for making 120HP from 1200ccs) it's (almost) a necessity. If you were able to purchase (at any price) the parts to do that, it would be the smart way. (I know that some people will work the rest of their lives, for free, to save a buck!) You can't make that kind of HP with marginal components, they have to have very good ports. The inlet length has to be right, the exhaust pipe has to be right, the cams have to be chosen properly, and the fuel system has to be calibrated properly. Anyone who can do all that, doesn't work for free. (having said that, I did all of the dyno work for free, but only once!) Make no mistake about it, this job can't be cheap. I do believe that one can make a very good performing separate inlet engine without everything optimized, but then you can get a 'cookie-cutter' 'Y' manifold engine that will make around a hundred. And that will be cheap in comparison. | ||
| Gus Garcia (Tavs) |
Guys: I just removed the charcoal canister off my bike (this is the smog stuff they put on CA bikes)so I could see more of the engine. The canister had three lines exiting out of it: one leading to the gas tank breather, another leading to airbox and another line leading to a nipple on the rear of the carb. I plugged off the airbox hole and the nipple on the carb. Now the bike seems to run hotter and pings in certain situations on WOT. Does this nipple on the carb do anything for enrichment? Am I running lean? Or am I just imagining it? | ||
| Ray Berry (Bigblock) |
I've been reading some interesting stuff about cv tuning in the archives here, and I'd like to add a thing or 2. I have a Vance& hines muffler, carb fiber ham can, 3" K&N, N6 cams, and a bitch of a time getting enough fuel. After numerous jet changes, and a Yost power tube and more jetting, I checked the petcock. After everyone I asked said the stock ones work great, I never checked. 12 oz a minute. That sucks!(it was clean, too) now I have a Pingel, what a difference! damn thing never ran like this before! So, I would say the first thing to do before ANYTHING else, is throw that stock piece of junk fuel valve in the trash! I have a 2000 M2. 6800 mi, i just put on my 3rd set of tires, went for d207's this time, they rule, i had Mich pilot sports last time, not as good, they dont hold a line as well, and stand up real hard on the brakes leaned, although they are as sticky(maybe) as 207's | ||
| Chuck Nance (Chuck) |
Thankyou Ray, I knew I wasn't crazy. About 10 miles before having to switch to reserve I can feel power "drop off" a bit. Thanks for confirming my suspicions. Please tell me how to get a Pingel --- On another subject --- Can anybody out there tell me if someone makes a vented "catch can" that might be suitable to run my breather lines into? Maybe Pingel, huh? Thanks in advance for everybody's prompt response. Chuck. | ||
| Tim Slayter (Tims) |
Nice one Ray. Aways wondered if those taps flowed enough gas. If you haven't done so, lets get some dyno figures. I've heard it said that the N6 is too much cam for these motors on the street. Tim | ||
| Chuck Nance (Chuck) |
Hey Tim, How's it going? | ||
| Ron Dickey (Axtell) |
Very interesting--- 12oz a minute 720 oz per hour 128 oz in gallon =5.625 gallons 8 lbs per gallon =45 lbs per hour useing .5 for a BSFC this engine can make 90hp thats at crank...-17% for rwhp=74.7 your petcock was your mainjet if you were trying to make more sustained hp GOOD INFO !! P.S. feel free to check my math ..did this in a hurry waiting for BHR to show up (snowstorm) | ||
| Jerome Chappellaz (Jerome) |
5.625 gallons per hour... If you run for one hour at full speed (say 135 mph), that makes 24 miles per gallon... Hey ! I thought that only a 1000 CBX with six 28mm carbs could do that, or maybe a Kawk 750 H2.... Is the petcock thus the limiting factor ? |
