Landracing Forum
Tech Information => Technical Discussion => Topic started by: desotoman on October 11, 2005, 01:22:08 AM
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When you couple two motors together, what is the best way for torque and HP? In otherwords if you had two 8 cylinder motors, would it be better to fire them as an 8 cylinder or a 16 cylinder? What are the gains vs. losses of running them different ways? Which way would be better for torque? I was once told that when you add a second motor, you only pick up 50% of its power overall. So if you had two 300 hp motors and you coupled them together you would only get 450 hp on a dyno. Any truth to this. I am sure the bike liner guys know the answer to this. Thanks for any help. Regards, Tom Gerardi
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If you are right about power loss when coupling engines together, Union Pacific has had it wrong for years. RF
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Power is just like weight. The scale only knows how much the total is.
Unless you have built in a delivery method that takes up power, the finished product will never know the difference.
Imagine a big guy and a little guy both pushing the same car as hard as they can. Who is doing the most work and who is going to get there first?
It goes without saying, but i am going to say it anyway. LOL
The coupler has to be strong enough, and the point of attachment, all the way to the delivery point strong enough to last. Most of the crank failures are as the result of moving around with power to the point the bearings will not maintain the separation and cooling provided by the oil.
That is all pretty standard stuff. What is not said is the timing between the motors. Each will have it's own power delivery characteristics and are independent of each other. What is important to the smooth transmission of the power is how they are timed between them. It is common practice to build a couple of degrees into the coupler so the front motor always happens just enough ahead of the 2nd to always load the coupler.
Long ago, 2 motored bikes would build a couple of degrees advance into what was otherwise identical motors. When setting the idle, they would make sure the top run of the chain was always tight.
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Hi Jack,
Back around 1985 I was helping my friend run his lakester at El Mirage. I was talking to the guy in front of us in line who was running a twin engine Harley liner and the motors were coupled together. I asked him if it mattered if they ran the motors as one big twin or as a four cylinder. I believe his reply was that running it as a big twin increased the torque output. But I believe he told me that horsepower was the same in either configuration, in which the second motor only added 50% of its horsepower. Just trying to find out if anyone else has done dyno tests like this and what the results were. Regards, Tom
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Their are 2 HD liners built since the mid 70s with twin motors and neither ever ran El Mirage.
You are likely talking about Leo Hess who was running the old Bob George/ Dave Campos open twin. All 3 bikes were built by Bob.
You either misunderstood Leo or he was wrong.
The cranks were linked and the timing between them was as I described if he knew it or not.
Since then 2 open bikes and 2 liners (2 Suzis and 2 Kawis) have been built that link the output shafts without regard to timing the motors between them. The harmonics between them are dampened by the path taken in the gearboxes and clutches.
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Hi Jack,
The conversation was 20 years ago. I could have misunderstood what they were saying. That is why I posted. Thanks for your help. Regards, Tom
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Bob Moreland's Spkye bike at Bonneville has a pair of Harley engines - and has made a number of passes. I don't know how those engines are tied together.
There's a guy that runs both Maxton and Bville -- he's got a pair of Harley engines in his bike. I don't know how he keeps 'em together.
Tom Metty has so doggone many variations on a bike that he may well have a two-engine Harley going.
There -- three multi-engine bikes for you to chase down to see if you can get anything from the builders.
And then there's Dan Wright's streamliner under construction. He's got a pair of Suzuki bike engines, but I don't think they're linked by anything -- or, if they are, it's a fly-by-wire link.
I don't have any data for you -- just some suggestions of folks that might be able to provide clues to your quest.
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Hi Jon,
Thanks for the information. I will try and contact one of the people you mentioned. Thanks again. Regards, Tom
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Yup, Tom has a twin engine Harley. Think he calls it "the Ugly". Or the Good. or the Bad. Look for him at Speedweek. Got an addy somewhere if ya want.
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My forever sidecar streamliner cause its going to take forever to finish , has 2 Kawasaki motors side by side but offset to minimise the width,it uses both gearboxes which drive through a common jackshaft to the rear wheel ,gearchanges are coupled together and activated by air . Iwill be running them as an 8 cylinder with one ecu , don't know if this has been tried before ? but it was the easiest way for me to run 2 motors ,caveat they have not been run yet or for that matter fired up so its unknown if it will work
Gary
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Zotoman
Well there are only a few of us that actually run or have ran multi engine vehicles I can give ya my wisdom “Don’t do it!” It’s double the budget, double the parts, double trouble, double fun and double the pain in the ass. Dolan has built and raced doubles but he really enjoys double talk and riddles. I really think he enjoys seeing people foolish enough to try it. You are correct double engines are only 75% total increase in hp but doubles torque. After all torque is what pulls 3 mile long trains, torque is what pulls stumps, and torque is what pulls heavy streamliners with moon gearing to record speeds. Since my liner is only 27” wide it is too wide to fit onto my bike dyno and is too narrow to fit any car dyno rollers I have found yet. So exact numbers still elude me. My motors put out 360hp and 165tq in a bike chassis each. So I figure I have bout 500hp and 325tq to the rear wheels. That’s small block Chevy numbers. That’s why we had to have billet trans made cuz we were ripping them out of the cases. Than we were just ripping the motor mounts off the motors, now we just snap drive chains like shoe laces. But were getting there. Soon well have all the bugs worked out (damn wet salt)
As for your question bout 8 or 16 cylinders, 8’s fire at 45 intervals to clock another to fire at 22.5 would be possible but not really necessary. Spend your time figuring out how to make a bulletproof flexible coupler that will handle 1500 lbs of torque that wont break the cranks. I couple my motors through the output shafts. the motors sync through harmonics. It’s like a tuning fork, when these babies sing its sweeeet. I currently own that Bob George liner you saw on the dirt. It was coupled through the crank primaries. Last year Bob Mooreland and the easy rider liner’s crew chief Keith Ruxton, spent a lot of time with crank leed and timing Bobs motors. I know what there crank phase is but cant say its kind of there secret. Don Vesco’s double bike liners always had the trans cut off of the front motors and linked crank to crank. Don always had chain or belt problems due to crank speed. The Rick Vesco twin Yamaha engine liner I own has both motors coupled to the output shafts cuz the cranks run twin blowers. The Ack attach liner is coupled at the rear wheel. The front motor uses a jackshaft to transfer drive to the right side and then back to the rear wheel with a chain. The rear motor is direct to the rear wheel. Metty’s bike is crank to crank just like all Harleys and Max Lamby’s Vincent is crank to crank via come pretty awesome gear drives. Probably the best coupling I’ve ever seen. All the double Harleys, the Vincent, and Vesco’s liners ran one trans and all have had major trans problems. All these bikes double the HP and TQ but run it through ONE trans that gives it up. I run 2 trans to half the torque loads, after a few motors and a few grand we finally have the trans worked out. I also run 2 complete systems. 2 motors, 2 ignitions, 2 ecu’s, 2 turbo's, 2 waist gates. I tried linking the turbo's once, when I lost a valve in the rear motor it took out the front and rear turbo. I changed that crap right back to 2 separate systems. I have no problems shifting both motors, Jimmy Odem had a shifting problem with the linked system on the Ack liner once, but I think they straightened it out as Noonan has yet to have a repeat of the miss shifting. If your thinking strongly about car motors you should talk to Rick Vesco about Dons experiences with the twin Offy’s or Rick White about the twin Hemi’s in his dad’s 400mph liner.
Man I gotta stop now, I can go on and on ‘bout doubles but both of my typing fingers are getting tired. Maybe all this typing ‘bout double engines will get me double points!
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Man what a rip, I only got 17.7 points for that post and it took me 2 hours to type. Come on little A, give me at least a 1000 points and i'll teach dolan how to use the spell check :lol:
kr
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Man what a rip, I only got 17.7 points for that post and it took me 2 hours to type. Come on little A, give me at least a 1000 points and i'll teach dolan how to use the spell check :lol:
kr
Duelan misspels on porpoise..
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Come back to earth.
The test bike you were with in 1984 was a 2 engined, 2 trans machine built to test shifting and tires. It was built in 1979 to establish the methods to link 2 engines. After that Don built the 2 engined 6cyl Kawi that ran in late 79. Charlie Toy has it now in Arizona the last I heard. Nolan never ran a hemi anything. Always a BBC in that liner.
How do you explain the loss you are dreaming up ?
Have you ever seen a 16V-92 ? Don't tell them they have a loss. The Offys and the 2 SBC in Don's last car suffered from the same problem and it wasn't coupling. The Chebys for example riped on Vic's dyno but you put them in the car and they layed down with a super hot inlet temp that killed the HP.
If coupling engines kills so much power, how do you explain the Yamama TZ series ? Each jug is a separate motor.
"Riddles are mostly to make you think but they don't always work."
Try again.
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Come back to earth.
The test bike you were with in 1984 was a 2 engined, 2 trans machine built to test shifting and tires. It was built in 1979 to establish the methods to link 2 engines. After that Don built the 2 engined 6cyl Kawi that ran in late 79. Charlie Toy has it now in Arizona the last I heard. Nolan never ran a hemi anything. Always a BBC in that liner.
How do you explain the loss you are dreaming up ?
Have you ever seen a 16V-92 ? Don't tell them they have a loss. The Offys and the 2 SBC in Don's last car suffered from the same problem and it wasn't coupling. The Chebys for example riped on Vic's dyno but you put them in the car and they layed down with a super hot inlet temp that killed the HP.
If coupling engines kills so much power, how do you explain the Yamama TZ series ? Each jug is a separate motor.
"Riddles are mostly to make you think but they don't always work."
Try again
There he is again Kent, puttin you and some points down... :P Good thing he never shows up at a meet...good for you or him?
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Hey Jack
Yes I remember your double. You started one motor then put it into gear and let the clutch out to start the other motor. Yes Charlie still has the big red banana. Haven't heard from him in a while I think he is still planning to restore it. Didn't it have a belt drive coupling system system that ran over the top of the motors. coupling loss? I still dont think we are doubling HP I am using conservitive guesses for my bonneville pro software stuff. Do you know of a dyno that we can check my car. Hell i'll be there next week to find out for sure. Jack youve got the most experience with doubles than all of us. I thought the motors in Ricks dragster came out of the liner but sometimes I could be wrong. Have I ever seeen a 16v-92 ?hell I don't even know what that is! Is it somthin old? I still think I should get a crap load of points for that long post.
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Ya Hoo I love this points thing! I'ts adicting and i'm catching up with Doland. Give me 10 more baby!
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I had 3 race cars running this weekend that made a total of 32 passes over a 2 day event.
One of them broke out by .002 in the 8th and final round after winning his class and then racing the winners from 4 categories for king of the hill.
Those are grandsons that represent the 3rd generation of drivers that started with me in 1962.
With 41 SCTA record trophies, I think that represents some time spent with them also.
The 30 years in SDRC have not been without some time dedicated to the effort with suitable results.
If I am at an SCTA meet, I am not likely to check in with you.
Try again :roll:
Oh and for Kent. If you want to use a wheel dyno put the car on 1 roller of a full sized chassis dyno and spin their ass off. SDRC meets on top of one now.
The hp should always be measured at the point of delivery because that is where you use it.
A 16V92 is the spec for 2 V8 diesels with 92" per jug that are linked together by the ends of the crankshaft like Nolan's setup. A very common package the was even used in the over the road truck from Battle Mountain that ran Bonneville.
And for you points hustlers, they have to be sharp enough to stick , otherwise they fall on the floor and there will be no cigar.
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so if 2 is double trouble , then this will be ??
(http://img.photobucket.com/albums/v228/hawkwind/triple_4.jpg)
(http://img.photobucket.com/albums/v228/hawkwind/Boris-double_trumpy_0.jpg)
(http://img.photobucket.com/albums/v228/hawkwind/triple_3.jpg)
some of you older gents may rememner these and Boris ,by the way the triple will be running at the next DLRA speed week , as we prefer to inovate rather than stagnate :P
Gary
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The busiest sounding bike I ever heard was the triple H-2. Their is even a double engined Whizzer running around. Cranks that were designed to deliver their power from the ends were favored for linking together and has been done with everything you might imagine. The weak spot was the dry chain at crank speed that required a lot of attention.
They were more popular 30 years ago than now , but with singles running faster that the available tires, they are usually a lot of work.
Perhaps the DLRA can lead the way and remove the 2 engine restriction and that might take some of the heat off their desire to try a "Dustbin".
Some kids like John and Kent may have never seen them, but it is too late to invent them. LOL
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Hi Kent,
Thanks for posting. I hope one day you can get your liner on a dyno to see just what the difference is. And if you ever do please let me know. Thanks again, Tom Gerardi
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Hi Hawkwind,
Neat pictures. I bet that triple is a handfull. Best of luck with your project. Thanks for posting, Tom Gerardi
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16V92 engines are/were in the Joint Venture and Carl Heap's Phoenix, to name a couple of well-known vehicles. General Motors used to label their diesel engines with simple explanatory numbers like that -- the first # was the number of cylinders, the letter declared configuration, the last was cu. in. per cylinder. Ever wonder what kind of/size engine your 6-71 blower came from? Straight-six w/ 71 in./cyl. Ditto a 4-53? (I think that series was a 4-53).
See how easy it used to be? Now -- well, my Chevy trucks have Cat 3126E motors. Doesn't tell you much except that the motor is "E" -- which stands for "electronic".
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Perhaps the DLRA can lead the way and remove the 2 engine restriction and that might take some of the heat off their desire to try a "Dustbin".
:D
Done as of today the DLRA will now allow up to 3 motors and more if anyone is crazy enough to try :D the "dustbin" is going to take a little more effort :cry: but it will happen :wink:
Gary
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I have to agree with Jack D, if you connect two 100 hp engines together and measure the output it will be 200 hp, if it is 150 then 50 hps are going into heat some where and I don't see that happening on any of the multi engine cars or bikes. Although after seeing some of the various "coupling" methods there certainly could be some hp going out through some of the jack shafts and chains.
There is a liner being built that is 4 wheel drive with two engines that will have an engine to drive each set of wheels, not physically connected, except by the wheels on the salt but the engines will be connected electronically through their ECUs to maintain matching rpms. Interesting thinking.
Rex
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Chet Herbert's car has AWD and 4 BBC in line.
More power than he has figured out how to deliver.
"The problems are not endless, but certainly ahead of it's time." (ME) 8)
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Hi Rex,
Thanks for posting. Lets say you have two 4 cylinder 100 hp motors that are connected together, and they make 200 hp no matter how they are connected(firing as a 4 or 8 cylinder). What happens with the torque? Would you gain more torque from firing the two motors as one?(big 4 cylinder). Maybe the difference is in the torque and not the hp. What do you think? Regards, Tom
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The power delivery of the individual supplies doesn't change but is additive. The monkey motion of the delivery is the only loss. The characteristics of the power supply is it's own and makes it's contribution to the package. You can have any mix for example a turbo gasser and a 2 stroke, or a an electric with a turbine.
Remember it is just like weight, only the final number is what counts.
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Dare I offer something? How about considering the time element -- the time between the individual power pulses -- when you're adding the output of multiple sources of power? Am I right in thinking that when you're measuring Hp or torque you're seeing a result (on the dyno screen or meter) that's averaged over some finite amount of time, like seconds, even though the power pulses are only milliseconds apart. So what you're seeing on the readout is the added sum of whole bunches of power pulses. What the clutch, transmission, driveline, & tire is seeing is scads of pulses (real close together). Averaged power output might total what you need to push you down the track at XXX mph, but instantaneous power is what's snapping driveshafts or breaking teeth in the trans. or twisting jackshafts...or breaking the tires loose.
"Big-bang" vs. "screamer" motorcycle engine timing arrangements experiment with this, right? Big-bang placed all the power strokes within a small number of degrees of crank revolution - so the tire would get this one massive pulse of power (which might break traction), but then there'd be many, many degrees of no power for the wheel to stop spinning and regain traction -- waiting for the next big bang event. Isn't this one explanation of why the Ducati twins had so much success against the inline-fours, even when the twin had less hp numbers on a dyno? That is, the firing sequence was giving the tire time to relax and gain back some traction before the next big-ass pulse came along.
And if the above two rambling paragraphs are in the neighborhood of correct, might the same consideration be given to determining an advantage to carefully choosing what firing sequence multiple engines ought to have -- identical or staggered? Maybe the measured-on-a-meter hp and torque would be the same -- but mightn't one arrangement show a reduction in damage to the drivetrain/increase in speed down the racetrack?
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Hi Jon,
Thanks for posting. I think you are on to something. I remember when I used to go to Ascot, and watch the Nortons, Triumphs, and Harley's battle, someone saying the Harley had an advantage because of their V twin crankshaft relationship. They said the Harley's hooked up better on the dirt tracks because of the 90-270 degree design. Regard, Tom Gerardi
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Hi Jack,
Thanks for posting. If everything is just additive like you state, what do you think of Jon's post? Would it be better to run two engines as one Big engine? Regards, Tom
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Remember the Yammama 4cyl 2 stroke mile bike?
It had the best of everythimg from tires and riders to weight and HP. But was unrideable in a dirt track.
they even built a variation that had 2 jugs firing together in an effort to change the power delivery but it was still out of hand.
It was a real screamer, but just didn't do that job very well.
Recip engines are pretty job specific with limits by design.
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The bikes often exceed the available traction and that leads to slower speeds, reduced tire life and speed ratings.
Everything is a speed secret until you make it work for you.
I remember Vance Breese on his first trip to Bonneville with his HD road racer that dusted the factory cammers in part because it was narrower and that was kinder to the ability for it to hook up.
His riding skills made more of a difference on the road race track. Making the package small and hooking it up can often make up for a lot of power.
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To much good stuff to resist posting a long one.
First: The Yamaha TZ750 dirt bike. Jack was right, that engine was just to peaky to be able to get traction and that was really a function of it being a two stroke with expansion chamber dynamics that made the horse power peak narrow. Although Kenny Roberts did win the Indy mile on one in absolutely one of the most exciting finishes ever. He was in second on the last lap, one of the Harley boys was leading, well Kenny knew if he could get a good drive of the last corner, i.e. traction, he could win. So he laid it in to turn four and got the wheel against the cushion, rolled on the throttle and it hooked up and he blew by the Harley right at the finish. Man was the Harley guy surprised!
More TZ750 stuff: When Don Vesco set the world motorcycle record with his liner with two of the TZ750 in it he said the biggest problem was getting the thing to hook up when the engines came on the power ban, it would just spin the tire. Although he set the record he came back next with a pair of turboed Kawasaki 900s and as I understand it he would short shift until he got into high gear and then he would turn the boost up adding horse power as fast as the tire could take it. Jack probably has some good recollections of both of these engine combinations.
Torque and horse power: Remember it is horsepower that makes you go fast, especially at B'ville. Horse power is a measure of work, i.e. force expended over a distance where as torque is just a measurement of force about and axis. So you can have a jillion lb-ft of torque but at zero rpm you are doing no work so you aren't going any where. So if you couple two 100 hp motors together, you will get 200 hps and also twice the torque.
Singles, twins, fours, twingals etc. Seldom, every thing that you say in your post regarding power pulse etc is true for an ideal engine, which would be an engine with a moment of inertia of zero and a structural stiffness of infinity. Not many of those around so we have reciprocating weight, the rods and pistons, and rotating mass, the crank and flywheel all of these combine to make a spring/mass system that actually attenuates the firing pulses of the engine to take out or at least reduce the sharp peaks that we would see if we had the "perfect" engine, i.e. no mass, infinite stiffness. There was a very good article in "Cycle" mag a couple of months ago by Kevin Cameron, I think, about using heavy flywheels to calm down cam shafts. now I admit that this sounds like the two are not connected but read the article and you can see what affect adding rotating inertia has on smoothing out the firing pluses of the engine and how this can keep the cam from throwing the lifters off of the cam face. So my thinking would be if you have an engine that is really peaky but makes good power add fly wheel until it is calmed down and at B'ville the reduced rate of engine acceleration would probably not be noticed as it is the big V cube (speed the power of three) that we are fighting and at the top speed of a vehicle drag is much more of a force than accelerating additional flywheel weight.
Just some rambling please feel free to through me under the bus.
Rex
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What he said. 8)
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To much good stuff to resist posting a long one.
First: The Yamaha TZ750 dirt bike. Jack was right, that engine was just to peaky to be able to get traction and that was really a function of it being a two stroke with expansion chamber dynamics that made the horse power peak narrow. Although Kenny Roberts did win the Indy mile on one in absolutely one of the most exciting finishes ever. He was in second on the last lap, one of the Harley boys was leading, well Kenny knew if he could get a good drive of the last corner, i.e. traction, he could win. So he laid it in to turn four and got the wheel against the cushion, rolled on the throttle and it hooked up and he blew by the Harley right at the finish. Man was the Harley guy surprised!
More TZ750 stuff: When Don Vesco set the world motorcycle record with his liner with two of the TZ750 in it he said the biggest problem was getting the thing to hook up when the engines came on the power ban, it would just spin the tire. Although he set the record he came back next with a pair of turboed Kawasaki 900s and as I understand it he would short shift until he got into high gear and then he would turn the boost up adding horse power as fast as the tire could take it. Jack probably has some good recollections of both of these engine combinations.
Torque and horse power: Remember it is horsepower that makes you go fast, especially at B'ville. Horse power is a measure of work, i.e. force expended over a distance where as torque is just a measurement of force about and axis. So you can have a jillion lb-ft of torque but at zero rpm you are doing no work so you aren't going any where. So if you couple two 100 hp motors together, you will get 200 hps and also twice the torque.
Singles, twins, fours, twingals etc. Seldom, every thing that you say in your post regarding power pulse etc is true for an ideal engine, which would be an engine with a moment of inertia of zero and a structural stiffness of infinity. Not many of those around so we have reciprocating weight, the rods and pistons, and rotating mass, the crank and flywheel all of these combine to make a spring/mass system that actually attenuates the firing pulses of the engine to take out or at least reduce the sharp peaks that we would see if we had the "perfect" engine, i.e. no mass, infinite stiffness. There was a very good article in "Cycle" mag a couple of months ago by Kevin Cameron, I think, about using heavy flywheels to calm down cam shafts. now I admit that this sounds like the two are not connected but read the article and you can see what affect adding rotating inertia has on smoothing out the firing pluses of the engine and how this can keep the cam from throwing the lifters off of the cam face. So my thinking would be if you have an engine that is really peaky but makes good power add fly wheel until it is calmed down and at B'ville the reduced rate of engine acceleration would probably not be noticed as it is the big V cube (speed the power of three) that we are fighting and at the top speed of a vehicle drag is much more of a force than accelerating additional flywheel weight.
Just some rambling please feel free to through me under the bus.
Rex
Bravo Rex a most excellent ramble :D
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I believe Rex has got it right. Torque is what you use to tighten your head bolts horsepower is what you use to go fast. The fastest wheel driven car on earth uses an engine that makes very little torque but turns very fast. It has always puzzled me why someone would build a vehicle to go from 0 to 300 plus with 3 or 4 gears. I would use a 10 speed if there were one available.
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Great post Rex and I agree with you Ack that the more gears the better. Hooley and I have had this discussion more that once with him sugesting at times about putting a 2 speed glide in the Stude, especially since on one run he screwed up and went from 1st to 4th and still easily ran 190 on his lic. run. I say no way let's keep the 4 speed. Likewise I love the 4 speed overdrive in my truck, but don't see the point of one when people suggest running one in a LSR car. With the wide spread in the gear ratio between 3rd and 4th it is a bad choice in my opinion. Our close ratio Muncie has worked good so far, but we now need something that is stronger with a tall 1st gear and the rest close ratio.
I still belive that with a motor that is gear ratio limited (has to run a 4 speed) torque is very important. Bikes with their narrow power bands and high HP learned way back that more gears will help get the job done.
I just recently had a high school buddy and his son give me a '60's Suzuki X-6 250. I sold a number of these when I had my motorcycle shop and took one to the drags once with only mildly ported cylinders and ran 14.1 @ 94 mph. Not bad for an other wise stock weight 250 in '68. This was probably the first production bike to really take advantage of high HP, low torque and 6 speeds to get the job done. It is still a fun bike to ride.
I guess it is the package that you are dealing with that will determine the torque/HP thing.
c ya, Sum
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My first bike at Bonneville was a junk parts 250 Yamama. The closest ratio in the box was 3rd to 4th in a six speed. That is what I wanted for the final shift so I geared it to run the target in 4th. That meant it would not even move in 1st and needed a 25mph tow from the door handle just to get going in low gear. I always did it with the engine running.
The no dead motor tow starts except for liners came from the HD that sometimes would not start with a tow from the truck and when you let the clutch out the rear wheel stopped and spit the rider.
On the other hand, top speed of the meet in the low 300 mph range was set by a Blown Alky SBC in what started as a Sports Racing car in high gear only after the trans broke.
"What works for you is good for you. If it is faster than the other guy, it is the worst for him."
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Rex,
Thanks for the post. You and Jack have made a believer out of me. :) I guess the guy who told me that twenty years ago was pulling my leg. :( Thanks for the explanation.
Years ago I bought a Suzuki TM 400 dirt bike off a friend of mine who said it was just too peaky power wise to ride. He was right. You were either digging 4" trenches with the rear tire or not moving. I went to the dealer and asked if they made a flywheel for this bike, and they did. Had a choice of a two or four pound flywheel. I bought the four pound, put it on a lathe and cut the weight out of the center of the flywheel leaving the outside 1"of the flywheel in the stock configuration. I bolted that on the bike and could not believe the difference. I now had a bike I could control. It was not peaky at all, and still just as powerful. When the guy I bought it off of road it he wanted to buy it back. He could not believe the difference, in fact he could not believe that is all I did. Bottom line is, years ago I learned a flywheel can be a tuning tool most people overlook. Regards, Tom
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Look at the parts in a Model A motor and remember how it was used. Get some help with the flywheel.
So that was 20 years ago. I don't know much about the modern stuff, things might have changed. LOL
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"90-270 degree design"
H-D twin firing sequence is 315-405
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8) 2 engines are not dbl trouble or dbl pain .both trouble & pain go up by at least a factor of 4. He was right on about not doing it. Tractor pullers run all sorts of weird combos and figure that each eng will contribute what it can.
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Final Round - 1960 Smoker's Fuel & Gas Championships.
The Odd Couple Chrysler-Olds against Tommy Ivo's Twin Buick.
(http://www.standard1320.com/Ivo/Buicks/TwinBuick/Twin%20Buick%20Wheelie%20copy.jpg)
The Odd Couple later evolved into a Chevy-Hemi twin. Try tuning that! They were moderately successful too. There have been lots of twins in drag racing. Tommy Ivo's four engine was the peak of insanity. If two engines is four times the work than four engines is ???
In 1971 I ran a twin engine bike . . . well mini bike . . . with two McCulloch 125's. Both engines had oil filled slipper clutches that didn't engage until 7000 rpm. No gear box. If the tuning was off the harmonics were obvious, and the power went to hell. Set two records.
(http://pages.sbcglobal.net/dean4/_images/Twin.JPG)
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That race in the picture was forever called "The Hookup vs the Shut Up." A 90 inch WB was and is a handfull.
The class A bikers have lost the art of making the bike small , but they will re-figure it out again. :wink:
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8)Just happen to have a goodyear 11/16 dragway spcl with Ivo's name chalked on sidewall, grooved and run on stock car. presently on my lawnmower. Other discussion reminds me of local saying{horsepower is for going fast & torque is for pulling stumps}.
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The replacement of cylinder are in good position.
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Ice Machine Parts (http://www.nt-ice.com/)
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The replacement of cylinder are in good position.
okaaaaaaaaaaaaaaaaaay , lets just sit down and , um, talk about this....................
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AHHHHH!!!!!!!!!!! we heard the light swich pop on over here-----let us in on the----enlighment???????????? :-D
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All your base are belong to us
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got on wrong spot :-D
Well I'll say something anyway. A duel engine Harley was in line near us at El Mirage and I'm thinkin '' somebodys actually going to get on that thing?'' :-o
JL222
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There are a number of posts on this topic on horsepower, speed, and torque. This is my experience.
The Triumph engine I ran in 2007 produced 42 foot pounds torque at 3,500 rpm. The engine did not have much torque over 6,000 rpm so I ran a big 19 tooth countershaft sprocket. I ran just under 100 mph that year. I set the gearing so the engine was at about 6,000 rpm when I was going as fast as I could.
South Bay Triumph enlarged the intake valves 2mm and ported the head during winter 2007-2008. Now it had 50 foot pounds torque at 7,500 rpm. This is a 19 percent increase in torque and the bike felt about 19 percent more powerful. It was better, but not as good as I wanted. I was not happy. Lots of money spent for not much more get up and go.
I reset the gearing so the engine would be just past 7,500 when the bike was going to go as fast as it could. The countershaft sprocket size went from 19 to 18. The rear sprocket went from 33 to 34. This made a big difference. The bike went real fast. I scared myself. Life was good. The bike went just over 120 during the 2008 speed trials.
This made me do a lot of late night figuring and calculations. The gears and sprockets in a bike act as levers. The reworked engine, with its more high revving nature, was geared with a higher ratio (engine rpm/wheel rpm). It had a lot better leverage on the pavement and salt than the earlier low rev version.
This is my feeling, anyway, about why peanut sized high revving bikes go so fast. It is the gearing. Their high rpm engines allow them to be geared at higher ratios, and they use this better leverage to their advantage.