| Author | Message | ||
     Old_man |
I'm curious if the 9 has longer connecting rods than the 12. Since the 9 has a shorter stroke and the cylinders are the same, either the rods are longer or they have different pistons. | ||
| 99buellx1 |
Different crank. | ||
| Old_man |
I know the crank is different, thus the different stroke. But with the same cylinders and connecting rods and pistons the 9 would have no compression. It either must have longer connecting rods or different pistons to raise the top of the piston near the heads. | ||
| Diablobrian |
the 12 has flat top pistons and the 9 has domed pistons. | ||
| Old_man |
Thanks, that was what I was curious about. I was hoping they used the same pistons and longer connecting rods. | ||
| Diablobrian |
Some have successfully hot-rodded their 12 just by adding 9 pistons | ||
| Sgthigg |
hummmm...going from flat piston heads to domed on a 12??? sounds interesting do share who did it? do we know him? | ||
| Alex |
Simple question, simple answer: Yes, the 9 has longer rods. The pistons have different domes but they use the same compression height. Regards Alex | ||
| Hogs |
As far as I know ,Same rods... Different hole position in the Crank location, Which raises the rods or lowers the rods in the Jugs... Which changes the stroke,Rods are of the same length,Correct me IF I am wrong??? | ||
| Djkaplan |
Either the pistons have very different pin locations, or the 9 rods are longer. The piston crown (dome or flat top) doesn't have anything to do with stroke. | ||
| Hobanbrothers |
9 rods are longer, that is a fact. The flywheels are the same essentially, they just put the crank pin location in a different location for the change in stroke. yes, by putting a 9 piston in a 12 configuration motor you raise the compression and it works well. Our spare motor that we ended up using in Daytona was that config and we took 4th place with it. The 9 rods are all on their own in length and design, the 12 rods are the same length they always have been and the same as an XL1200 or 883 for that matter. | ||
| Hogs |
So , Then the rods themselves are NOT Longer just the location of the crank pin in the wheels to give them a shorter throw, No difference in the rods for a xb9 or xb12 Just the location whole on the wheels...! | ||
| Old_man |
I'm glad to hear Buell did it the right way with the longer rods, rather than longer pistons. | ||
| Rocketman |
So , Then the rods themselves are NOT Longer just the location of the crank pin in the wheels to give them a shorter throw, No difference in the rods for a xb9 or xb12 Just the location whole on the wheels...! Ever heard of Hoban Brothers?? Guess not?? Rocket rotflmfao | ||
| Hogs |
9 rods are longer, that is a fact I wd. say that not to be correct... If they were longer and in the same whole position that would equal a longer stroke and wd. NOT rev. as high.. Where the 9 revs higher than the 12 has to be either by a shorter stroke ( rods ) or the location hole in the wheels for the crank pin to be in a different position than the 12 to make the 9 rev. higher.. I believe the rods are 100 percent the same in length...for either a 9 or 12 , just as I said the crank pin location hole is moved... Different pistons wd. just effect the compression not the Stroke in this case. (Message edited by hogs on May 17, 2006) | ||
| Hogs |
So what do ya mean Rocketman?? ROTFLMFAO LoL | ||
| Hogs |
Longer rods, would cause a bike in this case a xb9 or xb12 not to REV as high PERIOD One of the reasons the Metric bikes rev so damn high is their connecting rods are like 4 inches in length.. Look at any Harley rod and you can double that.. | ||
| Old_man |
Hogs, perhaps I can explain, the length of the connecting rod has nothing to do with the stroke of the engine,that is determined by the crankshaft. Because the 9 and 12 use the same cylinders the 9 needs either longer rods or pistons to reach near the heads because its crank is centered the same as the 12 but moves the piston a shorter distance. I hope I was able to explain. | ||
| Hogs |
Old_Man, I may be getting old But, really I still think its all in the location of the DAMN Hole in the wheels period... | ||
| Djkaplan |
Hogs, Before the day is out, you will be convinced that everything you just posted is wrong. If you aren't, well... | ||
| Hogs |
Pistons longer I don`t think so, the only thing that wd. change in the pistons is again now the location of the wrist pins in the pistons themselves.... | ||
| Hogs |
Okay Great prove me WRONG | ||
| Djkaplan |
"One of the reasons the Metric bikes rev so damn high is their connecting rods are like 4 inches in length.." They rev high because of the the very short stroke, not the short rods. | ||
| Hogs |
To change a stroke on your average low stroke now I`m talking about on a Big twin HArley , the only thing that changes is the location of WHERE the crank pin is drilled out on the flywheels, nothing to do with the length of the rods, By moving the crank pin location outer towards the outer diamamter of the crank wheels you in turn length the throw of the rods which changes the Stroke...All this up to a certain point only... Now changing the location of the wrist pin in the pistons themselves will also have a effect But this is not for the average builder to do...Lots go into this , and one has to do more Major specs. etc.etc | ||
| Hogs |
Djkaplan, LoL Rods are part of the makeup Buddy | ||
| Hogs |
Hobanbrothers, They were right in as "The flywheels are the same essentially, they just put the crank pin location in a different location for the change in stroke" Just the other remark ,But thats understanable... | ||
| Djkaplan |
I'm ROTFLMFAO, too. This is going to be good. I can't devote the time I want to show you (probably only you) why you are wrong right now. Be patient if you want me to specifically correct you. I suspect someone else will before I can come back. Choose your words carefully in the meantime because you will be eating them. | ||
| Hogs |
I believe what Hobanbrothers meant was, When they said " 9 rods are longer, that is a fact "... is that with the different location hole of the crank pin it does indeed decrease their throw making them able to rev. higher where as the 12 location hole is further out making the 12 having more of a stroke than the nine... Now I have been wrong once before correct me if this is not right? | ||
| Glitch |
Anyone have an XB12 and XB9 parts book handy? | ||
| Hogs |
Djkaplan, Don`t have nothing for supper as you may be full already.. LoL |
