G oog le BadWeB | Login/out | Topics | Search | Custodians | Register | Edit Profile


Buell Motorcycle Forum » XBoard » Buell XBoard Archives » Longer connecting rods? « Previous Next »

  Thread Last Poster Posts Pages Last Post
Archive through May 17, 2006Hogs30 05-17-06  12:50 pm
         

Author Message
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 12:52 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Why Glitch,
They have different part numbers for sure..
You can`t buy rods for either separate you have to buy the whole wheel assemblies either the 12 or the 9 part numbers/???
Top of pagePrevious messageNext messageBottom of page Link to this message

Glitch
Posted on Wednesday, May 17, 2006 - 12:58 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Anyone have an XB12 and XB9 parts book handy?
Never mind the flywheel and the con-rods are sold as one piece.
Thanks goes to Chris (Deadman) at SMHD&Buell for looking this up for me.
Top of pagePrevious messageNext messageBottom of page Link to this message

Glitch
Posted on Wednesday, May 17, 2006 - 01:00 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Why Glitch
Just a thought.
Oh well...
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 01:05 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Yes Glitch,
they are sold as one unit either for the 9 or the 12...
The 9 and 12 both have different location holes where the Main Crank pin is located , as this is HOW the stroke is made for the 9 or the 12...
Crank pin hole for the rods located closer to the center = shorter stroke , location of hole out towards the end of the wheels = longer stroke and we are just talking about the difference of 3.18 and approx: 3.8 ( approx: 3/4 of an inch ) look it up in the specs. and all will see the difference in the strokes... Can I sleep now, I need my afternoon nap before going for a ride.. LoL
Top of pagePrevious messageNext messageBottom of page Link to this message

Hobanbrothers
Posted on Wednesday, May 17, 2006 - 01:12 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Hogs, with all due respect, I will only comment 1 more time as we are very busy rebuilding these same cranks.

We have rebuilt, stroked, de-stroked, lightened, knife edged, "Dark Horsed" well over 100 of this exact crank assembly.

We have rebuilt literally 1,000+ HD/Buell cranks in our Darkhorse Crankworks division alone.

9 rods are longer AND pin postition is different than in a 12 crank. I will wager a bet of any amount of $$$ you choose on this. I am not trying to be a smart a$$, but I am very busy and thought I could help in this conversation.

You can not solve this by looking in parts catalog as HD and Buell will only sell this type of crank as a whole unit, so, yes it will be a different part #, but trust me as I have been working with this crank prior to it being released in production models.

Flywheel 1/2s are essentially the same, production just puts stroke at where they want it. To do that with the same cylinders and pin location you must have a longer rod in a 9 to make up for shorter stroke. We make a unique stroke on some of our race motors that uses 9 rods and is neither a 9 or a 12, but I certainly do not want to confuse the issue more with regards to that.

Good luck with this, I hope this may clear this matter up for you. I can send pics with rods side by side to prove this, only if we put $$ on it though!
Top of pagePrevious messageNext messageBottom of page Link to this message

Speedfreaks101
Posted on Wednesday, May 17, 2006 - 01:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Hogs:

The rods make up the difference in stroke.

Look at this way. The stroke on the 12 is 3.812 and the stroke on the 9 is 3.125. We know that the pistons can be interchanged. Now if the rods are the same then that would mean that by installing 9 pistons into a 12 would raise them .687 in the bore. If this was the case the pistons would be sticking out of the bore. This easily tells you that the difference lies in the rods.
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 01:32 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

My point is... Longer rods = longer stroke Period. In saying that all things being equal with the 12`s pin location being the same as the 9`s Period
Now move the pin location in closer to the center of the wheels on the 9 crank setup than the 12`s that will produce a shorter stroke, ( higher revs ) WHY that would be done is strange to me....
Longer the rods more prone for stress/flex etc.etc..
So I guess the 12`s rods being shorter in length etc. are more beefed up STRONGER.
and lets not go into piston wrist pins locations...
So what you are saying is on the 9`s they have longer rods and move the crank pin closer to center of the wheels?? Interesting 100 percent different than what HArley Davidson does...or anyone else who builds a stroker in Harleys up to a point...
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 01:39 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Speedfreaks101,
I don`t think you have been following on the data with regards to pin location at all...
Sorry I have to stick to my thoughts on this, If thats the case longer rods and pin location closer to the center of wheels makes no sense to me at all...More rotaing mass etc.etc hmmmm Strange But for some reason perhaps thats why Buell changes their strokes with longer rods and pin location to make them rev higher still I`m shacking my head LoL...
Same rods different pin location = higher revs LoL

(Message edited by hogs on May 17, 2006)

(Message edited by hogs on May 17, 2006)
Top of pagePrevious messageNext messageBottom of page Link to this message

M1combat
Posted on Wednesday, May 17, 2006 - 01:49 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Uhhh.... Rod length has nothing to do with stroke length. The way they interact is that you want rods that are at least 1.7 times the length of your stroke to reduce side loading so that you can use slipper pistons. It's worth it to move to a longer rod so as to get slippers because they are lighter (off-setting the extra mass of the rod) and they cause less friction.

Oh... and rod length has nothing to do with rev limit either. Rod construction does, and more mass will cause an engine to rev a little slower, but it doesn't really affect the rev limit due to the fact that it's almost always the little end that stretches unless the rod was manufactured poorly.

So... Who's eating what?
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 01:52 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Micomabt,
Uhhh.... Rod length has nothing to do with stroke length

Hey M1 better watch it them words will get ya eating.. LoL
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 02:05 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

STROKER CRANKSHAFT The heart of any stroker kit is a stroker crankshaft. As the name implies, the stroker crankshaft increases the stroke of the engine. The longer stroke makes the piston travel farther in the cylinder, increasing the engine's displacement. That means that the pistons draw in more air and fuel on each intake stroke. It just makes sense that if you can burn more fuel, you can make more power, but there's more to it than that. Stroker cranks differ from stock cranks in that the crank journal, that the rods ride on, is farther from the center of the crankshaft. The added distance from the center of the crank shaft gives the pistons and connecting rods more leverage to turn the crank. That's why an engine with a longer stroke will generally have more torque than a short stroke motor of equal displacement.
This is how most HD`s since the early 70`s have done it...Not by making the rods longer... But perhaps Buell does it different... Just not what I have been use too...Xb 12 being the stroker compared to the 9.
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Wednesday, May 17, 2006 - 02:29 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I will add IF Buell does it by making the rods LONGER and also moving the rod pin in closer to the center in which they would have to DO , to destroke the 9... on the xb9`s to rev higher all other things being equal on the 9`s and 12`s why I don`t know then I will eat all of my above posts with regards to Buell Stroking... LoL

If not then you guys start eating LoL...
Top of pagePrevious messageNext messageBottom of page Link to this message

Old_man
Posted on Wednesday, May 17, 2006 - 02:35 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Buell destroked the 12 by moving the crank pin closer to the center and used a longer con rod to maintain compression. The 9 is a destroked 12, if you must look at it that way.
Top of pagePrevious messageNext messageBottom of page Link to this message

Xb9
Posted on Wednesday, May 17, 2006 - 03:34 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Hogs, I really think Hoban knows what he is talking about and it makes perfect sense.... If you just picture it in your mind it makes sense...

If you think he's wrong, put some money on the table.... I'll even throw in a wager ;)

(Message edited by xb9 on May 17, 2006)

(Message edited by xb9 on May 17, 2006)

(Message edited by xb9 on May 17, 2006)
Top of pagePrevious messageNext messageBottom of page Link to this message

Xb9
Posted on Wednesday, May 17, 2006 - 03:40 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

With the shorter (9) stroke you need the longer rod to maintain the same relative TDC position in the cylinder as the 12.

Since they both share the same cylinders and deck height, if you were to use the same rod length as the 12 the piston would not be reaching the top of the cylinder, unless you made up the differance with the piston pin position and or crown of the piston. I don't think you'd want to make up the 3/4" differance with the piston alone.

(Message edited by xb9 on May 17, 2006)

(Message edited by xb9 on May 17, 2006)
Top of pagePrevious messageNext messageBottom of page Link to this message

Xb9
Posted on Wednesday, May 17, 2006 - 03:50 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Old_man, your right I just read it wrong. My bad.
Top of pagePrevious messageNext messageBottom of page Link to this message

Djkaplan
Posted on Wednesday, May 17, 2006 - 04:22 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Okay, I'm back. I'm not sure exactly what more I can say, though, it's all been thoroughly explained rather eloquently by more than one person.

Surely you understand now, Hogs. It might help if you think of the 9 first and then thought about how to make a 12 out of it.

Hogs?
Top of pagePrevious messageNext messageBottom of page Link to this message

M1combat
Posted on Wednesday, May 17, 2006 - 04:28 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Freakin sheesh...

rod length has NOTHING to do with stroke length.

Stroke is DEFINED by the distance from the crank journal to the rod journal. Notice the period.

Yeah... It would be "inadvisable" to lengthen the stroke (which you would do ONLY by modifying the crank configuration) w/o also adjusting the rod length, piston shape, wrist pin location etc... but the STROKE has nothing to with the length of the ROD. You can use 16' rods with the same crank and get the SAME stroke length (you'll just need TALL jugs and you'd better do your homework on the harmonics).

You can not modify the stroke length by modifying the rods in ANY way...
Top of pagePrevious messageNext messageBottom of page Link to this message

Djkaplan
Posted on Wednesday, May 17, 2006 - 04:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

"The 9 is a destroked 12, if you must look at it that way."

I think looking at it that way is what confused him in the first place. I think he'd understand if he thought of the the 12 as a stroked 9.
Top of pagePrevious messageNext messageBottom of page Link to this message

Old_man
Posted on Wednesday, May 17, 2006 - 05:17 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Do you really think it will help?
Top of pagePrevious messageNext messageBottom of page Link to this message

Rocketman
Posted on Wednesday, May 17, 2006 - 06:41 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I can send pics with rods side by side to prove this, only if we put $$ on it though!

In future, this is the way I'll settle all my BadWeB arguments lol!

Do you really think it will help?

ROTFLMFAO again

Rocket
Top of pagePrevious messageNext messageBottom of page Link to this message

Djkaplan
Posted on Wednesday, May 17, 2006 - 08:20 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

"Do you really think it will help?"

Say... you were the one who started this whole mess, weren't you?
Top of pagePrevious messageNext messageBottom of page Link to this message

Old_man
Posted on Wednesday, May 17, 2006 - 09:12 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Guilty...I didn't think my simple question would cause this mess. I accepted the first answer that the difference was just the pistons but when Hobanbrothers answered, I am smart enough to believe the guy who builds them everyday. How someone, who has never held the parts in his hand, can be so sure that he(Hobanbrothers) is wrong is beyond me.
Top of pagePrevious messageNext messageBottom of page Link to this message

Diablobrian
Posted on Wednesday, May 17, 2006 - 09:53 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Actually I gave the second answer in regards to the pistons when you asked about the compression ratios, and asked if the pistons were the same. I assumed
at that point you knew the rods were different lengths. I forgot the old rule
about when you ass-u-me!
Top of pagePrevious messageNext messageBottom of page Link to this message

Cycleaddict
Posted on Wednesday, May 17, 2006 - 11:42 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

hogs must be FULL and taking a nap now------whewww !!!!
Top of pagePrevious messageNext messageBottom of page Link to this message

Alex
Posted on Thursday, May 18, 2006 - 02:23 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Want to be more confused?

A TwinCam con rod has a rod length of 7.667".
A Evo Big Twin has only 7.44".

Now which engine has more stroke?

Best regards
Alex (whom nobody seemed to believe when he said a XB 9 rod is longer than a xb12 rod until Hoban came)
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Thursday, May 18, 2006 - 06:57 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

HEy Cycleaddict,
YEah I guess I`m kind of Full... LoL
Not going to go into any thing here,Guess I sort of jumped into something with regards to the xb 9 and xb12 stroke Not Being used to TEaring these down and Building them up , So I`ll just say with regards to the Buells I APOLOGIZE To Those That Gave the Right answer,And I`ll Shut up on this MAtter... Lesson Learned !!!!
Top of pagePrevious messageNext messageBottom of page Link to this message

Djkaplan
Posted on Thursday, May 18, 2006 - 08:43 am:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Don't let it spoil your appetite for further discussions, Hogs. You are a regular member here and it's all been good fun.

It's a sign of character to take it on the chin when you're wrong, Hogs. Good show.

(I've eaten a few meals of prose and crow myself...)
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Thursday, May 18, 2006 - 12:47 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

HEy Djkaplan,
LoL, Your right....Its all in fun and Learning...!
Sometimes I can be a Stubborn Old Muller...!
Top of pagePrevious messageNext messageBottom of page Link to this message

Old_man
Posted on Thursday, May 18, 2006 - 01:10 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I want to thank everyone involved in answering the question I posed. It has been a sometimes frustrating but enjoyable couple of days. A special thanks to Hogs, you made it entertaining. You're a man.
Top of pagePrevious messageNext messageBottom of page Link to this message

Hogs
Posted on Thursday, May 18, 2006 - 01:18 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Hey Old_Man,
Thanks Buddy ...!
Top of pagePrevious messageNext messageBottom of page Link to this message

M1combat
Posted on Thursday, May 18, 2006 - 02:14 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I believed you Alex... I just hadn't made a post yet I think : ).
Top of pagePrevious messageNext messageBottom of page Link to this message

Old_man
Posted on Thursday, May 18, 2006 - 03:16 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

Alex, I believed you, but didn't get back on line til later.
Diablobrian, you misunderstood what I was asking but still added a bit of information about the differences. I understand now, after thinking about it, why a different piston is needed to maintain compression even with the longer con rod. With the piston reaching the top of the cylinder a flat piston, because of the shorter stroke would not have the same compression as in the 12.
Again, thanks to everyone who helped to enlighten us all.
Top of pagePrevious messageNext messageBottom of page Link to this message

Diablobrian
Posted on Thursday, May 18, 2006 - 04:45 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

It's all good : )
Top of pagePrevious messageNext messageBottom of page Link to this message

Rocketman
Posted on Thursday, May 18, 2006 - 07:43 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

No one's eaten more humble than I on the BadWeB. Now pissoff and leave my title alone

Rocket
Top of pagePrevious messageNext messageBottom of page Link to this message

Davegess
Posted on Thursday, May 18, 2006 - 10:46 pm:   Edit Post Delete Post View Post/Check IP Print Post    Move Post (Custodian/Admin Only)

I feel the love!
« Previous Next »

Add Your Message Here
Post:
Bold text Italics Underline Create a hyperlink Insert a clipart image

Username: Posting Information:
This is a private posting area. Only registered users and custodians may post messages here.
Password:
Options: Post as "Anonymous" (Valid reason required. Abusers will be exposed. If unsure, ask.)
Enable HTML code in message
Automatically activate URLs in message
Action:

Topics | Last Day | Tree View | Search | User List | Help/Instructions | Rules | Program Credits Administration