| Author | Message | ||
     M1combat |
I've replaced my '04 crank with the '08 setup. It's different on the left side. What is the torque spec for the left side of the crank? It's no longer a nut. It's a bolt. Thanks in advance. | ||
| Alex |
Don´t know about the torque spec but did You use the 08 sprocket and generator rotor as well? | ||
| M1combat |
Yes. Called customer service and they said 160lb/ft. The combo should work decently. I used a set of custom forged CP Pistons, the '08 crank, a mild port (mostly just cleaned up casting marks and that sort of thing) and bumped the compression to about 10.4:1. I had the heads milled flat too and it's .015" over bored. I doubt I'll notice the extra power but she should run strong. I might have the engine installed tomorrow if I can find a way to lug it down the stairs by myself... Maybe I'll just pile pillows up at the bottom and roll it? | ||
| Blake |
Pistons/domes match heads? Atop stairway, sit on lunch tray with engine in lap, you figure out the rest. Be sure to capture the effort on video. ![: ]](http://www.badweatherbikers.com/buell/clipart/proud.gif) | ||
| Alessio66xb12r |
Blake i read somewhere that you can use 08 pistons on previous xb models. you will gain 0.4 point of C.R. M1 and Alex is it possible to fit the 08 crank on a 04 construction engines with Timken bearings ??? if i remember right Hoban wrote here that you can do this swap only on engines with Imo bearings ( 05/06 and 07 models). bye Alessio | ||
| M1combat |
I just did it to an '04 and it seems to have worked  . I think all of the XB's have IMO bearings. I did have to replace the left side bearing but they were the same type. I don't know if the domes match the heads per se' but she certainly sounds good so far. The lunch tray idea worked great Blake , Thanks . On a side note... install the upper motor mount and coil bracket BEFORE installing the engine on an XB. You can do if after but I don't recommend it. Also... install the push rod covers BEFORE you put the jugs on. Oh, and place the aft starter bolt in the left side case BEFORE you install and torque the clutch/rear primary sprocket . Now to try to sneak that lunch tray back into the local school's cafeteria... (Message edited by m1combat on March 07, 2008) | ||
| Alex |
Alessio, what 04 construction with timken bearings are You talking of? Sportster? Shouldnt´they have the XB style bearing as well? I converted a XB crank to work with timken bearings some years ago for an older tube frame model but it requires machining. BTW so far I can not necessarily see the 08 crank to be better. Time will tell. | ||
| M1combat |
The improvement is in a larger connecting rod journal. Apparently there were issues with stretching the big end of the front conrod. This should make a stronger crank and conrod. They upped the rev limit on the 12 from 6800 to 7300 for '08. | ||
| Blake |
I think that the rev limit for the new '08 Buell big stroker engine is 7100 rpm. That's still a significant improvement to the powerband. If you consider the real red meat of the powerband as starting at around 4000 RPM, then that additional 300 rpm amounts to an additional 10.7% of pure Grade-A American animal protein. | ||
| Bombardier |
How much wider is the big end journal M1? | ||
| Alex |
See M1, I know of all the changes as I have a 08 crank on the table as well as an XBRR crank (which seems to have the same rod setup). I´m sure we will find out that the new style front rod will stretch as well on the lower bearing area as the old style did (every Harley/Buell rod will do that). Furthermore I never had a connecting rod bearing failure with the old rods in all my race engines (and we made plenty of miles under hard load). Only once a crank pin broke according to a material failure. That´s why I´m saying time will tell if the new style crank is the better choice. I hope it is but I´m not sure right now. | ||
| Blake |
If it runs to 9K rpm plus without failure would that be good evidence that it is improved? | ||
| Hobanbrothers |
Just a couple of items for your info here: The bearing as I call it is a INA (not IMO), they are the manufacturer of that bearing. You can not convert to a Timken style bearing with the 08' sprocket shaft because of the increased size, it is also considerably shorter. We have converted a fair amount to Timken bearings with earlier style flywheels. The crankpin diameter is 1.500" and it is not wider to any degree. The rods are essentially XBRR, same material and process. length is different in a 12 though. I believe although 9k would be a bit bold to go on a regular basis and with the weight difference would be hard to achieve with a stock crank. We have a 1 - 2 - 3 finish at Daytona between last fall and this spring at Daytona (the hardest track on cranks known to man) with the shortest duration being 2 hours and longest being 8 hours on 08' cranks all turning over 7,000RPM. That crank has proved itself to me. Nothing 04' (HD or Buell) except for RR had Timken bearings. Hope that helps... Good luck with your project M1, let me know how it turns out. John | ||
| Blake |
Isn't the diameter of the old crank pins 1.25", so the diameter increased by 0.25" or around 6mm. That is major. | ||
| Bombardier |
With the new oil pump and larger area on the bottom end bearing I can see how it would be better suited to abuse. Is there a lot involved in converting an 08 crank to fit into an 07? Also, would the old style pump be able to supply ehough oil volume? (Message edited by Bombardier on March 09, 2008) | ||
| M1combat |
There's not much involved at all. Just press out the old bearing and press in the new. Aside from that you use a new compensating sprocket and bolt (used to be a nut). John ... It went quite well thank you for the parts (Through Steve at GMR anyhow). I've got about 60 miles on it so far so no hard riding but I have run it up to 4K a couple times at mostly full throttle. Seems a bit stronger but what do I know... It's been three months since I've ridden it. I'm probably feeling the 10.5:1 compression more than the head work so far as there wasn't much head work done and I'm keeping the RPM's low. I was paying attention to cruise vibration and it seems there's less in this setup. There may be more higher in the rev range though... I don't know. I just realized... Because I let Steve buy the parts for me I never got a 10% discount . Such is life I suppose . "Also, would the old style pump be able to supply ehough oil volume? " That's a good question... Bearing speed will be higher due to the larger diameter so the oiling requirement should be a tad higher... I can't answer it . | ||
| Alex |
If You ever saw the oil metering plug in the pinion shaft end You would know the answer. It will definitely be ok with the old style pump. | ||
| Alessio66xb12r |
to Alex and Hoban my case has timken bearings xb 12 2004/march construction. i'm sure i read "timken" on the left side bearing bye Alessio | ||
| Blake |
John, By "Timken style" are you referring to spherical roller bearings (not ball bearings) versus a needle type roller bearing? | ||
| Alex |
Alessio, please post a picture if possible. | ||
| Jackbequick |
f this helps, there is a picture of a typical Timken roller bearing here: http://www.championscrew.com/timken.htm Those bearing are typically high precision and mounted with a some preload, even moderate to heavy preload in some cases. They are used in a lot of applications where a minimum of radial run out is wanted or tolerated. They also handle heavy side loadings very well. They are used on truck axles, machine tools, transmissions, and lots of other places. Jack | ||
| Alessio66xb12r |
....i noted "timken" when i did my xb conversion....i have no pictures of the bearings , i'll show you what i have in my pc. bye Alessio    | ||
| Alessio66xb12r |
some more   | ||
| Alex |
Your pictures show the right side bearing but we are talking of the left (primary) side bearing. Still it is easy to find out: 1.could You remove the crankshaft just by pulling it out of the left engine case or did You have to press it out? 2. did You need any special tools (bearing installer) to get the crankshaft back into the left case? Regards Alex | ||
| Alessio66xb12r |
Alex (many thanks for your time) i know is the left side you're interested about but now (bike completed) un possible to show , those are the only pictures i have. i remember ( i hope i remember right) it was necessary a big pressure on the crank to put it in and remove it out from the left case but NO special tools. i remember also the left bearing side was in 2 parts the "spherical roller bearing" ( NOT BALL BEARINGS ) and another round metal part that fit in the bearing area from the outside of the left case. i hope this help to find out. like you see ORDER is NOT my rule. bye Alessio  |
