| Author |
Message |
    
Fullpower
| | Posted on Monday, December 01, 2003 - 01:59 pm: | 
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Kaudette, pretty sure you can run the xb9 primary drive sprocket and primary chain for an 11 percent shorter overall gearing. should be a real cheap mod, and it wont mess with your speedo at all. dean |
Fullpower
| | Posted on Monday, December 01, 2003 - 02:03 pm: |
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alex: if the compression stays the same, then the correct timing should be damn close to the same. |
Glitch
| | Posted on Monday, December 01, 2003 - 02:50 pm: |
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If the stroke is different, then the timing of the compression stroke would be different, wouldn't it? |
M1combat
| | Posted on Monday, December 01, 2003 - 02:52 pm: |
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I don't think so. It's all about TDC and both will reach TDC at TDC. If anything it wouldn't be off by any more than a degree or two if that. |
Buckinfubba
| | Posted on Monday, December 01, 2003 - 03:20 pm: |
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ok heres the story from people in the know.
It will work for a lil while, And I do mean a little while. Then physical damage will happen to your engine.
they would not go into detail but it was tried and it didn't work.
So take that for what its worth to you. I know I have offered my bike up for guinea pig status alot but I wouldn't on this endeavor |
M1combat
| | Posted on Monday, December 01, 2003 - 03:51 pm: |
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My guess would be fuel... Probably runs VERY lean. Maybe with a Techlusion box or a PCIII in the mix? Can those even be turned up enough to compensate? Is it even a lean A/F that causes the damage? |
Glitch
| | Posted on Monday, December 01, 2003 - 05:14 pm: |
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I know I have offered my bike up for guinea pig status alot but I wouldn't on this endeavor
That's enough for me... |
Alex
| | Posted on Tuesday, December 02, 2003 - 06:46 am: |
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I dinīt doubt that switching a 9 ECM to a 12 might kill the engine. I just wanted to know why a stroked engine would need different ignition timing. I have never seen a stroker crank using different timing marks than stock. And Iīve never heard that stroking has influence on flame travel speed. Dual plugging, raising compression or changing combustion chamber design: yes. Stroking ?
BTW the ignition pick up of the 12 is the same as the 9 pickup so min and max possible advance values should be the same. Sure the 12 has way different injectors than the 9 so risk is high that running a 9 ECM on a 12 will lead to fuel problems. Still I doubt that ignition timing will be the destructive factor.
Best regards |
Boulderbiker
| | Posted on Tuesday, December 02, 2003 - 08:37 am: |
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Hey I know, when I'm gettin real close to a re-build I'll just swap one in shortly before hand and tell y'all how it works
 |
Martin
| | Posted on Tuesday, December 02, 2003 - 01:15 pm: |
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Surely there is a relationship between stroke length and timing. If you divide the stroke by 180 degrees then each degree will count for a greater actual distance BTDC on a 'stroker' |
Glitch
| | Posted on Tuesday, December 02, 2003 - 02:43 pm: |
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That's what I was thinking. |
M1combat
| | Posted on Tuesday, December 02, 2003 - 04:19 pm: |
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Yes, but at the same RPM's, the time to move the greater distance will be the same because the crank journal is traveling faster. |
M1combat
| | Posted on Tuesday, December 02, 2003 - 04:19 pm: |
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BTW, It's not that I think the timing will be perfect... Just VERY close. |
Buckinfubba
| | Posted on Tuesday, December 02, 2003 - 05:22 pm: |
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close timing on these fuel injection models don't cut it very well....
it ain't a carb |
M1combat
| | Posted on Tuesday, December 02, 2003 - 06:43 pm: |
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Agreed, but the timing can be adjusted. I still think that it would be a lean A/F mixture that would cause the damage. I'm no pro though, so don't take my word for it. Just for the record, I'll not be volunteering my XB for guinnea pig status either  . 6800 RPM's is JUST FINE for me for now. |
Alex
| | Posted on Wednesday, December 03, 2003 - 06:54 am: |
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Well Gentlemen,
while still in doubt that a stroked engine needs different ignition timing - as it really doesnīt - a new aspect came into play: injected engines need the ignition to be dead on, close timing wonīt do, engine failure might be the result.
Let me ask some questions:
1. Do You believe that the ignition pick up cup is a high precision part manufactured to the closest specs industry can handle?
2. Doe You believe that the factory sets ignition timing a hundred percent the same on each bike that leaves Buell?
3. Do You believe that gear lash between pinion gear and ignition driving cam gear is zero for every engine?
4. Do You believe that pinion gear is positioned at the highest precision relative to the crank shaft?
5.Do You believe that the pick up cup is positioned precisely on the driving cam?
If Your answer is Yes for every question I will believe that a slight off ignition timing will destroy an injected engine. Otherwise I will believe that ignition timing will vary from one to another engine maybe by more than - letīs say 2 degrees without doing any harm to the engine.
BTW if ignition timing/injection timing was that critical wouldnīt at least 80% of the X1 have blown up?
Regards |
Bigj
| | Posted on Wednesday, December 03, 2003 - 04:00 pm: |
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Are you sure they haven't? |
M1combat
| | Posted on Wednesday, December 03, 2003 - 04:47 pm: |
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I think the tolerances we would be dealing with would make the difference in timing on a run of bikes less than 2 degrees... Granted, I just pulled that straight out of my arse, but I think the tolerances are a bit closer than 2 degrees.
I think the engine damage would occur when the ECM realizes it can't adjust to a proper A/F mixture and then falls back on it's preprogrammed map and runs WAY too lean. The head temps on the XB's (or so I have heard from many directions) are pretty high to start with, and they also run a bit lean to start with. |
Sspazz
| | Posted on Wednesday, September 21, 2005 - 03:40 pm: |
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I hate to revive this, but of all the searching (ya'll should be proud, I used the search function)I could do, this was as close as I could get to finding an answer. ....sooo....
Can you use the xb9 Race ECM on the 12 to increase the rev limit of engine? Maybe with the addition of the TFI? |
Dana P.
| | Posted on Wednesday, September 21, 2005 - 03:47 pm: |
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No!!!!!!!! |
Sspazz
| | Posted on Wednesday, September 21, 2005 - 03:56 pm: |
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thanks for the quick reply.. and pardon me asking, i am just curious.. why? |
Opto
| | Posted on Thursday, September 22, 2005 - 08:05 am: |
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No-ones done it and owned up to it, so I suggest giving it a go. I think it well worth trying.
Basically no-ones had the guts...
Edit: If someone wants to send me a 9 ecm I will fit it to the 12 and report back, simple, I live in Australia so consider small freight costs.
(Message edited by opto on September 22, 2005) |
