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Posted: Wed Aug 20, 2008 10:11 am
by cbxtacy
Reversing the head makes the cams turn backwards because the chain is still turning toward the front of the engine. flipping the cams from side to side gets the cams turning the correct direction as far as getting the opening slope opening the valves.
Posted: Wed Aug 20, 2008 10:17 am
by cbxtacy
The ignition timing is no problem, Mike. Once the cams are working properly, Andreas will just make a new 'T' mark to set up the ignition. He hasn't got that far yet. The cams are not behaving themselves.
Posted: Wed Aug 20, 2008 10:41 am
by alimey4u2
cbxtacy wrote:Reversing the head makes the cams turn backwards because the chain is still turning toward the front of the engine. flipping the cams from side to side gets the cams turning the correct direction as far as getting the opening slope opening the valves.
My telephone book with two pencils proved you're right George...left to right & right to left & spin the cams around...

Posted: Wed Aug 20, 2008 4:42 pm
by cbxtacy
The rear cyl cams can't be timed like the front ones. First have to dial in the left exhaust and then set up the rest of the rear cyl cams as appropriate. Why are they so off? If the valves were directly below the cams, parallel to the cylinders, it would not be so difficult but you have to consider the angle of the valves becasuse even though the cams are now turning the correct way for the opening slope to open the valves, they're still spinning backwards in the rear head. Anybody else want to build a V12 CBX?
Posted: Wed Aug 20, 2008 4:49 pm
by Don #6141
Other than just for the engineering challenge, it doesn't make much sense - You could never ride it everyday anyway
Now a V-8 'Busa makes lots of sense . . . . and you can buy those ready to go. 400 HP from about a 250 pound engine . . . . and it's watercooled
Don
Posted: Wed Aug 20, 2008 5:07 pm
by cbxtacy
None of it makes any sense (400 HP V8 'Busa powered motorcycle VS less then 200 HP CBX V12 powered motorcycle). Now a Suzuki Burgman makes sense. Everybody sell your CBX's and buy them. It's a good thing common sense does not prevail. Would you like to have a Bugatti Royale? It doesn't even have airconditioning. It's a good thing Michelangelo didn't have a Wagner Paint Sprayer, what if Pope Julius II told Michelangelo to "Hurry up, Mike.".
Posted: Wed Aug 20, 2008 5:24 pm
by alimey4u2
Posted: Wed Aug 20, 2008 6:48 pm
by Don #6141
cbxtacy wrote:It's a good thing Michelangelo didn't have a Wagner Paint Sprayer, what if Pope Julius II told Michelangelo to "Hurry up, Mike.".
Who's urging you to get it finished, George?
As I said, it's an engineering exercise - If it takes another 10 years, that's just fine . . . . so long as it eventually starts and runs on it's own then it will be a 100% success. You don't even have to install it in a bike ;)
I don't think any of the 'Busa V-8's have ever been installed in bikes . . . . at least I've never seen one, but they use it in all sorts of small racing cars
http://thekneeslider.com/archives/2007/ ... er-455bhp/
At $30K or so per copy, it's a bit too expensive for most of us bikers to be playing with - Well, some of you guys with 3 or 4 CBX's can probably afford to tinker with one . . . . but I'd pick a better bike chassis to stick it in than an X if I were you
Don
Posted: Wed Aug 20, 2008 10:47 pm
by Rick Pope
I think Larry's right. It would be simpler to use gears to achieve proper rotation and know the stresses on the valve gear will not get goofy and cause catastrophic failure. Simple and neat.
But I'm no engineer.......
Posted: Thu Aug 21, 2008 5:10 am
by alimey4u2
cbxtacy wrote:The rear cyl cams can't be timed like the front ones. First have to dial in the left exhaust and then set up the rest of the rear cyl cams as appropriate. Why are they so off? If the valves were directly below the cams, parallel to the cylinders, it would not be so difficult but you have to consider the angle of the valves becasuse even though the cams are now turning the correct way for the opening slope to open the valves, they're still spinning backwards in the rear head. Anybody else want to build a V12 CBX?
Indexing between inlet & exhaust is limited to one sprocket tooth & there may problem with the "new" oldhams coupler orientation ??
Posted: Thu Aug 21, 2008 7:33 am
by EMS
Well, I am an engineer and you guys are losing me here...
Why is the valve angle of any concern? The cams are centered over the buckets, aren't they? The forces are exactly the same. And why would the Oldham couplings' orientation be a problem? If you flip the cams and turn the cams backwards the relative rotation remains the same...

Posted: Thu Aug 21, 2008 8:39 am
by alimey4u2
Just trying to work out what's going on here Mike. There is something going on that isn't obviously apparent...
Posted: Thu Aug 21, 2008 8:59 am
by EMS
Posted: Thu Aug 21, 2008 9:43 am
by cbxtacy
just cam timing for the rear cylinders. Wasn't where we expected it to be. Using a degree wheel to time them. Then drill new timing marks (or scribe?) in the rear sprocket's.
Posted: Thu Aug 21, 2008 10:17 am
by Don #6141
Well . . . . assuming the rear cylinders are sharing the same crank throws with the front cylinders, then you'll have to move the crankshaft off TDC by the same number of degrees as the Vee (45?) to get the rear pistons at TDC to set the valve timing . . . .
Is that what you're experiencing George?
Don