G'Day Ducatters 8)
My vertical timing belt is noticably less tight (cold) then my horizontal timing belt (cold).
Normal or adjustment required?
Thanks in advance.
Some people adjust the vertical belt a little looser to account for the supposed higher head temps on that cylinder. I don't know how noticeable the difference should be. Maybe check with your shop
I check 'em HOT. [thumbsup]
Quote from: ungeheuer on January 20, 2011, 01:20:05 AM
G'Day Ducatters 8)
My vertical timing belt is noticably less tight (cold) then my horizontal timing belt (cold).
Normal or adjustment required?
Thanks in advance.
my .02, they should be equal. Trying to account for any temp difference might be tough. If you haven't already, check out the quick overview at:
http://www.ca-cycleworks.com/videos/ (http://www.ca-cycleworks.com/videos/)
He slides a 5mm hex between the pulley and the belt, and makes it so a 6mm won't fit. On both belts.
Quote from: SDkid on January 22, 2011, 08:30:28 PM
my .02, they should be equal. Trying to account for any temp difference might be tough. If you haven't already, check out the quick overview at:
http://www.ca-cycleworks.com/videos/ (http://www.ca-cycleworks.com/videos/)
He slides a 5mm hex between the pulley and the belt, and makes it so a 6mm won't fit. On both belts.
I agree they should be equal, but you can't use the hex key method on the DS motors.
Thanks for the advice fellas [thumbsup]
Raises a couple of questions.... 5mm?... Seems like a lot...
Quote from: humorless dp on January 22, 2011, 08:35:48 PM.... you can't use the hex key method on the DS motors.
If its not a totally stupid question..... Why cant you?
Quote from: ungeheuer on January 23, 2011, 03:27:18 AM
Thanks for the advice fellas [thumbsup]
Raises a couple of questions.... 5mm?... Seems like a lot...
If its not a totally stupid question..... Why cant you?
They moved the pulley locations on the DS motors so the 'belt slack' at the idler pulleys is different than on the older 2V. Not only can't you use 5mm, but the locations are different on the H and V cylinders. You are pretty much stuck with the 45 degree twist method or a sonic/optical frequency method.
The 5mm method also does not work on 2V water cooled or 3 valve motors due to the reduced expansion.
Quote from: humorless dp on January 23, 2011, 05:35:43 AM
They moved the pulley locations on the DS motors so the 'belt slack' at the idler pulleys is different than on the older 2V. Not only can't you use 5mm, but the locations are different on the H and V cylinders. You are pretty much stuck with the 45 degree twist method or a sonic/optical frequency method.
The 5mm method also does not work on 2V water cooled or 3 valve motors due to the reduced expansion.
What he said. You were paying attention in class.
5mm is way to loose on our engine do not use this spec.
Quote from: DucNaked on January 23, 2011, 08:52:26 AM
What he said. You were paying attention in class.
5mm is way to loose on our engine do not use this speck.
I was not...
I was sleeping. :P
Quote from: humorless dp on January 23, 2011, 05:35:43 AM
They moved the pulley locations on the DS motors so the 'belt slack' at the idler pulleys is different than on the older 2V. Not only can't you use 5mm, but the locations are different on the H and V cylinders. You are pretty much stuck with the 45 degree twist method or a sonic/optical frequency method.
The 5mm method also does not work on 2V water cooled or 3 valve motors due to the reduced expansion.
where could one (hopefully) borrow a sonic/optical tuner from? That is my preferred method once I get to that job. Also, you mentioned all the motors that the 5mm method wouldn't work on, when would it work?
Quote from: SDkid on January 23, 2011, 01:56:02 PM
where could one (hopefully) borrow a sonic/optical tuner from? That is my preferred method once I get to that job. Also, you mentioned all the motors that the 5mm method wouldn't work on, when would it work?
The commercial tools are pricey. I don't think a pro would lend one out.
You can use a guitar tuner that gives you the frequency. There are also downloadable programs you could use with a laptop. Do a search here on the forum. The problem is you can vary the results by how hard you 'pluck' the belt. That is where the twist check comes in and that involves some feel/experience. Like a chain, a bit loose is safer than too tight. Too loose and all bets are off. If you do a belt tension and all of a sudden your tensioner pulley or idler pulley bearings start screaming at you they're probably too tight. The original Ducati spec was too tight and those bearings were failing left and right.
The 5mm method works on all 2V belt motors except the ones I mentioned.
Those would be 400, 500, 600, 620, 650, 695, 750, 800, 900.
Quote from: humorless dp on January 22, 2011, 08:35:48 PM
I agree they should be equal, but you can't use the hex key method on the DS motors.
I still use it as do others, 4mm allen.
Quote from: jwoconnor on January 23, 2011, 09:44:10 PM
I still use it as do others, 4mm allen.
Not sure how much drag is on the 4mm hex, but I bet if you tested your work with a meter you'd find them pretty loose according to spec.
It's your bike. Do it how you want. [thumbsup]
Quote from: humorless dp on January 22, 2011, 08:35:48 PM
I agree they should be equal, but you can't use the hex key method on the DS motors.
The way I understood Ducvets demonstration on the dualsparks is that they are NOT equal. I had my hands on those belts after he sonically set the tension and vertical had less tension. On that cylinder a 2mm allen may have fit between the belt and pulley. The horizontal one I don't think a 1/2 mm would have fit.
Quote from: DucNaked on January 24, 2011, 04:34:19 AM
The way I understood Ducvets demonstration on the dualsparks is that they are NOT equal. I had my hands on those belts after he sonically set the tension and vertical had less tension. On that cylinder a 2mm allen may have fit between the belt and pulley. The horizontal one I don't think a 1/2 mm would have fit.
By equal I meant when adjusting you use either the same frequency or the same allen key to measure as opposed to intentionally leaving the vertical looser to account for increased expansion.
The actual tension is what it is.
Quote from: humorless dp on January 24, 2011, 07:11:34 AM
By equal I meant when adjusting you use either the same frequency or the same allen key to measure as opposed to intentionally leaving the vertical looser to account for increased expansion.
The actual tension is what it is.
He used the same frequency and the same allen would not fit by the pulleys. I assume that is because the tensioners aren't in the same exact place on the cyclinders. Or did I not understand him correcly? They had the same tension, but the tensioners themselves were in different spots so the gap wasn't the same.(my understanding)
Quote from: DucNaked on January 24, 2011, 08:08:01 AM
He used the same frequency and the same allen would not fit by the pulleys. I assume that is because the tensioners aren't in the same exact place on the cyclinders. Or did I not understand him correcly? They had the same tension, but the tensioners themselves were in different spots so the gap wasn't the same.(my understanding)
We're saying the same thing I think.
Whether the actual tension is the same or not is hard for me to grasp because of the varied pulley location. All we know is the belts resonate at the same frequency.
Also keep in mind that both belts are bowstring tight when the engine warms, so as long as they're not so loose that the belt skips when cold, or so tight that it takes out a tensioner/idler bearing when hot they're right.
Quote from: humorless dp on January 24, 2011, 08:16:03 AM
We're saying the same thing I think.
Whether the actual tension is the same or not is hard for me to grasp because of the varied pulley location. All we know is the belts resonate at the same frequency.
Also keep in mind that both belts are bowstring tight when the engine warms, so as long as they're not so loose that the belt skips when cold, or so tight that it takes out a tensioner/idler bearing when hot they're right.
[thumbsup]
Quote from: humorless dp on January 24, 2011, 08:16:03 AMAlso keep in mind that both belts are bowstring tight when the engine warms, so as long as they're not so loose that the belt skips when cold, or so tight that it takes out a tensioner/idler bearing when hot they're right.
^^ Sounds like a common sense approach to me and so that there is my "take-away" from this thread [thumbsup].
Hi there :)
I hope you didn't miss the new belt changing tutorial from California Cycleworks. I thought it will be interesting to watch how they determine the belt tension with a software guitar tuner. It's very handy and simple method if you have a laptop or PC in the garage.
Links to the videos:
part 1:
http://www.youtube.com/watch?v=oXUgtytXI9o
and part 2:
http://www.youtube.com/watch?v=ETUD6AfK2d8
The only thing I really dislike is the free software tuner they used in the video. It can't hold the peak frequency of the belt's vibration and you have to stare to notice it just for a very short part of the second. It can be caused by the low frames per second in this compressed video, but this forced me to find a better "free" software frequency analyser to do the job easily.
And I found it ;D
This is a link, for free download, of maybee the best instrument tuner for PC ever made. It works great and the most common thing is that it filters the desired frequency and shows it's value constantly, of course with showing it's change very accurately.
Enjoy: http://www.nch.com.au/tuner/index.html (http://www.nch.com.au/tuner/index.html)
And this is a video demonstration of it's possibilities to prove my choice of software for the job: Free guitar tuner helps find that Perfect Pitch (http://www.youtube.com/watch?v=Q-JG-qtg_Gw#normal)
It works really great with guitar too!!! Tested [thumbsup]
Rock on!
Ducati sells a special tool for measuring belt tension on their 2 valve engines. I don't know if it works on the dual spark engines. Somewhere, about 10 years ago, I found out that the ducati tool measures the equivalent of 10lbs of tension. So I purchased a cheap fishing scale which I used until I blew up that engine. The scale also works on bass, salmon, reds, and pike.
I use a combination of a fishing scale (saw it's use in the Haynes manual), the 5mm and 6mm Allen keys and the 45 degree twist.
By the way, how did you blow up your bike? You weren't alluding to a broken belt I hope?
Quote from: koko64 on January 27, 2011, 06:36:33 PM
I use a combination of a fishing scale (saw it's use in the Haynes manual), the 5mm and 6mm Allen keys and the 45 degree twist.
By the way, how did you blow up your bike? You weren't alluding to a broken belt I hope?
Don't know for sure what was the problem. I'm sure it had nothing do with the belt. Shortly before it blew up I had a valve job done and then had a dyno run done on it. The idiot tech that did the dyno run hit a 4 grand over red line. He may have stressed something that broke later.
Quote from: akmnstr on January 28, 2011, 09:26:10 AM
The idiot tech that did the dyno run hit a 4 grand over red line. He may have stressed something that broke later.
:-[ :-\ aw man, that sucks. :(
Quote from: akmnstr on January 28, 2011, 09:26:10 AM
Don't know for sure what was the problem. I'm sure it had nothing do with the belt. Shortly before it blew up I had a valve job done and then had a dyno run done on it. The idiot tech that did the dyno run hit a 4 grand over red line. He may have stressed something that broke later.
That would do it. 4 grand over :o!
That's terrible. So sorry to here that.
That's negligent.
The engine lasted about 2k miles after the dyno run so I can't go back to the shop, and the shop is in Anchorage and I now live in Texas. It was the Harley shop in Anchorage, the dyno runs used to be done by a fellow that went to Duc training and a great guy. My bad luck, he had moved on, when I brought the bike in for its run there was a rookie running the show.
how long does it even take for you to rev it 4grand over? I've accidently gotten my M944 up to 11,000 rpm. The engine was solid.
At least the valves wont float.
Quote from: jwoconnor on January 31, 2011, 05:40:28 PM
At least the valves wont float.
Might have been better if they had.
I can give witness that valves hitting pistons is a very bad thing.