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  #11  
Old 14-Jan-2009, 18:34
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Quote:
Originally Posted by skidlids
I have read recently on another website about a DD bike having its crankshaft balanced.

From previous experience of this type of work it usually include one of the following
Grinding Metal away
Drilling or Milling away metal
Weldiing to add metal

Now with the DD rules concerning Crankshafts having remained unchanged in this area since the very first set of rule for the 2005 Season V1.01 up to the latest set of rules, they have always stated NO MODIFICATIONS TO THE CRANKSHAFT ARE ALLOWED.

Current rule reads
1.6.21 Crankshaft
No modifications are allowed (including polishing and lightening).

The only way you can get round it is to have a large selection of pistons and rods available and to balance the whole reciprocating mass (ie crank, piston and rods) by substituting different standard OEM parts.

So once again, if you have the money and/or can go to the specialists you can get a better(?) motor than taking pot luck on what the factory puts together.

Although, from a purely hypothetical stance for a racebike I wouldn't see the point in balancing a crankshaft without lightening it as well, and then you may as well go the whole hog and use a lighter flywheel and flow the heads too...

Who's website was it? I've checked mine for typos!


Paul

15th year in DD #68 and getting slower by the year

1199, SS800 & 620SSie DD racer
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  #12  
Old 14-Jan-2009, 18:55
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Quote:
Originally Posted by vespa
..as if I have not looked for one...No chance. Let me know if you find one please.


because the front piston is grooved and I cannot find a replacement. A dealer
has a HC pistons but no OEM which are unavailable even in Bologna unless you buy the barrel.

I am not looking for increased performance, just peace of mind that my engine will not blow up. There is no point in giving out obviously not pertinent comment on forks and tyres.

Thanks

Alesandro,

I have confirmed this afternoon that the pistons are available from the factory, please contact Ducati Coventry and they will sort you out.

Ultimately the rules have been the same on balancing (that it is not allowed) since the start of the series and from memory we have only had one motor blow up (Ali's fire in year 1). To a certain extent balancing, expecially on the Class B engines is not worth the expense as they do not rev that high anyway and are somewhat overengineered for 52bhp.

Chris
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  #13  
Old 14-Jan-2009, 19:25
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What markings are on your piston, I have 2 used ones that are still very useable, Yours for now't if they are the correct ones.
Glyn

Quote:
Originally Posted by vespa
..as if I have not looked for one...No chance. Let me know if you find one please.


because the front piston is grooved and I cannot find a replacement. A dealer
has a HC pistons but no OEM which are unavailable even in Bologna unless you buy the barrel.

I am not looking for increased performance, just peace of mind that my engine will not blow up. There is no point in giving out obviously not pertinent comment on forks and tyres.

Thanks
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  #14  
Old 14-Jan-2009, 19:28
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vespa vespa is offline
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No Chis,
pistons for 583 are not available anywhere unless you buy the barrels and cost in excess of 350 pounds a piece. Baines has suggested to arrange production of 80mm pistons for 583 for DD which can be doen for appox. 70 pounds/piece but they won't be OEM...
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  #15  
Old 14-Jan-2009, 19:31
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vespa vespa is offline
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Quote:
What markings are on your piston, I have 2 used ones that are still very useable, Yours for now't if they are the correct ones.
Glyn
Thanks a lot Glyn,
What do you mean by markings? I know that the brand is MP but if you have 2 of the same brand available it won't matter. My front piston is grooved unfortunately...
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  #16  
Old 14-Jan-2009, 19:35
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Matt & I have spoken, well argued about this, what is the factory tolerence on wheight, is it "A" - x and + X if so, then that could solve the argument and the rules could be changed to allow balancing (only) of the crank, but not polishing or knife edging but stay with in the wheight tolerences of the factory original specification.


Chris
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  #17  
Old 14-Jan-2009, 19:35
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Scooter916 Scooter916 is offline
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Quote:
Originally Posted by vespa
Thanks a lot Glyn,
What do you mean by markings? I know that the brand is MP but if you have 2 of the same brand available it won't matter. My front piston is grooved unfortunately...
They have an A or B stamped on the top of the piston usually That is matched to an a or b on the Barrels.
Will check what I have and let you know
Glyn
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  #18  
Old 14-Jan-2009, 19:37
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Picked up a 8500 mile late 583cc Monster engine in October off Ebay for less than £300, then picked up a similar engine on New Years day for less and the guy had older 583 engines sat on his garage floor,
I'll dig the contact details out

The 1998 Monster engine in Dallas's 583 cost me £250 and without any carb work, cam timing or a like, just belts and oil/filter he was able to run at the front with Harriet at Cadwell.

The PB bike that Luke rode to a podium at Mallory had a bog stock engine, again not even a Dynojet kit and I doubt if the engine had been apart since it had left the factory in 1995.

As Paynep (humouros post Paul) well knows spending your money on track time can reap better rewards than spending it on the bike
ask yourself could another rider get your bike around the track quicker than you, if the answer is Yes, work on the riding not the bike

The problem isn't with balancing as I believe there is little to be gained for the cost involved, its the modification.
As there are two types of Crankshaft
1, unmodified
2, modified
the second group can include lightened, knife-edged, stroked and balanced, so for policing reasons Unmodified is the way to go


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  #19  
Old 14-Jan-2009, 19:52
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Quote:
Originally Posted by chris.p
Matt & I have spoken, well argued about this, what is the factory tolerence on wheight, is it "A" - x and + X if so, then that could solve the argument and the rules could be changed to allow balancing (only) of the crank, but not polishing or knife edging but stay with in the wheight tolerences of the factory original specification.


Chris

Chris it would not be easy to police, as I have already mentioned doing it on weight would require the crank to be fully stripped from the bike and then weighed on accurate scales and compare to a verified factory figure with a +/- tolerance.

and as the RC don't have to stump up any protest money (see extract from rule 2.1.1 below) is it worth the risk/cost of having a bike that is thought not to comply with the rules

2.1.1 Compliance Control
are placed in a parc-fermé for a period of at least 30 minutes.

Any motorcycle can be checked for compliance with these rules, and any other technical requirement, if requested by a representative of the DSC Race Committee.

The DSC Race Committee may require a rider or team to provide such parts or samples as they deem necessary without the need to resort to the ACU protest procedure.


At no point do you have to ask your engine builder to balance the crankshaft and they can't make you do it, the rules clearly say No Modifications, its the same rule for everybody.


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  #20  
Old 14-Jan-2009, 19:56
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I think Skids is referring to my post on Ducatisti, in my 09 prep thread, where I stated that my crank was ready to pick up after balancing. The crank and all associated parts are made with certain tolerances. When you hand the entire mass over for balancing ( crank, rods, pistons, gudgeon pins, circlips ) all thats done is to make sure that WITHIN THE FACTORY TOLERANCES the crank is not running out of balance. What I have had done is nothing to do with performance enhancement, just to try to ensure the engine doesnt fly apart. NOTHING has been lightened outside tolerances, NOTHING has been polished, its just been PUT TOGETHER PROPERLY, no more no less. Its a bog std 583 crank, with bog std 583 rods, and bog std 583 pistons, and bog std 583 gudgeon pins, and bog std everything. I have several engines and have mixed and matched parts.....so balancing is then an absolute necessity imho. NOT lightening or polishing, BALANCING. Its NOT been modified in any way shape or form, nor even has it been lightened to get to minimum factory weight, just put together to run evenly, bearing in mind it was an engine that I had bought that had been sat in a wet shed for a year, it all HAD to come apart as all the bearings needed renewing. No modifications could go so far as meaning using std gaskets instead of 3 bond for instance, or not shimming the crank to take into account the lack of gaskets today. the rules also state :
Wheels including diameter and rim width must remain as originally produced by Ducati since 1992 for the 600/620 bikes.
Front wheel 17” X 3.5”, Rear Wheel 17” X 4.5

but we all know 748/916 wheels are used......I think some common sense needs to prevail here.

Last edited by nogaromill998 : 14-Jan-2009 at 20:06.
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