Ducati Sporting Club UK > DesmoDue Race Series > DesmoDue - General Questions and Chat > No Modifications - what does it mean

[skidlids]

Originally Posted by nelly

Only added after reading the first page, but now read it all
Frank brings up an interesting point....
If the big ends failed, would a crank regrind and oversize shells be illegal?? The rules, if followed to the letter, would indicate so. Surely common sense would prevail??
There's a distinct line between balancing and lightening.
I think the point made about "good practice" in building a good motor is well made. There's no performance benefit and policing it is nigh impossible.

With regard to possibly regrinding a crank after a blow up (how much would this cost against sourcing another crank) then surely the course of action would be to email the RC and seek permission to get it done.
Not unlike Paynep emailing and asking about using a different frame.

I agree that balancing a engine is good practice and to some extent this is carried out at the factory, but as the Desmo Due rules not only state no Modifications to the crankshaft but also that it should remain as it left the factory there are quite a few entrants out there that have followed the rules.

For example Senna3 had his engine rebuilt at Baines Racing last year including the fitting of two new pistons, Now I wouldn't dare suggest Geoff or John don't know how to assemble a Ducati engine be it air-cooled or water-cooled but they did not adjust/alter/modify the crank as they were asked to make sure it complied with the rules.

Surely it is one rule for all

Nelly I'm not sure how many Desmo Due engines you have built from the crankcases upwards, maybe none. But if you have, have you always applied best practice or have you left the crank well alone inline with the rules

[nelly]

A regrind and shells would most likely work out cheaper than sourcing another crank. You'd re-shell it anyway as a matter of course.

I've built several motors from the cases upwards, and yes, i always apply "best practices" so as to build a good, reliable motor.
If i was asked about balancing as part of a DD build, then i wouldn't have a problem having it done. I don't interpret it as being outside the rules.
The cranks are balanced at the factory. Further checking/balancing is merely checking that it's as close to optimium as possible. No different to setting the squish, filing the piston rings to make sure the gap is spot on, setting valve clearances, setting the air gaps on the pick ups........ There's more benefit to be had adjusting those than checking/having the crank balanced.
Who's to say that nog's crank went away, was checked and nothing needed doing? More than possible.
If i was asked to have the crank webs machined away and knife edged, then i'd suggest they take it somewhere else, if i was asked about balancing then i don't see the problem.

May well get asked a lot more now than in the last few years after this rivetting read

[skidlids]

Originally Posted by nelly

Who's to say that nog's crank went away, was checked and nothing needed doing? More than possible.

But the thread wasn't meant to be just about Nogs crank, although the thread where it was mentioned was the catalyst for the initial question "No Modifications - what does it mean"

To me and many others No modification means leave well alone, if it doesn't and relates to meeting factory specifications I'm wondering if I can afford this little lot


one of my con rods is slightly heavier than the other and both are heavier than the minimum weight quoted by the factory, I know what I will do I will balance them so that the meet the factory minimum weight. After all the engine will be smoother and less likely to shake apart

Same as above goes for the new pistons

Also my rear cylinder head has a lower flow rate than the front cylinder head and I know someone elses flows more than that, so I think I'll get someone to alter them so they both match the higher flow rate of somebody elses engine, so long as I don't exceed the class bhp limit

Just been comparing camshafts and found mine have a fraction less lift than my mates and are even different to each other, I'll have to get them ground to the factory tolerance that will give the best performance. I'm not modifyong them as thats probably how some left the factory.

After checking the combustion chambers one is marginally smaller than the other so what I will do is match the other one to it, a quick skim will sufice after all its not really removing material as thats how it should have left the factory it just good practice to balance them out.

Just found out so and sos flywheel weighs a tad less than mine but is still within factory tolerance, I'll have to adjust mine to suit.

Crikey how much
be better off racing in CB5s

[Lily]

Originally Posted by skidlids

lots of confusing stuff...


Crikey how much
be better off racing in CB5s

Kev

You don't actually have to do any of it you know so the expense to you is whatever you want it to be.

[skidlids]

Originally Posted by Lily

Kev

You don't actually have to do any of it you know so the expense to you is whatever you want it to be.

I know I don't, so far I haven't even taken a head off any of my DD engines as the series is about cheap racing which s why I signed up for it as soon as it was announced having just thrown a F400 bike owing me £4k in the skip, a bike which was going to have given me cheaper racing than SoT or Powerbike

But it doesn't mean someone will not do it, if the rules permit the cheque books often come out in the hope of gaining some advantage

Me, I normally just buy a couple of engines set the valve clearances, fit new belts, dial in the cams, replace oil and filter and then get on and race.

Although this season may be different as I have just emailed the list of engine work (ok its Blueprinting) to the RC to see if I can get approval for any of them as it may prove a cheaper route to finding the 7bhp to take me up to the class limit without having to invest in a FIM ECU

[nelly]

Originally Posted by skidlids

But the thread wasn't meant to be just about Nogs crank, although the thread where it was mentioned was the catalyst for the initial question "No Modifications - what does it mean"

To me and many others No modification means leave well alone, if it doesn't and relates to meeting factory specifications I'm wondering if I can afford this little lot


one of my con rods is slightly heavier than the other and both are heavier than the minimum weight quoted by the factory, I know what I will do I will balance them so that the meet the factory minimum weight. After all the engine will be smoother and less likely to shake apart

Same as above goes for the new pistons

Also my rear cylinder head has a lower flow rate than the front cylinder head and I know someone elses flows more than that, so I think I'll get someone to alter them so they both match the higher flow rate of somebody elses engine, so long as I don't exceed the class bhp limit

Just been comparing camshafts and found mine have a fraction less lift than my mates and are even different to each other, I'll have to get them ground to the factory tolerance that will give the best performance. I'm not modifyong them as thats probably how some left the factory.

After checking the combustion chambers one is marginally smaller than the other so what I will do is match the other one to it, a quick skim will sufice after all its not really removing material as thats how it should have left the factory it just good practice to balance them out.

Just found out so and sos flywheel weighs a tad less than mine but is still within factory tolerance, I'll have to adjust mine to suit.

Crikey how much
be better off racing in CB5s

Skids, I understand what you're saying. I do. Hell, it could well be happening. Who knows? There may be a vast selection of 583 parts under someones bench being selectively pieced together into finely matched component sets..... (and no i don't have any room under my bench )

I stand by previous posts though. I've turned work away because of what's been asked of me but I don't see an issue with building a good, reliable engine and if that included being asked to balance it then I would.

Just an aside though, if the RC do clarify the issue, and just suppose it was ruled against, how the hell would you check it?

[skidlids]

Originally Posted by nelly

Just an aside though, if the RC do clarify the issue, and just suppose it was ruled against, how the hell would you check it?

Be hard in this day and age with Human nature as it is
Honesty in racing and sticking to the rule book is diminishing each year, be it BSB or DD

[nelly]

Originally Posted by skidlids

Be hard in this day and age with Human nature as it is
Honesty in racing and sticking to the rule book is diminishing each year, be it BSB or DD

It's always been there though Kev. There's more forums around today though
Never saw Mike and Ago on one chatting did ya

[Senna3]

Ive got a good idea when we get to the meeting we all chuck our race numbers in a hat then in turn pick one out and wot ever number you get is wot bike you race we do this every time then we see who is who is it the rider or is it the bike

[faith-healer]

One word.

....Perspective


.....F1 teams employ top engineering consultants who go through the latest FIA rule changes to see what they can get away with.....

....then they employ lawyers to confirm that the engineers are right...or wrong.

Any rule book will be "exploited" to the enth degree IF the financial rewards are worth it.

Crankshaft balancing in DesmoDue...Class A or Class B is, as I said before, a NON ISSUE.