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Gilles
Joined: 11 Aug 2019 Posts: 17 Location: France
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Posted: Sun Aug 11, 2019 6:23 pm Post subject: Crankshaft rigging |
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Hello bimoty friends.
I am a retired mechanic and I just took charge of a V-due to restart (stopped for 12 years).
Following a broken piston, the engine was dismantled and never worked!
It is a Dell'orto 39 carburettor model.
First surprise and first question: the two pistons go up at the same time, which seems to me illogical for a 2 cylinder engine 2 times.
What do you think ?
Thanks
Gilles |
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Gavin944888
Joined: 29 Jan 2014 Posts: 572 Location: Essex....way South of Scotland
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Posted: Sun Aug 11, 2019 6:45 pm Post subject: |
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Gilles
Absolutely correct...totally illogical unless it is the Big Bang set up....which it is.
Illogical is on the Bimota crest just below the box of frogs...in Latin.
The big bang twin firing system was introduced....I think by Cagiva ....but I could be wrong....
but,....certainly from the MotoGP 500 era
Hope this helps your rebuild project and stops you drilling another hole for the second crank pin
Good luck
Gavin
The Scottish Engineer _________________ On an Island in the River Thames!
Cagiva Elefant 888/955 & adventure sidecar
Cagiva Elefant 999r engined
Cagiva BIMOTA Motard Concept
BIMOTA DB9 (with DB11 rear-end)
BIMOTA DB7-11 VLX MULE (build coming to an end)
BIMOTA DB11 VLX Supercharger |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Sun Aug 11, 2019 7:37 pm Post subject: |
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Confirmed...as Gav says....twin crank...but big bang motor...wish you luck....piston searching...hope you keep us updated....I have the full strip down workshop manuals on pdf to email if you wish...or download them for free from vdue.it
Last edited by 2bims on Mon Aug 12, 2019 9:37 pm; edited 1 time in total |
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Gilles
Joined: 11 Aug 2019 Posts: 17 Location: France
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Posted: Mon Aug 12, 2019 8:26 am Post subject: |
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Thanks for those quick answers.
Ok, that's correct but illogical ..
Yes I want the workshop manuals at the following address: gilbrn@orange.fr
Gilles |
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Moreno
Joined: 15 Oct 2018 Posts: 66 Location: Chiavenna (italy)
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Posted: Mon Aug 12, 2019 6:37 pm Post subject: |
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what was the cause of the break? it would be useful to understand the problem to prevent it from happening again .... the original pistons you will not find them anymore .... but I drive fiedler that reproduces them |
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2bims
Joined: 03 Apr 2010 Posts: 7292
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Posted: Mon Aug 12, 2019 9:39 pm Post subject: |
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Gilles wrote: |
Thanks for those quick answers.
Ok, that's correct but illogical ..
Yes I want the workshop manuals at the following address: gilbrn@orange.fr
Gilles |
Click and download them all for free here from the one and only trusted source....the man that bought the company and all 320 Bimota Vdues....theres lots of manuals so click and download one by one
http://www.vdue.it/manuali.php |
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Weed
Joined: 29 Dec 2013 Posts: 250 Location: Perth Australia
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Posted: Tue Aug 13, 2019 12:14 am Post subject: |
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When I get around to it I want to experiment with different crankshaft timings to see what differences I get with engine vibration & power |
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Gammaboy
Joined: 25 Feb 2016 Posts: 188 Location: Brisbane, Australia
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Posted: Wed Aug 14, 2019 1:03 am Post subject: |
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Weed wrote: |
When I get around to it I want to experiment with different crankshaft timings to see what differences I get with engine vibration & power |
If you move away from the "twingle" timing, you'll have to re balance the cranks completely, they're not balanced the same as a single cylinder crank and the balance is out of phase because of the twin crank 90° v-twin configuration. Personally, I wouldn't bother messing with it. |
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Weed
Joined: 29 Dec 2013 Posts: 250 Location: Perth Australia
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Posted: Wed Aug 14, 2019 11:51 pm Post subject: |
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Gammaboy wrote: |
Weed wrote: |
When I get around to it I want to experiment with different crankshaft timings to see what differences I get with engine vibration & power |
If you move away from the "twingle" timing, you'll have to re balance the cranks completely, they're not balanced the same as a single cylinder crank and the balance is out of phase because of the twin crank 90° v-twin configuration. Personally, I wouldn't bother messing with it. |
It is a project in the future Gammaboy when I run out of projects. I have a spare motor I can rig up to an engine dyno if I want to play. |
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Gilles
Joined: 11 Aug 2019 Posts: 17 Location: France
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Posted: Sun Oct 06, 2019 4:20 pm Post subject: |
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Hello
After going back up the engine with love and care, I have a big problem.
I turned on and after a lot of smoke, everything was fine.
First test on the road, and after 1 km at very moderate speed, big noise and more than a cylinder works!
A ring broke and damaged the piston and the cylinder!
Where can the problem come from?
Can we find a cylinder and where?
Thank you |
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Gavin944888
Joined: 29 Jan 2014 Posts: 572 Location: Essex....way South of Scotland
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Posted: Tue Oct 08, 2019 3:21 pm Post subject: |
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Sacre Blue.....hhmmm
There are latest new cylinders and pistons available at FRP in Germany.
I know he also has some second users stock ...less monies.
I also know that he is in Crete on holiday and not back till week 43
He is a member on this forum...he is an engineer and very helpful.
Search his forum name GUIDO......based near Nurburgring
Others on here may have more and better info......but I hope that this helps
Regards
Gavin
The Scottish Engineer _________________ On an Island in the River Thames!
Cagiva Elefant 888/955 & adventure sidecar
Cagiva Elefant 999r engined
Cagiva BIMOTA Motard Concept
BIMOTA DB9 (with DB11 rear-end)
BIMOTA DB7-11 VLX MULE (build coming to an end)
BIMOTA DB11 VLX Supercharger |
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Bud977
Joined: 03 Mar 2013 Posts: 525 Location: Sydney
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Posted: Tue Oct 08, 2019 9:15 pm Post subject: |
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Did you find the cause of the original damage and fix it? It could be the same issue.
It could have been failed big ends. The bits come up the transfer ports and wreck the top of the piston, ring and head. Did you check them?
A ring can't really break by itself. If you put the piston in backwards, the end of the ring can snag on a port and break the piston.
Do you have any photos? |
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Gilles
Joined: 11 Aug 2019 Posts: 17 Location: France
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Posted: Wed Oct 09, 2019 4:39 pm Post subject: |
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Hi, thanks
In fact, it is a screw and washer holding the crankshaft seal that is passed in !!!!
I do not know how to send photos
Gilles |
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vort28
Joined: 22 Mar 2010 Posts: 2194 Location: Northwest , UK
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Posted: Thu Oct 10, 2019 6:06 pm Post subject: |
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Pictures need to be uploaded to a web storage account , imgur/photobucket etc and then the link pasted in the thread. If it does not work first time generally we can get to the picture and help you post it. |
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