I've got a 900 MHR-82.
I wonder if anyone have tried put in a modern (shellbearing type) crankshaft in a squrecase. I've seen roundcaseengines with 748 cranks. Which basically fits straight into the crankcases. One problem is the shaftlength for the alternatorside and another thing is the stroke. 66mm for the 916 and 74,4mm for the )900 bevel. Could be solved with a higher piston or a longer conrod.
I'd love to have information about this at [email protected]
916 crank in a 900 squarecase.
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- Diana
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- Craig in France
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Re: 916 crank in a 900 squarecase.
My immediate reaction is that the lubrication system will need a lot of modification: roller bearing = low pressure, high volume; shell bearing = high pressure, low flow.hedton wrote: I wonder if anyone have tried put in a modern (shellbearing type) crankshaft in a squarecase. I've seen roundcase engines with 748 cranks.
But it's not impossible and it has been done - changing to a plain bearing crank, that is. Go http://www.ducatimeccanica.com/kevin_race_engine.html.
Ciao
Craig
Re: 916 crank in a 900 squarecase.
Thanks alot. Du you recommened to stay with the shorter stroke and longer conrod or higher piston. Or a longer stroke?Craig in France wrote:My immediate reaction is that the lubrication system will need a lot of modification: roller bearing = low pressure, high volume; shell bearing = high pressure, low flow.hedton wrote: I wonder if anyone have tried put in a modern (shellbearing type) crankshaft in a squarecase. I've seen roundcase engines with 748 cranks.
But it's not impossible and it has been done - changing to a plain bearing crank, that is. Go http://www.ducatimeccanica.com/kevin_race_engine.html.
Ciao
Craig
Hedton
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- Diana
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Woops! Ta, Martin .Martin Mille / SSD wrote:One to many dot's Craig
http://www.ducatimeccanica.com/kevin_race_engine.html
Ciao
Craig
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Re: 916 crank in a 900 squarecase.
Sorry, can't help you there - way beyond my engineering capabiliites ...hedton wrote: Du you recommened to stay with the shorter stroke and longer conrod or higher piston. Or a longer stroke?
Ciao
Craig
The big question is why? The crank wouldn't be a drop-in installation.The oiling system would require modification to supply high pressure to the crank.The timing gear drive setup would need to be adapted along with the primary drive etc. If you have a fully equipped machine shop and the skills it could be done but would it be worth it? It would likely be easier to adapt the squarecase sidecovers and make some fake bevel tubes to glue to a beltdrive engine. Read Kevin Brackens article about building his engine to get an idea of what is involved Or try and find a Mille engine to start with.Treated properly a roller crank is just fine and pretty reliable.