S'alright, looks only count. Wouldn't be ridden far.
Don't you look at my accountant.
He's the only one I've got.
While I am sure they might have recycled some parts, the life expectancy of an early 851 crankcase bored to full oversize and having its nuts revved off is far less than 300 km. Lots of early engines never even lasted a race. I know at least some Corse cases were sandcast; they went back to this again with later R engines.
This does not in itself not make them stronger ,but is cheaper method of making heavier designs and faster changers.
Later 888 models (1990 SP2) and onward are stronger but still not strong enough. The 916 is better, and the 996 is better again. Later deep sumps are better still. From memory, Cathcart was at times using one case per meeting on the tricolor kit bike, which is why it was almost brand new when he sold it. As even with his special relationship with the factory he could get all the cases he needed.
Every iteration was ever so slightly different, according to Rankin, with webbing and changes as the factory tried to make them work within the confines of the limitations of the molds and tooling they had. Also, the design, although better than the non-Mille bevels, still resembles a poorly designed product, as it has outer roller bearings under preload, which places loads on the case. The Supermono had plain bearings all around as an attempt to show what could be done with the next engine; Bordi had hoped to make the 916 like this, but they couldn't afford the new tooling. The rollers also limit the material and space they have to add material compared to plain main bearings. Remember the ducks have the two small outer outrigger bearings as well to stop the crankflap. if you look at the Ducati or even a old pommy parallel twin you can see why they need outrigger bearings.
While it's true the crankcase design goes back to. The pantah the gearbox centers were moved after the first pre 851 748ie as the 748 had to have a rather weak 6 speed to fit in the extra ratios I think they keep these centers with some later bikes, Maybe the 350/400 six speeds. edit seems to be 600/750's these were reused in the 800 series too according to BradB I have never questioned why, but I know The belt 750 cases at least up to the mid 90's don't fit the std 900/851/916 6 speed. (edit you can used the 6 speed from the 696/796/800.in the 600/750 5 speed cases)
looking into it The gearbox it seems was moved for to reasons the swing of the crank being one.
This kind of reuse old shit designs is not restricted to old pommy twins and shitty Ducati's have a look at almost any MF tractor up to the 1980 an you can see TEA ferguson DNA.
The Desmoquattro engine itself, with the valve spacing originally designed as a 748, (Bott around 86)
places the valves too close together, leading to the engines having to use almost two-valve timing. Plus, greater revs are needed to make enough power. It is said that later 996 works bikes had wider-spaced valves and special rockers, but I have never seen photographic proof.
My SP2 has the AA spec cams the are rather too much for the road even for a lot of tracks. Unless you are a works class rider. You can spend $$$$ chasing that last few HP.
If you have a look at the 748SPS you can see why the top ends were so short lasting
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Kinky is using a feather. Perverted is using the whole chicken
My information is heresay, ((heresy says correction) but came from Chris who used to work for Dallas) so same same
Don't you look at my accountant.
He's the only one I've got.
Sorry autocorrect got me twice!
Don't you look at my accountant.
He's the only one I've got.
The Duke of Wellington story mentions crankcase issues and how every set they got from the factory seemed to be different in some way
https://www.classicracer.com/dukes-wellington/
it's not a bad thing till you throw a KLR into the mix.
those cheap ass bitches can do anything with ductape.
(PostalDave on ADVrider)
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