I could be wrong but I seem to recall that standard 748, i.e. not SP/SPS have a smaller opening into the crankcase than 916, meaning 916 cylinders won't drop in. If so then you either need to bore the crankcases for the larger cylinder or turn down the cylinder but I think this leaves the cylinder wall a bit on the thin side. I believe there was a company (USA IIRC) that made specific cylinders for this purpose that had a stronger lining (possibly steel lined?) to overcome the weakness? 748SP/SPS and, probably R have the larger case openings so can use 916 cylinders.
I thought the 748 and 916 crank case openings were the same, the difference in diameter was the jump up to 996, like you I could be wrong. Steve
Yes im sure you are correct as I recall reading this recently about the cylinders being identical and just the bore is larger and also the crank has more throw .
996 has wider stud spacings so not compatible at all. With the 916cc block, 955cc (+2mm) was the safe limit, the first 996cc race bikes (built on the 916 block) regularly failed in racing as the cylinder walls were too thin due to the +4mm bigger bore leaving insufficient metal to cope with the pressures of a racing engine. This prompted the production of the true 996cc block, the first of which was the 916SPS.
Having just looked back, I think you maybe right about the 748 & 916 being the same bore in the crankcase. My confusion was for big bore 955cc kits for 916 engines where the SP or SPS model has a larger bore in the crank. The company that made the kit I was thinking of actually make the kit to fit 955cc to a standard 916 and not 853 to 748. Actually they make a kit that allows 748 to be upped to 890cc by utilising the same 96mm cylinders on a 748, more info here; DUCATI BIG BORE PISTON KITS Crankshaft Balancing Specialists
There are many options in regards to changing the engine 749/999/1098/1198 but there are a couple of issues. Getting a complete engine here (Australia ) and running gear is extortionate to say the least. Secondly I like the 748's revvy nature so would like to just improve on things and from what i have read and been told the 853 really wakes the 748 up so this interested me and I figured there is a lot of knowledge out there that I would be able to get the required parts easily and inexpensively(compared to here )from the UK and ship out here and have the motor built by an expert.
My 853R motor was built by Chris at CJS about 8-9 years ago. He used Pistal pistons sourced from here Tuning-Teile kaufen und Tuning Tips | Ducati & Aprilia-Tuning Kämna Looks as tho they do a kit for exchange cylinders also. I had my standard cylinders machined to take the pistals. Shouldn't be any fees for shipping to the UK
