Machining a 996 SBK engine to fit an S4 Monster

[FatAlan]

Hi all.

I have a bottom end from a 996 and an S4 that needs an engine. Looking on the internet there is a lot of information regarding the rear swing arm mount being different on the 996/916 to that of the S4. On the superbike the swingarm mounts to the frame as well as going through the back of the engine. On the monster it is mounted to the engine alone.

So. Whats the difference? How can I get my 996 cases machined to suit the S4 rear swingarm. I do not wish to go single sided and I do not really want to alter the frame.

Does anybody have any advice on what machining is required. I can strip the 996 down to the cases (I was planning on checking bearings etc before re-assembling the whole engine) so any advice or details would be greatly appreciated.

Thanks all!

Alan

[Kato]

Simple answer is -

The 996 engine is narrower at the swingarm pivot and does not have any bearings

You can machine your s4 cases to match a 996 swingarm
but
To get the 996 case to match the s4 swingarm you would need to have spacers made up, then welded to the cases then have them line bored to accept bearings, would be cheaper to buy another engine

[Dukedesmo]

You could use a double-sided swingarm from a 999 but you would still need to alter the frame to encompass the swingarm pivot.

But as per Kato's suggestion probably cheaper and certainly easier to get another engine.

[FatAlan]

Cool. I'll get on with the other engine obtaining.

[Kato]

or you could swap the 996 bottom end into your S4..

What exactly is the problem with your S4 motor ??