CJS Customer Projects

900 Superlight

 

This is Richard'S 900ss

Richard decided to restore his 900 superlight and I was given the task, on recommendation of building a smoother more powerful engine in a cost effective way making the most of all the standard engine components.

I decided a full engine blueprint would be in order with a fine balanced crank and flywheel assembly matched to its new high compression JE pistons.  I donít normally recommend the use of off the shelf JE pistons in a Ducati and this has nothing to do with quality reasons. The  900ss piston being an exception fitting the chamber , small end and piston pockets correctly .

     

The fine balanced crank reduces stress on the main bearings and allows a safer higher rpm limit.

The cylinder heads received a full flow bench work over making the port a more efficient shape without enlarging the ports main cross section which if improperly sized can kill power. The standard valves were kept but modified , polished and the valve seat angles were changed  . These cylinder heads now flow strong air above 9mm of valve lift which is approximately the cut off point of the standard heads with a much improved airspeed.

           

Ports before                                   Ports after 

After the heads were fitted and squish adjusted by using thinner base gaskets the standard cams were degree'd  to specs.

    

Richard had Tim at Motovation fit the engine and restore the bike.  The bike was run in and taken to Race Developments for a dyno tune . It delivered a healthy 88 BHP which peaked on one run at 89.5hp

I'm pleased with the result seeing that the bike is still only a 900 with standard valves and long manifolds. This leads me to guestimate a proper porting job on standard valves is worth 6 plus hp on a long manifold carby engine. Easily more (see bennos project ) if the powerband could be extended with short Malossi manifolds and cams.  So far the result is a very  strong , well balanced  and cost effective engine with an added  13 hp  over stock ! .

I thank Richard for giving me the opportunity to work on this bike and make this article possible.

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