CJS Customer Projects

Trimate 1098

I only had three days to work with these heads so I immediately set up an initial flow test measuring port flow with valve fitted and bare port flow (no valve fitted) to establish some type of discharge co-efficient .With a little bit of matching/applying a harsh stoned inlet port finish and adding a new multi angle valve job I was able to release a small amount of inlet flow.  I was quite disappointed hoping for much more of a gain but when the shape is good its good and Ducati did a good job this time.  However after running a velocity test it was revealed that the ports airspeed was quite lazy meaning the heads would respond very well to a higher lifting cam such as the 15mm lifting RS items.  Moving onto the exhaust ports a flow test revealed much improvement could be made.  The lower valve seat shape and throat size was strangling the flow giving the exhaust no ware near the amount of inlet to exhaust flow ratio I would like to see for a racing engine.  I changed the exhaust seat lower angle to a steeper cut which automatically opened   the throat diameter.  I then sculptured the exhaust port to a more adequate shape paying careful attention to the radius which did not exist in stock form.  After re- testing I had found to have made a very modest gain to the exhaust port. This gave me new confidence of giving this superbike some extra hp.

 

 Initial flow testing pulling 28 inches of test pressure through the inlet ports.

 

The finished inlet ports with stoned finish and a fresh  seat deal.

 

 After changing the seat angle far left to a steeper cut which opens out the port throat I set about blending the cliff face to create a  nice  radius ( right hand port) that the factory failed to make as standard.

 

The finished exhaust ports re-shaped and seats with  non standard seat angles applied.

Moto Rapido’s  engine builder  collected the heads and blueprinted the engine over the weekend.  A week later I received a phone call from steve saying the result was awesome and the rider could feel a big  difference with the  power hanging on for longer with no loss of mid range or tractable power.

 I wont be publishing dyno data for this bike as its confidential but I will say it leaves 1098r with full exhaust system for dead.  These heads will be back later in the year for some further development time.  If you want the same conversion just ask.

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