749r foto motore e upgrade a 848R

[ultras998s]

The 749R combustion chamber and valve seat inserts are about as good as a production engine gets. Lots of squish area and virtually no valve shrouding.

[ultras998s]

dopo un po di lavoroz..





Nothing secret here, just a good going-over and careful attention to the seat insert areas. The size of the intake ports are spot-on to my preferred numbers right from the factory. Eagle-eyes might notice some casting dimples left in the exhaust ports... you can't dig these out because it will ruin the shape of the port. The inserts would have to be pulled out, the port welded and reshaped and the seats put back in the make it perfect. It isn't worth it really in $$/hp.

[ultras998s]

Nice straight port leading to valves that are gigantic compared to Desmoquattro's.

[ultras998s]

The size of the exhaust port baffles me to be honest. Have Ducati discovered a new physics?

[ultras998s]

Lots of computer modeling done on this one!

[ultras998s]

Not only is it an "A" or "porkchop" design crank, but the counterweights are relieved on the inside as well. Pankle rods are nice but will require frequent maintenance.

Now Mv999R has learned the lesson!

[ultras998s]

Can you guess which one is the 749R valve? Can you also guess why a stock 749R makes about 15hp more than a stock 748R?

[ultras998s]

Can this really be called a comparison? The 749R features an exhaust valve nearly as big as the 748's intake valve!

[ultras998s]

A season of racing is over and now it's time to rebuild. The engine held up extremely well over 2005, no problems at all. Here is the latest phase of the project... 100mm bore!

[ultras998s]

Before as a 749 (blue) and after as an 848. (red) Building an 848R is not easy. It takes modified 999 cylinders, modified 999 head gasket, and custom pistons. The pistons ended up being 18g heavier than stock, so I had Ben Fox balance the crank. The kit 749R ECU is used with a Power Commander. I was able to get the fueling pretty good, but I would sure like to be able to mess with ignition timing, I think that would clean up the power delivery a little bit and add a few more hp. All in all, however, a 10hp gain for 100cc's with no other changes isn't too bad.

[Toledo]

Ma un traduttore, no?

[max999rossa]

quoto toledo !!! ....