Kurt Trieb, engineer from BMW F1, is the one who designed both the first KTM MotoGP engine used by the Roberts team in 2005, and the latest propeller which now equips the RC16s of Bradley Smith and Pol Espargaro.
speedweek made it a point to interview him to extract some information from him.
Kurt, how do you assess the progress KTM has made so far in MotoGP?
“It wasn’t a bad start. Mechanically, from the start, everything went well.
The problems we encountered were not such that we had to panic about it.
This situation was resolved during the testing period. »
In what areas were these problems? The unique electronics caused major problems for Honda. Was it the same with you?
“Electronics is still a work in progress. Engine-wise, we experienced some small cooling and pneumatic valve return problems during the first half of 2016, but it was nothing dramatic. »
Do you mean the same valve return system that you already used in Brno in 2005 with the 990cc engines of the Roberts team?
" Yes. "
What percentage of that old V4 ends up in the new engine, or did you start from a blank slate?
“The RC16 project was started on a blank sheet. In its design or in the way a casing is screwed on, there are certainly similarities. Otherwise, everything is different and new. »
The Bore X Stroke ratio is given by the MotoGP World Championship regulations?
“Twelve years ago, with the 990cc, the bore was 84 mm, now the maximum diameter is 81 mm according to the regulations.
We then had a 75 degree cylinder angle and a balance shaft. Our new V4 engine has no balance shaft thanks to a greater angle between the cylinders. »
So we can assume that, like Honda and Ducati, the cylinder angle is 90 degrees. Ducati has a crankshaft that rotates opposite the wheels, like the Yamaha inline engine. Honda and Aprilia imitated them in 2016: is this a universal recipe?
“I heard about the counter-rotation of the Ducati crankshaft. An interesting concept. But, for the moment, we are not there. So far we haven't planned it. In my opinion a new engine would be necessary. Or a development.
If at Ducati, where there was a lot of uncertainty in recent years, such a measure was taken, I find it a strong decision. »
Why was the decision made for a V engine? Suzuki is more successful with the current inline engine than with the old V4 concept. What are the advantages of V4?
“It is more compact, and in my opinion, the weight distribution also speaks for the V4. I think the V4 is a good concept. »
Have you been able to pick up any part of the Moto3 engine, although it runs at 13 rpm and the MotoGP does it at at least 500 rpm?
" No nothing. »
Do you have a seamless gearbox?
“Yes, Stefan Pierer communicated very early on that we had a seamless box from X-trac in England. »
Ducati supplies there too. Are they the same?
“I can’t answer that question right now. »
What water temperature are you operating with?
“With normal weather conditions, we're running around 90 degrees. In Malaysia, between 103 and 105 degrees. »
Igor Akrapovic said at the time that the KTM 990 cc engine was the most powerful MotoGP engine he had ever had on the dyno. KTM CEO Stefan Pierer already spoke at the 2015 Valencia GP about 270 hp. Can we contradict the boss here?
“(Laughs) No, not at all... I think we have no doubt about the engine's capacity. Especially since we've had some improvements since Spielberg's test. This is how it fits. But it still depends on how you measure power. »
Where do you measure it?
“At KTM, we take measurements on the crankshaft. And we measure without excess pressure in the air box. In these conditions, we are not far from 270 horsepower. »
