Comments on: Ducati 748RS

By: Carbon-arc

Carbon-arc — Mon, 12 Jul 2010 00:26:57 +0000

Stealth

By: Chris

Chris — Sun, 11 Jul 2010 07:21:08 +0000

I think the power for this bike was mentioned as being around 120bhp or so. That’s a pretty good bhp-per-liter figure.

The valves are 36mm chrome-topped Menon racing valves, which can handle aggressive race cam profiles. According to Sigma, “After 750 km of racing use the chrome round the retaining ring groove is usually starting to break up”.

This is purely a function of the race setup — it’s no relation to the reliability of a road-going 748.

By: Bald Shaun

Bald Shaun — Sat, 10 Jul 2010 20:48:27 +0000

Very incitefull reply, Chromegelatin. One thing I have to point out though, the old 5,000 and current 7,500 mile intervals are for valve inspections, not necessarily adjustments. My valves needed no adjustment at 7,500 miles and I have heard of many late model Ducati owners getting 20k or more miles without needing any valve adjustments.
Obviously, the 748RS is a different beast. A sexy beast, though.

By: chromegelatin

chromegelatin — Sat, 10 Jul 2010 20:32:43 +0000

I’m guessing the valves have to be replaced every 750 miles because Ducati uses a desmodromic valve system. In essence the cams actually open and close the valves instead of just opening them and letting a valve spring return them. Way back in the day… Way way back in the day. The metallurgy of the springs meant that they would break under sufficient pressure, or they didn’t have enough resistance to return a valve back to it’s original position in sufficient time for high RPM operation. The desmodromic valves overcame this issue. Mercedes actually used an desmodromic car engine for a while. Until the last couple of years even two valve Ducatis had something like a 5000 mile valve adjustment interval. I believe it’s up to 7500 miles or something like that now. Now desmodromic engines are a Ducati signature. Something akin to a boxer engine in a BMW. At one point it was a technological advantage but now common motors have overcome the problems that these technologies once solved. Also it’s a high spec race engine, most only last a race or two at most.

By: BryGuy9

BryGuy9 — Sat, 10 Jul 2010 14:08:31 +0000

Can someone explain to me why the valves need to be replaced every 750 Miles?

By: Pamberjack

Pamberjack — Sat, 10 Jul 2010 09:23:01 +0000

Do we have any idea of the power and torque figures?

By: bruce

bruce — Fri, 09 Jul 2010 21:53:17 +0000

what a sled!