The V8 Owners Forum -

When you can achieve the same characteristics by a simpler mechanism, “the simpler the better”. This being the case, the system utilised by Ducati today is the simplest and by your definition, the best. No, this is not the case. The definition starts with "when you can achieve the same charact...

The first mention of a Desmodromic system is in 1896 and an engine was built in 1907 with it. Mercedes Benz's W196 engine used Desmo back in 1954/55 and Ducati has been using it successfully for years, but that system looks too theoretical to be practically efficient in my opinion. It's a proven re...

With a Desmodromic (i.e. rid of valve springs) fully Variable (the lift and the duration vary continuously and independently from zero to a maximum) Valve Actuation system (DVVA) like: http://www.pattakon.com/DVA_files/DVVA_side_cam.gif the revs and the peak power of a V8 (or of a side-cam engine, i...

The action of the Rhoades lifters depends exclusively on the revs (rpm). At 2000 rpm, for instance, either with full load, or with light load, the intake valve scheme is identical. In the MultiAir / UniAir, and in the PatAir, the lifter action varies (this is what the solenoid valves and the ECU are...

At http://www.pattakon.com/pattakonHydro.htm “clones” of the MultiAir (Fiat) / UniAir (Schaeffler-INA) are presented. http://www.pattakon.com/hydro_files/air.gif Officially, at urban cycle the Fiat Punto MultiAir (1368cc, 105bhp at 6500rpm, naturally aspirating) consumes 7.5 lt/100Km while the simil...

The basics of V8 patcrank VCR are shown in this simple gif animation: http://www.pattakon.com/tempman/V8_VCR.gif The main crankshaft (red) is conventionally supported on the crankcase and drives conventionally the flywheel and the gearbox. If you do not want to open the "exe" animation for...

I like the idea of the crankless GRECO engine. I think it would need helical gears though. I'm not sure how you'd share the power between the two crankshafts, and how you'd manage backlash as any backlash would upset the alignment of the piston assembly. Chris. Think of a three-inline Greco, as in ...

Looking at this it appears to me that the big ends would have to be prohibitively large in order to accommodate the additional secondary crank mechanism. http://www.pattakon.com/patcrank/patcrank1.jpg Also you end up with 2 sets of bearings per journal, one of which is constantly rocking across the...

[quote="katanaman"]Your obviously something to do with this site/company so I wouldnt be too surprised if you get a few skeptical posts. You like to compare patcrank system to other manufacturers, are there any real working engines out there with this system or is it all 3D modelling and a...

[quote="crayefish"]The trouble with it all is that its extra mechanisms and extra bearings and all that.... and if there is one thing I have learnt in my time it is that the more complex things are, the more likely they are to break, do what you dont want them to do, cause something else t...

With normal engines there seem to be problems keeping the crank located in the block, and even the block stiff enough. I can't see how it could be achieved realistically when you are moving the crank up and down, or am I missing something? . . . :D The VCR you are talking about is FEV's VCR that di...

[quote="crayefish"][quote="manousos"] . . . lol: not without flat diesel heads, very little valve lift and duration and a LOT of detonation . . . [/quote] Take a look at the desmodromic VVA (and the rest VVAs) in pattakon web site. At high compression ratios (which fit to partial...

Take a look at http://www.pattakon.com . The patcrank VCR in a V-8: http://www.pattakon.com/patcrank/V8_all_modes.jpg All it takes is four slim and lightweight secondary connecting rods and one thin and lightweight crankshaft, i.e. 5 lightweight, and cheap to make, moving pieces in total, plus one s...