The engine internals diagram seems to have springs on top of the valves. 'Desmodromic valve actuation', from what I've read abu Ducatis, is about actuating valve opening by rockers as well as for valve closing. Wikpedia only mentions 'overhead camshaft'. Can Gizmag/anyone clarify?

you can see just how much pollution these things spewed out compared to today's race cars. just look at how dirty the drivers faces are after a race, they have an outline of their goggles on their faces.
With all the pollution controls and race regulations today's cars are struggling to pump out the power these cars of yesteryear put out.

Definitly not desmo valves. circa 1953/54 BRM extracted 525bhp reliably and on one occasion 585 bhp @ 10,500 rpm from their 1.5 litre centrifugally supercharged engine. Boost of 70 psi was used. As for dirty faces, look how exposed the Merc etc drivers were to the elements. Current F1 drivers have no exposed skin tro get dirty!

Definitely no evidence of desmodromic valve actuation in the cut-away diagram above. The cams operate on pivoting followers, much the same as my BMW F800 engine (Rotax design).
Other sources put the first Mercedes desmo as being the W196 of 1954. (See http://www.topclassiccars.net/top-classic-mercedes-cars-all-time-hit.html)
Ducati use a spring only for final closure at low speed and it's a hair-pin type rather than coil as depicted in the cutaway picture above.

Good article - good length, reasonably challenging to digest. Broad coverage of intricacies.

If the engine had desmodromic valve gear, your illustration is wrong, sorry.

about the dirty faces of the drivers, dont forget tripoli grand prix is in a deserted area... and what you see on the video is the dust on the track climbing up not only the emissions of the cars.
Great report Gizmag

I don't lay claim to any great expertise in this field, but I believe the desmo system on the Mercedes was mechanically opened and closed, but utilized a light valve spring to keep the valve head from bouncing up off the seat.
Also, the photo of Stirling Moss and Dennis Jenkinson does indeed include Uhlenhaut, but I don't believe the man at the far left is Alfred Neubauer. Neubauer was much larger and more portly, and I think older when this photo was taken, probably following the success of the Mercedes in the Mille Miglia.
The picture of Uhlenhaut with the engine and frame shows one of the early 300SL cars.
Ralph L. Seifer, Long Beach, California

Aouch, and to think my father had the opportunity to buy one in the 60s for a FF 1,500, deemed too expensive at the time for an old racer... Aouch, indeed!

Excellent article Mike Hanlon.