Valve overlap

[manchild]

When I first saw this topic it reminded me on one article I read ages ago about cams in Porsche 917. Fortunately, today I've found that magazine again (printed in 1977 ) and it mentions 917 as an extreme - intake valve on Porsche 917 is open 388 degrees! It opens 108 degrees before... how do you say it in English... top dead point? and closes 108 degrees after bottom dead point?

[DaveKillens]

TDC = Top Dead Center
BDC = Bottom Dead Center

[manchild]

Thanks, I was close

[riff_raff]

Of course, the most extreme example of intake/exhaust overlap is the loop scavenged two stroke engine. The exhaust both opens before the intake/transfer and closes after it. That's 100% overlap!

[Belatti]

This is what too much valve overlap cause!
http://farm1.static.flickr.com/197/4999 ... 08.jpg?v=0

PS: Argentine TC champion, former F1 driver Norberto Fontana, with a 1400kg Dodge behemoth: 3 litres, six cyl. in line, 9500 RPM, almost 380HP.

EDIT: no electronic inyection, just the good and old webbers!