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Webber's engine being Fired Up for last time - 22,000 rpm!


Andy_Bangle
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This is quite a common problem with the early 911 engines..... sigh.

 

With the vagueness of the original gearboxes is it VERY easy to hit 1st from 4th ont he downshift, sending the revs well past the red line. Most people who take their cars seriously upgrade the shifter to a Wevo to stop this from happening.

 

I have also seen cars where the throttle cable has snapped, dropped down and been picked up by a drive shaft and so held wide open..... :blink:

 

Anyway, what happens is that the valves become the weak point and because the cams are spinning so fast, the valves 'float', i.e. both become fully open at all times as the valve spring cannot operate fast enough to close them, which usually ends up with piston impacting valve, valve head or heads breaking off and becoming even bigger and inflexible objects in the combustion chamber, this then mashes the head, and piston and usually results in a cracked or completely severed con rod, which in turn ends up going through the bottom of the case or certainly belting about on the inside of the case enough to destroy it forever.

 

As all 6 cylinders are generally doing this, there are usually a lot of bent valves etc.

 

RPM to achieve valve float varies with the weight of the valves and the strength of the spring used to ensure it follows the cam lobe. The last of the 12 valve 911 engines, the 3.2's, had the heaviest and largest valves so suffered more than later models where valves were doubled up to 4 per cylinder and made of stainless steel or even titanium.

 

High revving engines, expensive to build, even more so when they let go.... :(

 

On modern cars everything is lightened, and the valves on your M3 are probably very light and have a large valve spring to get them back up into the head, given the red line is already 8,300, but wont be immune to this type of issue at a certain level....

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Renault F1 V8 engine on Mark Webber's car being fired up for the last time, with the limiter off! 22,000 rpm is achieved, I think Renault were just "grenading" the engines ..

 

The guy talking to Webber from 45 seconds onwards is my ex wife's uncle Kenny, he loves a bit of camera time and has had plenty this season! +++

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The guy talking to Webber from 45 seconds onwards is my ex wife's uncle Kenny, he loves a bit of camera time and has had plenty this season! +++

He got interviewed a few races back. I think it was just after Vettel had won the championship. I recognised him from one of your previous posts.

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The guy talking to Webber from 45 seconds onwards is my ex wife's uncle Kenny, he loves a bit of camera time and has had plenty this season! +++

 

Yeah, most notably on the F1 Forum the race Red Bull clinched both drivers and constructors, Jordan had a quick interview with him.  +++

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