Doc Holliday
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With the lack of new information circulating, I decided to do some calculations based on the little information we have. Mean piston speed (MPS) can be an interesting way to compare engines. It tells us a little bit more about the stresses put on the internals at high rpm. We were told at the initial reveal that the 5.2L's increase in displacement over the 5.0 is "all bore," so we can deduce that they share the same 92.7mm stroke. Several shots of the cars show that the redline on the tach to be at 8,200 rpm. I compiled the bore/stroke for several modern, high revving, naturally aspirated performance engines of various configurations and calculated the piston speeds. I have them listed in order from highest MPS to lowest. Bore is not used to calculate piston speed, but I included it on the list anyway, just for comparison sake.
Engine / Bore x Stroke / Mean piston speed in feet per second @ redline
Audi 5.2L V10 / 84.5x92.8mm / 88.294 fps @ 8,700 rpm
Honda S2000 2.0L I-4 / 87x84mm / 84.514 fps @ 9,200 rpm
Audi 4.2L V8 / 84x92.8mm / 83.727 fps @ 8,250 rpm
Ford 5.2L Voodoo V8 / 94.5(est)x92.7mm / 83.13 fps @ 8,200 rpm [engine photos]
Honda S2000 2.2L I-4 / 87x90.7mm / 81.336 fps @ 8,200 rpm
Ford 5.8L Trinity V8 / 93.5x105.8mm / 80.993 fps @ 7,000 rpm
Ferrari 4.5L V8 / 94x81mm / 79.724 fps @ 9,000 rpm
GM 7.0L LS7 V8 / 104.775x101.6mm / 77.778 fps @ 7,000 rpm
Porsche 911 GT3 3.8L flat 6 / 102x77.5mm / 76.28 fps @ 9,000 rpm
Ferrari 6.3L V12 / 94x75.2mm / 71.549 fps @ 8,700 rpm
Lamborghini Aventador 6.5L V12 / 95x76.5mm / 71.112 fps @ 8,500 rpm
Ford 5.0L Coyote V8 / 92.2x92.7mm / 70.965 fps @ 7,000 rpm
BMW E90 M3 4.0L V8 / 92x75.2mm / 69.081 fps @ 8,400 rpm
GM 6.2L LT1 V8 / 103.25x92mm / 66.404 fps @ 6,600 rpm
There are a few things I would like to point out. The 5.8 Trinity is obviously not N/A, but with it's very long stroke (the longest on the list) and the over-rev function that will allow short runs up to 7,000 rpm in certain conditions, I knew it would have a high mean piston speed. Despite all of that, the Voodoo piston speeds are even higher.
Notice how much lower the piston speeds are on the standard Coyote, the GM LT1, and even the highly regarded BMW 4.0L V8. The very short stroke on the BMW gives it a much lower average piston speed, despite the slightly higher redline when compared to the Voodoo.
Also, notice that most of the engines are oversquare in design. The Audi engines are an interesting exception. I guess the engineers at Audi forgot that an engine has to be oversquare to turn high rpm. ;)
To me, this is one illustration of the level of engineering that likely went into the 5.2 for it to reliably achieve those piston speeds. Ford openly admits that they had to overcome several hurdles during development and that this was one of their most ambitious powertrain programs. There are some pretty exotic engines on that list.
I think we're in for a real treat.
Engine / Bore x Stroke / Mean piston speed in feet per second @ redline
Audi 5.2L V10 / 84.5x92.8mm / 88.294 fps @ 8,700 rpm
Honda S2000 2.0L I-4 / 87x84mm / 84.514 fps @ 9,200 rpm
Audi 4.2L V8 / 84x92.8mm / 83.727 fps @ 8,250 rpm
Ford 5.2L Voodoo V8 / 94.5(est)x92.7mm / 83.13 fps @ 8,200 rpm [engine photos]
Honda S2000 2.2L I-4 / 87x90.7mm / 81.336 fps @ 8,200 rpm
Ford 5.8L Trinity V8 / 93.5x105.8mm / 80.993 fps @ 7,000 rpm
Ferrari 4.5L V8 / 94x81mm / 79.724 fps @ 9,000 rpm
GM 7.0L LS7 V8 / 104.775x101.6mm / 77.778 fps @ 7,000 rpm
Porsche 911 GT3 3.8L flat 6 / 102x77.5mm / 76.28 fps @ 9,000 rpm
Ferrari 6.3L V12 / 94x75.2mm / 71.549 fps @ 8,700 rpm
Lamborghini Aventador 6.5L V12 / 95x76.5mm / 71.112 fps @ 8,500 rpm
Ford 5.0L Coyote V8 / 92.2x92.7mm / 70.965 fps @ 7,000 rpm
BMW E90 M3 4.0L V8 / 92x75.2mm / 69.081 fps @ 8,400 rpm
GM 6.2L LT1 V8 / 103.25x92mm / 66.404 fps @ 6,600 rpm
There are a few things I would like to point out. The 5.8 Trinity is obviously not N/A, but with it's very long stroke (the longest on the list) and the over-rev function that will allow short runs up to 7,000 rpm in certain conditions, I knew it would have a high mean piston speed. Despite all of that, the Voodoo piston speeds are even higher.
Notice how much lower the piston speeds are on the standard Coyote, the GM LT1, and even the highly regarded BMW 4.0L V8. The very short stroke on the BMW gives it a much lower average piston speed, despite the slightly higher redline when compared to the Voodoo.
Also, notice that most of the engines are oversquare in design. The Audi engines are an interesting exception. I guess the engineers at Audi forgot that an engine has to be oversquare to turn high rpm. ;)
To me, this is one illustration of the level of engineering that likely went into the 5.2 for it to reliably achieve those piston speeds. Ford openly admits that they had to overcome several hurdles during development and that this was one of their most ambitious powertrain programs. There are some pretty exotic engines on that list.
I think we're in for a real treat.
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