Flat Plane Crank LS1

[Bill]

Check out this video on the new 2015 Mustang GT350 flat plane crank. Starting at time marker 3:00, there is a quick explanation of what a flat plane crank is and its pros/cons.

Click -> here to view the video

 

[Mesa]

WHAT? Since when does a flat plane crank inherently have a shorter stroke?

Thanks Mark, I stand corrected. Although if they wanted to keep the 5 liter size then larger pistons would be in order and is there enough room in the block for that? Of course if they are doing this engine for racing purps then the regulations on size (in a racing app) would do more to dictate the final CCs.

 

[Mark Hamstra]

The video didn't say "inherently", but rather "typically" -- and that is correct: flat crank V8s do typically have shorter strokes in order to minimize the effects of imbalance and vibration. One of the things that I'm most curious about with this new Ford engine is just how bad the vibrations are going to be if it does maintain essentially the same stroke as is used in prior Coyote engines. That would be a very long stroke for a flat crank engine. On the other hand, if you were to destroke to about 4.5 liters, then the bore and stroke numbers would be very similar to those of the current Ferrari 458 engine.

 

[Roger]

WHAT? Since when does a flat plane crank inherently have a shorter stroke?

They didn't seem to know what they were talking about. They cited the fact that flat plane cranks typically have a shorter stroke as an advantage of the design, which is nonsensical.