Flat Plane Crank LT5

[XfireZ51]

Originally Posted by tpepmeie

Dom,
Imagine the crank throws all on the same "plane", rather than at 90 degrees to each other. Usually it is "up, down, down, up" for the 4 rod journals. Still have a cylinder event every 90 degrees, but they alternate banks (Left, Right, Left, Right, ...). And all the firing intervals are evenly spaced on each bank. Helps exhaust tuning quite a bit, and all cylinders exhibit the same airflow performance. On a 90 degree V-8, certain cylinders can perform up to 8-10% worse than the best cylinder due to exhaust tuning (mainly the closely spaced (90 degrees apart in the firing sequence) cylinders on each side.).

The downside... a considerable secondary shake, in the side-to-side axis. Not as naturally well balanced as a 90-degree crank. And-you can't run a large stroke due to this vibration.

Todd,

Thanks. I thought the name denoted basically a 180 journal config.

[Fully Vetted]

Because of this configuration they are absolutely insane when under boost.

[XfireZ51]

Originally Posted by Fully Vetted

Because of this configuration they are absolutely insane when under boost.

David,

Would u explain further why that is?

[Fully Vetted]

I believe it is because of two things. It's ability to rev so quickly due to less rotating mass and it's ability to evacuate its exhaust so efficiently. These things are nothing but giant air pumps. If you shove air in, especially under boost, you've got to get air out at the same rate or it robs power.

I did misspeak earlier. The 5.2 is not the Coyote engine. The Coyote engine is an 11:1 compression 5.0L yielding 435HP/390 lb ft of torque. The 5.2L FPC is the Voodoo engine that comes with 12:1 compression and yields 526HP at, wait for it...7500 RPM! With a redline of 8250! IMHO, this is the modern day LT5. A bean counters be damned engine that changes the rules and flips the bird to those that want to play on a level playing field. And the only car this engine is available in is a Shelby.

Here's a great article on the Voodoo engine:

http://www.powerperformancenews.com/...e/#prettyPhoto

[mgbrv8]

Here is some sound with some revs

https://www.facebook.com/holger.hove...2992382110799/

David Hetrick

[Fully Vetted]

Wow.

[LGAFF]

Should we start a "Show us your Crank" thread....oh, uh...maybe not

[Jagdpanzer]

Sure, here's my 4" Bryant

[LGAFF]

Not often you can brag about having a 4 inch crank

[mgbrv8]

Now that's funny.

Dave

Originally Posted by LGAFF

Not often you can brag about having a 4 inch crank