Went for a ride in a '11 today

Cobra Jay said:

One thing tho- IF, IF the 3v design is so great, or equal- how come the Shelby GT500 is a 4v, and we also make a 3v 5.4 truck engine?

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Again....my comparison was between the previous 4.6L 4-valve engines and the current 4.6L 3-valve engine.

The Shelby GT500 uses a different head than the previous B, tumble port and C castings found on the 4.6L's. They do move more air (which I'm quite certain I've already recognized) than the previously aforementioned units and sports a larger intake volume that is better suited to the larger displacement 5.4L engine. Not denying their capability.

I am however glad that you brought up the 5.4L 3-valve truck engine. The '04-'08 5.4L 3-valve truck heads makes 300hp/365tq (320hp/390lbs ft/tq as of '09), yet the 5.4L DOHC 4-Valve engines used in the '99-'02 Lincolns (which utilized a head casting nearly identical to the "C-design") made no more horsepower and 10lbs ft/tq less than the 3-valves did (20 less horsepower and 25lbs ft/tq less than the '09-up) with the exact same displacement?

Better flowing head, lesser results. Again, peek flow figures don't tell the whole story.

So I'll say it again. I agree that the latest 4-valve production head castings utilized on the S197 powered 5.4L engines and those on the new 5.0L Ti VCT engine are of a superior design to the current 3-valve castings...as are the later 4.6L C-castings (although not by much) and special production heads like the ones on the 5.4L Cobra R and 4.6L FR500's

...but as far as over all comparison goes, the early 4.6L 4-Valve B and Tumble Port heads are most certainly inferior to the current 3-valve and the later "C castings" hold a small advantage that seems only realized in the most serious circumstances (heavy engine modifications, or high boost applications).

This still doesn't take away from the fact that the 3-valve engine itself is a wildly successful (and every bit as capable) effort from Ford, for both the novice and aftermarket to build on. Fords need to jump up the displacement was no secret and has been frustrating Mustang enthusiasts for over 10-years now, but the fact remains that the power output and efficiency of their latest effort is amongst the best that the 4.6L had to offer. Combine that with its large production volume and huge aftermarket support and there’s no denying it’s been a big success. Even with the new 5.0L looming overhead in the next year or so.

Cobra Jay said:

Inappropriate Remark :ZipIt:

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There's no need for the poor attitude, or the snide remarks. I’ll debate with you, but I’m not getting into a pissing match. Play nice, or not at all please. This thread just seemed to get back on track, there’s no need to ruin it with more nonsense.