[[email protected]]

from a sheer power output perspective, it absolutely makes my point a valid one....exactly what progression of technology? just because it has variable cam timing? if you lock the timing of the camshafts to the upper RPM range (for sheer high-RPM power output), then there isnt much more to the newer engine---it has tremendous volumetric efficiency (> 100%)....that can't be done with a dedicated intake/exhaust manifold and custom camshafts on an older modular engine?? sure it can!......just takes time, money, and knowledge....the 2011 runs nearly 11:1 compression....that can't be done on an older mod motor? sure it can!...the 2011 runs oil squirters aimed at the bottom of the pistons for cooling......yes that helps, but the Cobra R didnt have them, it it made tons of power without them, and there are other things like coated piston tops and alcohol injection kits that can curb intake charge temperature upon the compression cycle.....the 2011 motor has a bigger bore, helping unshroud the intake valves....cant be done on a mod motor?....sure it can!...its called a big-bore "4.6", aka 5.0L mod motor

my point being that the overall design of an engine takes precidence....a well planned out (and dedicated) big-bore "4.6" 4V can make more power than the mighty Cobra R DOHC 5.4, without the hassles of installing the taller-decked 5.4 into the cramped up MN12 engine bay

one big thing the 2011 has is direct injection.

 

[kdanner]

one big thing the 2011 has is direct injection.

No, it certainly does not.

 

[kdanner]

Look at the 03/4 Cobra and compare it to the GT500...the main noticeable difference...displacement.

Couldn't disagree more. In a positive displacement blower combination, it's all about the blower. So displacement yes, but blower displacement, not engine displacement.

 

[[email protected]]

No, it certainly does not.

wait it's not direct injected?

Edit: i guess your right i was thinking of the V6.

 

[rotyp]

*Grabs a bag of popcorn*

This is a good movie!

 

[BIG PETE]

It never fails, where there are 5.4 powered cougars you are sure to get a cat fight.
Alan

Except at the track.

Pete

 

[guitar maestro]

but why didn't they do it on the R?

again, it all depends on capital....even ford didnt want to do a big-bore to a 5.4...why? ask them

and why not do all that to a 5.4? again, available capital.....i'd be willing to bet there's only a handful of people here with the capital to be sporting a big-bore 5.4 (which is around 5.8L), let alone to do all other "mods" (which sounds cheaper than it really is) that you can with a 4.6 big-bore (5.0L)....and there's even probably less who have the required knowledge I'd bet

 

[Nitemare]

Big bore 5.4 requires an aluminum block, correct? That alone would probably be out of most people's price range.

 

[guitar maestro]

Big bore 5.4 requires an aluminum block, correct? That alone would probably be out of most people's price range.

my point exactly......a far cry from fab'ing up a CAI for a 94/95, wouldntcha say?

 

[twin turbo 281]

some have also destroked the 5.4 to 300 cubes? big bore destroked 5.4 might be fun

 

[guitar maestro]

some have also destroked the 5.4 to 300 cubes? big bore destroked 5.4 might be fun

yada yada yada, no one here is gonna do it...and i'll eat my words the day they do...lol

 

[Grog6]

the day I acquire a GT supercar aluminum block

Before they closed, KarKraft had a Supercar engine for sale...

For the low, low price of 38k, lol.

Buy that, stuff it into an MN12; Now that's a fraking dream worth having!

I would cut and paste a k-member/frame to make that work; hell, if you didn't replace the k-member and other parts with some extremely solid bracing, the car would tear itself apart! (think twisting-body mustang, with a longer wheelbase to twist...)

But, of course; reality always intervenes with a good dream.

Alas, that engine's not what these guys are talking about at all; it's a stock 5.4 boat anchor... I mean, truck motor.

Nice dream, tho, GM! I'd love to build that car. (Obviously, if money and time were no object...)

Me personally, I'll stick with my PI and (longer term) DOHC plans.

 

[TGJ]

Your last line also stands true. Of course a well thought out 4.6 can make more power than the 5.4R...but do the same mods to that 5.4, and see the power it makes.

A well thought out similar 5.4 2V or 5.4 3V will NOT equal a well thought 4.6 2V or 4.6 3V in Natural Aspiration form. A lot of talk about how it will but none yet have come close. For the 5.4 to outshine the 4.6, it needs the 4V heads in N/A form.

A well thought out 5.0L Big-Bore 4.6L will out do any well thought out 5.4L with any head combination. The 5.0L Cammer from Ford with less parts made more than the 5.4 Cobra R did.

If you want a bigger displaced engine, the Big-Bore is the only way to go.

Except at the track.

Pete

Them 5.4's are afraid of the track.

 

[guitar maestro]

Me personally, I'll stick with my PI and (longer term) DOHC plans.

me too!...thats what my extra teksid block is for!

 

[Tbird1997]

good info on this thread... but im still kinda confused on why the 4.6 2v is better than the 5.4 2v... no ones really said why the 4.6 is better... other than is somewhat cheaper

 

[TGJ]

good info on this thread... but im still kinda confused on why the 4.6 2v is better than the 5.4 2v... no ones really said why the 4.6 is better... other than is somewhat cheaper

Been covered just about everytime the 5.4 comes up. To put it briefly. The 5.4 is considerably heavier. There is no power gain with a 5.4. The 5.4 makes more low end power but runs out of breath quickly and cannot make the same high rpm power than the 4.6 can. That is with the best 2V and 3V heads out there. The best 4V stuff, the 5.4 can out produce the 4.6. The Big-Bores unshroud the valves and can make better use of the air flowed by the heads and will out produce any equal 5.4 combo...

 

[Tbird1997]

thanks for clearing that up

 

[J.Miller]

In the T-Bird world that opinion is a theory and is not based on anything but here say and assumptions from a 99 swap with almost stock 99 4.6L components. 4.6L cams, heads, intake and etc. The weight difference is only 50Lbs. The picture could be different with 5.4L specific components.

The debate goes back and forth. There were only what 2-4 swaps tried and half of them never bothered posting information because they did not want to get involved in the debate. To date, no one has tried the swap in a long long time and with the age of these cars I doubt it is going to happen. :tongue:

 

[TGJ]

In the T-Bird world that opinion is a theory and is not based on anything but here say and assumptions from a 99 swap with almost stock 99 4.6L components. 4.6L cams, heads, intake and etc. The weight difference is only 50Lbs. The picture could be different with 5.4L specific components.

The debate goes back and forth. There were only what 2-4 swaps tried and half of them never bothered posting information because they did not want to get involved in the debate. To date, no one has tried the swap in a long long time and with the age of these cars I doubt it is going to happen. :tongue:

J.Miller's quit living a damn dream world. Quit posting your BS. Take your car to the track and run it. Prove to the world the 5.4 is worth and until you do all you post is BS.

I have paid attention to the Mustang swaps. No N/A 5.4 2V swap even in a 5 spd Mustang has broke the 300 RWHP mark. Flirting with it but not broken. The 4.6 2V in N/A form have achieved 340 in full street trim.

 

[JeffTBird93]

The 5.4 makes more low end power but runs out of breath quickly and cannot make the same high rpm power than the 4.6 can.

What's the reason for this? Just curious...