I don't see any performance advantage in the 3 valve over the 4 valve. Personally, I'd rather have a 4 valve Navigator than a 3 valve. 4 valve Navigators feel alot stronger than 3 valve F150s, IMO.

According to Ford the 3 valve heads are alot easier to machine than the 4 valves, the 3 valves are physically alot smaller than even the 2 valve heads much less the 4 valves and they are ligther. I still don't understand Ford's reasoning for making the 3 valve head when they already had the 4 valve. The 4 valve could have adopted variable cam timing and I'm sure it would have outperformed the 3 valve.

Since the 3 valve is taking the place of the 2 valve, Ford should come out with a 5 valve head with dual spark plugs, variable valve timing and direct injection. Ford has played with 5 valve heads on the mod motor before on the Tremor concept. That would be cool.

Since the 6.2/7.0 hurricanes are supposed to be coming out I guess Ford won't put much effort into any more hipo mod motors. 3 valves might be it.

 

I agree completely.
Compared to the 2001 Cobra 4v 4.6, the 3v has less HP because it doesn't rev as high. The 3v has slight torque advantage, and it gets it with regular unleaded where the 4-valve needs premium. I feel that makes the 3v a worthy competitor.
The 05 Mustang GT is also about 300 lbs heavier than the previos GT.
Here's Motortrend's test times for recent Mustangs
05 GT 3v 300 HP 0-60=5.1 1/4=13.6 @ 99.9
03 Mach 1 4v 305 HP 0-60=5.6 1/4=13.88@ 101.91
02 Bullett 2v 265 HP 0-60=5.6 1/4=14.07@ 97.9
99 GT 2v 260 HP 0-60=5.4 1/4=14.0 @ 100.2
Carand Driver's Tests
01 Cobra 4v 320 HP 0-60=4.8 1/4=13.5 @ 105
05 GT 0-60=5.2 1/4=13.8 @ 102
Previos GT 0-60=5.5 1/4=? @?
I think the 3v is the right choice for the Mustang and would be great in an F-150. The heads are the same as the 3v 5.4 heads, so it would seem that if they phased out the 2Vs it would help bring costs down. WXboy, why are you so negative towards the 3V's. 2/10's when adding 300lbs is not bad at all. 15% Power increase, and a 9% weight increase. As far as all 3 competitors trucks smoking the F-150, their motors have higher displacement, and are in much lighter trucks, so they should be faster. The F-150 is by no means slow or underpowered with the new 5.4. From what I've driven them, they feel stronger than the previous version, which I felt had more than enough get up and go. They're a heck of a lot quicker than my OHV 4.0 Ranger, which I also feel has more power than I really need. And the OHC 4.0 blows away the OHV, at least in late 90's Explorers. And in an 04 Ranger compared to my 93 with a chip, intake and exhaust. I'm all for OHC and 3v's/ cylinder.

 

Why are some people so sure that a 3 valve SOHC WITH variable valve timing is so much less "complicated" than a DOHC?

I'll be honest, I don't know that it is or isn't.........I'm only guessing that VVT is more complex.

It's all moot, it's already done, but I can't help thinking the current 4 valve system is bought and paid for and would only get better with time. The new 3 valve sends the aftermarket back to the drawing board.

Ford ALWAYS has done this in the past. It's a perfect example why chevy was/is so popular for buildups.

 

It'd be kind of neat to get the responsible Ford engineer in here for live chat and answer some of these questions once and for all .

 

You mean like the Supercharged 4.6 03-04 Cobra, to try and keep up with the N/A Vette?

 

You mean the supercharged 4.6L to keep up with the 6.0L? Or do you mean the 4 seater to keep up with the 2 seater?

 

You're right on the money. Ford doesn't have to but they are really making everything more powerful. Almost overkill. Reminds me of how Chevy used to be. Like the '03-'04 Cobras, the GT, the new Mustang GT, the new 3-valve truck engines, the upcoming Shelby Cobra Mustang(550 hp S/C 5.4)

 

Your question was answered before you asked it

4v means twice as many cams as 3v, which translates into smaller, and lighter heads. The 3v heads are actually smaller than the 2v heads, as was already stated in this thread. If VVT is going to be used no matter what the engine, then 3v is less complex than 4v. The point of the Mustang GT is to offer people the most affordable 300 HP on the market. I would expect 4v to be saved for the SVT or Shelby version, depending on what happens with the future of SVT, one where people are willing to shell out an extra $10k for something that really moves, but in the GT and F150, 3v is an excellent choice.

 

Excuse me??? Besides an FTE member, where did Ford EVER say that VVT would be used on the 4 valve?

I'm sorry for being redundant, but here it goes again; the CURRENT crop of 4 valve motors, be it 4.6 or 5.4 perform as well or BETTER than the BRAND NEW, and IMHO more complex VVT 3 valve motors.

I also "believe" it would have been cheaper as well as less complex to refine the 4 valve heads whose tooling costs have been bought and paid for for a long time now.

Again, it's moot. I still think the 4 valve minus VVT would serve as a cheaper AND LESS COMPLEX GT motor and maybe add the VVT to the 4 valve for higher output motors. It's not happening, I'm wrong. But I don't agree with the reasoning.

 

The 4v minus VVT still requires premium gas to be competitve with 3v with VVT. The need for premium gas is usually reserved for cars that are more expensive and for people that don't mind spending the extra $$$ on higher priced gas. By being able to use regular gass in the 3v, it leaves more room for the aftermarket for those who want to add a chip or tuner to squeeze some extra juice out of the engine. From what I have read here, the 3v 5.4's respond very well to Tuners, gaining an extra 20 HP or so, much better than what can be gained by say the Intech 4v 5.4, which has less torque to begin with. You're right about tooling costs and design costs. But if 3v is the direction that Ford has decided to take, then eventually those costs will be offset by the lower producion costs of the 3v. No I can't say with any certanty that VVT would be used in a 4v, but VVT is starting to become mainstream, so it is reasonable to assume that it would make it's way into a the 4v modulars. I agree that 4v performance could be made better than 3v, but not for the same price.

 

Yeah, it was kind of like reinventing the wheel. On the upside, the new Hurricanes will be DOHC according to Motor Trend.

I also believe the DOHC to be more efficient. Case in point, BMW vs. Mercedes. The X5 with the 4.8L gets 16 city/21 highway while the ML500 gets 14 city/17 highway. And the BMW is supposed to be the fastest SUV besides the porsche cayenne turbo.

 

I agree with most everything you've said save the last comment. With very simple(and cheaper) cam changes the 4 valve powerband can be moved up or down as well as its octane requirement. Witness both Toy and Nissan's DOHC 4 valves.

Your In-Tech comment is interesting because a previous poster had mentioned the 5.4 3 valve in the Navi uses premium and has only 10#'s more torque at a 1000 RPM HIGHER than the 4 valver. Again a simple cam change and another 1000 RPM and the 4 valve should school it!

Does anyone know how Ford's VVT works? Solenoid? Centrifugal? Dual lobe with follower changing lobes? Another fear I have is while AG is right about bolt on parts and electronics, the limit of a VVT will be reached sooner depending on the aftermarkets willingness to deal with Ford's ever changing designs.(read cam changes)

 

As I stated before, I am glad to see Ford be proactive with the 3v. And I am not downing their efforts, only questioning the logic behind it at this point.

Personally, I don't see the 4V being all that more complicated than the 3v. The durability of the 4v has been proven. So really what difference does it make if you have a few more parts.

OR another way to look at it, no one is debating the point that the 3v head is more complicated than the 2v. If you really think about it, I am sure Ford could have squeezed the power of the 3v out of the 2v. Then the heads would have been simpler yet.

If they slide the 4v over instead of messing with the 3v, maybe progress could have be made on something else... Maybe something like this larger ci. v-8 they are supposed to be developing.

 

I agree!!

Sorta of ironic that any Ford supporter is arguing less "complexity" is a better engine.

Sorta like the GM camp touting how the "simple" push rod motor is more better for the same reason.

 

I'm not proud, bragging rights are important to me. I love the fact the V10 is the top gasser(for now) and I hope the Hurricane puts the 1/2 tons there.

It sux when we have to make exuses to compensate; "You may have a stronger motor but my rear diff is much larger!!!"