With all the buzz going around the ecoboost and people arguing you don't need motor displacement for power, I just realized something this morning. If displacement doesn't matter then why did Ford go from, in diesel, 7.3 to 6.0 to 6.4 to 6.7 and in gas 5.4 to 6.2? Seems like its playing a role again. Yes the ecoboost is putting out great power with a smaller power plant. But the big trucks aren't using this, just the little brother.

 

I see what you're saying but I'm not sure I can fully agree. I know your'e talking about new engines but just some comparisons:

460ci v8 = 250hp
3v 5.4 330ci v8 = 320hp
3v 6.8 413ci v10 = 362hp
6.2 379ci v8 = 385hp

Point being technology can make more with less. All of the newer engines have less CI but also make alot more hp and get better fuel economy than the old powerhouse 460. Sure they could make a 460ci today, and it would probably make 500+hp, but it wouldn't have the fuel economy the 6.2 does.

As for the switch to the 6.2 - they only wanted one gas engine, the 6.2 falls right between the 5.4 and the 6.8...w/ better hp than both of them. Granted it doesn't quite have the torque the 6.8 does.

The 6.7? Brand new in house design and they wanted to distance themselves after the problematic International 6.0 and 6.4's, and probably the key reason: they wanted to beat everyone else on hp/torque war to have bragging rights.

 

I was referring to the new engines. Regardless of how you look at it they've gone up in size since the super duty's inception besides the 7.3 to 6.0. I also understand For wanted one gas engine. It still went up in size from the other V8. V10 is its own animal and I think can be a direct comparison to the V8. And for the international motors, and the in house ford diesel for that matter, to make more power it looks as the increased displacement was part of the equation.

 

I meant the V10 cannot be a comparison to the V8. The extra 49ci over the 5.4 must be helping the 6.2 make 65 more HP.

 

Someone answer this for me. I am not an expert in regard to combustion engines. However, I have never bought the idea that a V6 will ever hold up under the same "working" conditions of a V8.

It seems to me that it is a physical impossibility. To me "torque" is the issue. A V6 pulling an identical work load of a V8 simply must do so with greater torque force on the pistons, rods, crankshaft etc. Also, it simply seems likely that the V6 will have to pull more RPMs to handle the same work load compared to a V8. Isn't torque and RPMs the killer of engines and drivetrains?

Back in the early 2000s I pulled a boat on a trailer with the combined weight in the 6,000 pound range. I pulled it with a V8 Chevy pickup. When I went shopping for a new pickup I had Ford/Chevy folks telling me I should consider a V6. They all told me that their V6s would handle the job just fine.

I rejected this idea as I wasn't just interested in whether the V6 would pull it, but at what cost to me in engine life etc. It has just never made any sense to me. So, my sense tells me that yes these V6s with all that horsepower are fine for people who want to drive them to and from work with maybe working them a little with a small trailer.

However, I would never buy one if I were going to work one very hard. It just seems to me that putting the V6 under the extreme limits will way more quickly destroy the engine. Consistently high torque and RPMs will break the engine down.

So, my thought is why the need for a high horsepower V6 when a V8 of lower horsepower will do a larger work load with less wear and tear on the engine.

I have argued this point with lots of people who pull travel trailers. Most people are willing to try to save money on the vehicle pulling the load while spending more on the size of the travel trailer and subsequent weight. They seem to think that any engine that will pull the load is ok. I keep arguing that MPG suffers and when you put the engine and drivetrain under extreme work loads you will pay by slowly killing the engine etc.

Just curious what some of you might think.

 

Obviously CI is part of the hp equation, but it's not all of it. I mean a 351 obviously has more power than a 2ci chainsaw. With fuel prices this high and not likely to drop anytime soon, engineers have a lot more to balance than they did before. In the old days you just added CI's to get more power - cheap and easy. Unfortunately w/ the EPA and higher fuel prices today, but people still demanding the same power, it's no longer that simple. Along w/ adding CI's comes other problems such as emissions and fuel economy that have to be addressed. As technology gets better, it becomes easier to add power while keeping the other things in check - yes CI will always be part of the equation but I for one see the trend starting to reverse or at least stay about the same for the time being. Case in point, the ecoboost - not saying that should be or ever will be in a SD but you can bet it's on Ford's mind.

Agreed, it's a different animal - I was only pointing out that even though it had less CI, it still made more hp than the 460. Which goes back to the hp equation - # of cylinders has an effect as well.

 

Welcome to FTE.

Try telling this to the Dodge forum guys.

I do agree with what you are saying for the most part.

 

Remember - torque GETS you going..... HP KEEPS you going.

 

In a gas engine of comparable sizes I agree w/ you (which is why I'm not in favor of an ecoboost in current form in a SD). However, in and of itself a v6 or any 6cyl for that matter isn't necessarily inferior to an 8. Case in point, the large industrial diesel engines - detroit for example has many v block engines. And like Miller pointed out, what about the cummins inline 6? It competes extremely well against the v8 powerstrokes.

Look at it this way, if a v6 had a larger bore and stroke than a v8, is it still "weaker"?

 

Ok, I can see what you are saying. Say you accelerate from a dead stop on a level surface. You reach a speed of 60 MPH and then begin a climb over the top of long hill/mountain and you try to maintain the same speed. In this instance is not climbing the hill and maintaining the same MPH at 60 not creating additional torque? Does it not require a higher RPM to maintain the same speed?

When I pull my travel trailer I hardly ever have the luxury of a flat surface, unless I am traveling across the US on I-40, especially across Arkansas, Oklahoma, Texas, New Mexico and Arizona.

What is the difference between a V6 and V8 in this scenario? Are the engines being stressed at the same level? Again my sense tells me no, but admittedly I am not very technical when it comes to engines etc.

 

[quote=maverick22;12130172Look at it this way, if a v6 had a larger bore and stroke than a v8, is it still "weaker"?[/quote]

I think what I have quoted from you is what bothers me about the V6s in regard to engine/drivetrain life.

I readily admit, it is the physics of the issue that I am hung up on. I can't seem to get past the idea that two engines of equal displacement [everything else being equal], the one with the two extra cylinders will be the last one standing assuming they are doing the same amount of work. And, I can't get past the idea that the reason for that is the less torgue [force] on the individual pistons, rods etc.

Anyway thanks for the responses.

 

When you think about an engines ability to handle power, especially a v6 or even a 4 cyl. You need to look at the durability of the internal components. They make 4 cylinders producing 300bhp now a days. Those are 300 reliable horses. Those engines are able to run 200k miles if properly maintained. If the internals on the ecoboost v6 are strong enough, the engine will last just as long as a v8. Look at 6cyl. Cummins.

 

A turbo'd v6 would not need to rev any higher than a v8 to maintain speed. It may need less revs in fact.

 

Yes, the Ecoboost does need less rpm than a V-8 produce the same power. The best way I can describe it is the Ecoboost is a diesel that runs on gas. The Ecoboost has the same power band and feel as a diesel (not saying they are as powerful as a diesel, just the characteristics are the same). Where a naturally aspirated gas has to rev from 3500 to 4500 rpm to pull a hill good when loaded, the Ecoboost only has to rev from 2000 to 3000 rpm.

 

Call me crazy but I will not buy a new Ford truck until they come out with a gasoline engine bigger than my V10-6.8 liters. I too am a fan of more cubes to make the work easier. The way it looks now, I will have my truck for a long time.