Snakehead Shape Is the Secret to Power Stroke Success

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What's the secret to Ford's 2015 Power Stroke's horsepower and torque success? Apparently, according to a press release, it's the shape of the exhaust down pipe that has a vague resemblance to the head of a king cobra snake when it's ready to strike.

The new Power Stroke engine is the undisputed leader in the horsepower and torque war in the heavy-duty pickup truck segment, with a Society of Automotive Engineers-rated 440 hp and 860 pounds-feet of torque from the 6.7-liter compacted graphite V-8 block. Although there were many changes to the 2015 turbo-diesel, one of the biggest changes responsible for those big numbers came from the 90-degree bend at the turbo-exhaust outlet. This, the engineers tell us, is one of the biggest reasons the horsepower and torque numbers climbed so dramatically from the previous 400/800 ratings.

Whether this means we'll see more animal- or reptile-shaped engine parts from Ford remains to be seen. However, if advance fluid dynamics computer modeling theories indicate that such designs get more torque and fuel economy from turbo-diesel engines, we don't have a problem with an air cleaner box that looks like an armadillo.

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snakehead? Get outta here!

Looks more like an old radiator hose that's about to burst.

It doesn't make sense to me why this "cobra head" design would improve performance substantially.

I am no diesel guru, but I do know that for many years having any 90 degree bends in any part of the exhaust system has been a big no-no.

Maybe I am not up to date with the current technology, but I'm sure that I am not the only one confused by this.

Most likely, any performance improvements for the upcoming Powerstroke are due to a variety of factors and not a single aspect of design.

If it's really so easy to gain a big performance increase due to Ford's new downpipe shape, the competition could easily emulate it. Ford wouldn't give up their advantage so easily. I think this is more of a marketing thing than anything else.

In aviation we have much plumbing for ECS and bleed air systems and we do have 'squashed' elbows.

If you look at this logically the flattened elbows will keep the airflow more laminar. But the benefits aren't what Ford are suggesting.

Ford is having a wank.

It also appears at the widest point in the elbow the area is greater than the outlet at the turbo.

This is what is termed a diverging duct. This will increase pressure and temperature at the turbine.

Is this good?

It looks defective to me. Good job PR division.

To me it looks like a snake that has swallowed a rat!

@Big Al from Oz
Your assessment holds validity as you have experience from the aviation industry that most don't have.

The rest of us are left to guess about what designs will work and what won't.

What I do know is that the diesel pickup market in the US is one of the largest markets for aftermarket modification. Why? The OEMs don't seem to realize that their "designs" are often a major limitation of an engine's potential.

I therefore do not put much trust in specific designs that an OEM comes up with. After a year or two a truck being on the market, companies like Banks Power come along and create modifications like turbo setups that offer vast improvement over the original design.

What gets me is that a company like Ford is bringing in billions per year. These aftermarket companies come along that make a very small fraction of that and create modifications that best what the engineers designed.

Engineers like any group can get trapped in standard patterns of thought. The 'minimal bends" theory works fine with round tubing but they may of discovered that a flattened pipe bend works better in maintaining laminar flow and may aid in scavenging.

I'm sure the engineers have done their homework.

There has got to be a good reason why a flattened shape works better, because in the past, that same kind of flattened shape would have been very restrictive to a turbo.

I guess that turbos today are much different than from back when I had my diesel.

@HEMI MONSTER - I wonder how they discovered this design?

Some guy putting the engine in the dyno room made a mistake and squashed the pipe and no one noticed until after the dyno run ;)

This reminds me of the expansion chamber on 2 stroke dirt bikes.

The same concept it true for HVAC airflow, why would it be any different for an engine's intake system? Are people suggesting that corners have no effect?

This wouldn't have been restrictive in past turbo setups. Jet engines have been using much of this since the 1930s.

It's about the cost. The cost of efficiency gains in jet engines is pararmount, money is of less relavence.

Now with new and more stringent FE for motor vehicles, more so than emission regulations engine efficiency is becoming more cost effective.

To make that elbow in lieu of 'just and elbow' would have cost literally thousands of dollars in development.

These costs will be passed on.

As you've stated manufacturers don't invest enough into the development of vehicles.

Two weeks ago I installed a new suspension kit on my pickup. It is vastly superior to the OEM suspension. But looking at the physical differences it doesn't appear to be much.

But once you look inside of the shocks, metallurgy in the springs and the effort in tempering the springs you'll see the cost.

Mazda wouldn't have spent an additional $1 000 on the BT50 suspension. It makes them less competitive.

It seems sometimes close enough is good enough until a competitor is prepared to go that extra yard and create more competition.

But, it's amazing it has taken over 60 years for such a simple and known change to occur like this.

Sort of like all cars have drum brakes, then someone decides discs are better (which they are in most cases). Even the use of halogen for lights has been around for yonks and how long did it take the automotive industry to use it?

At least Mazda was able to measure a one dimensional line, ie suspension travel and not screw it up.

Situation::::FIAT RAM HEADQUARTERS, Detroit, 23rd October 2011::::::::

Ram Engineer. "Now is that 10.75" of travel? Let's look closer."

Ram Engineer's offsider. "Nah, who cares well make the an even 10", is easier to remember".

Ram Engineer. "What about that soft and luscious suspension we gave it. Wouldn't the suspension be more susceptible to an overload situation?"

Ram Engineer's offside. "Well if the shock absorber extension is shortened maybe no one will ever find out. We can use the shortened shock extension to stop excessive suspension travel".

Ram Engineer. " Geez, you are brilliant".

Ford has done it. They beat out the top dog Ram in horsepower and torque. Now they need to concentrate on frame and suspension on the next super duty. The target is always moving.
I give Ford credit for taking on their own diesel engine. Navistar was giving them a bad name in diesel trucks. Ford didn't have a lot of options. Time will tell if this new engine will be reliable. Seems to get the job done climbing while towing.

I feel sorry for O.E.M. Their hands are tied by the government price etc.. It is always easier to improve on a design rather than starting with a blank piece of paper. Which is what after market does.

This engine bay is ugly with all the lines going everywhere.

The diesel Torque and HP numbers for all three majors has reached the point that which brand has the most is not very relevant any more other than for bragging rights. All have far more than I'll ever need, even towing a 15,000+ pound fifthwheel around this beautiful country. They all do a great job. Now the selling points for me have to do with features and creature comforts, not with torque and horsepower.

@jrt, Considering these trucks are 70,000 plus. You are not alone wanting the total package. Comfort, capability, etc...
G.M. and Ram trucks are ahead of Ford in the total package. Ford has some more money to drop into the Super Duty to catch G.M. and Ram with better ride and better interior. That C-channel has got to go on these Ford H.D's.

Great original idea that snakehead downturn off the turbo. The 6.5 diesels in the GM trucks had them from 1992 to about 1997. Man, did they have POWER!

@HEMI V8 and JRT
I agree. There comes a point when the power some of these new diesel are making is completely unnecessary. You only need so much to get the job done, and while it is nice to know there is so much reserve potential, it would not be a selling point for me.

If I was in the market for a diesel truck, more than anything I would take reliability into consideration. Ford, GM and Ram all have to improve in this regard. Replacing injectors nowadays can easily cost $3-4k. A full engine replacement/overhaul can top $10k.

There is never a good time to have to deal with repairs and if a truck being used for recreation (as would be the case with me), having to deal with that much in repair costs hardly makes sense.

Anyways, I'm sure many people would agree with me, we can care less about how much "power" these diesels are producing. Start working on reliability.

"The Sierra 3500's greatest strengths is how well it performs when empty; in fact, it won both empty tests we ran at the Milan Dragway (the zero-to-60-mph and quarter-mile tests), as well as stopping the fastest when empty during our brake test at GM's Milford Proving Ground. Interestingly, the GMC was the our mileage champ when towing our heavy loads, winning the fuel economy test (with a 16,000-pound trailer in tow) in Michigan; we should also note that during our unofficial mpg calculation running from Las Vegas to Denver, the GMC (towing a 20,000-pound trailer) averaged about 10 mpg while the Ford and Ram hovered around 7 and 8 mpg, respectively."

Yep, Ford should be proud, the Duramax got 40 percent better FE@ Near Max Trailering over the Ford and also beat it unloaded 0-60 and 1/4, all with unproven engine on its second redesign in just a few years, pair that with pathetic warranty and we got a real winner on our hands.

with a Society of Automotive Engineers-rated 440 hp and 860 pounds-feet of torque from the 6.7-liter graphite composite V-8 block.

For a moment there I was wondering if its first of April today!

Graphite composite block!?

We have a fleet of 6.7's at work and they suck. Cab and chassis trucks are detuned to 300hp and 650 torque. Mine has 26000 miles on it and it has had the radiator replaced and water pump replaced and intake tube replaced twice, 2 different tunes have been downloaded. No power at all

@ HEMI V8 - the game of leap frog is never static. Ford has not made any comments as to whether or not the next gen trucks will have boxed frames. They most likely will keep C-channel for chassis cab trucks and have boxed frames of pickups with a box. Ram already does this.

@Chev what's your name.......

The PowerStroke block is made from Compacted graphite iron engine block or (CGI).

Probably a typo on their part.

Read through the Annexes.

It appears the Germans were the first to develop this form of cast iron in the 1950s.

It was first used on fast train disc brakes.

You are posting at the wrong thread. It doesn't make sense. What has Mazda to do with Ford snakes.

If c channel frames are good enough for the ram 4500-5500 and big rigs and all medium duty trucks I think its good enough for the Ford Super Duty.

@Diesel bob, I disagree.

I see it as an expansion chamber similar to the 2 stroke motorcycles.
All exhaust systems produce an acoustic wave in the opposite direction, you don't want that wave to travel back into the cylinder against the flow.
The expansion chamber is designed to control the acoustic wave.

Snake Head = Snake Oil ?

Boy do those Ford frames twist ! Shame they don't show the Ram as a comparison .... The Ram must have been similar to the Chevy truck, or better, because otherwise they would have shown them ....

The Cummings Diesel used in the Ram never needed modified or changed for over 10 years in use.
Tell me? How many different diesel engines did Ford go thru in the past 10 years?
Can't Ford make a decent diesel engine they can stick too?

Ford continues to be the leading in Stroking their customers and Milking them good.

Yes Ram had an 8 speed first, but they need it more and they bought theirs from ZF and just tweaked it a little. Their version did not go through all the validation testing GM has put their through or that the 10 speed will go through. GM started to cut back on this in the 80′s and they had failures. Now they are back to the testing they used to do and we will not have failure like in the past.

Note Ram has had recalls and failures with their ZF box.

Tom3, you have a very selective memory

2001 - changed from the 6.5 to the 6.6 Duramax LB7
2004 - changed from the LB7 to the LLY
2005 - released a second version of the LLY
2006 - released the LBZ
2007 - released the LMM
2011 - released the LML
2016 - will change again.

Total 7 significant changes since 2001

I am not as familiar with the years, but they changed from the 12 valve to the 24 valve 5.9 ISB
Then there was a common rail version of the 5.9
Then there was the 6.7
Then there was the DEF update
There will be changes for 2016

So about 5 changes over a similar time period

Ford had the 7.3 and changed to the 6.0 in 2003
6.4 in 2008
6.7 in 2011
6.7 v2 in 2015

4 changes!

I suppose you thought that if the displacement doesn't change, then it doesn't count. A fool would think that.

Alex please learn

Johnny Doe, at least make a point, rather than just copy and paste a link. Is there a point you are trying to make?

because a frame flexs its no good? do a twist ditch test with a ram 4500 and it'll do the same as ford super duty frame and flex or even do the twist ditch test with a kodiak and it'll flex too. If boxed frames were so great then why doesn't ram use it on their 4500 5500? You want SOME flex. There is a difference between flexing and bending.

You also have a selective memory back in 2007-2008 Ford was talking about a 4.4L V8 diesel for their F-150.
Tell me ? Do you know why it never happened?
I do! The new crop of engineers were working on the 2011 Eco-Boost thinking it was the better way to go, but that was a flop cause it never got the gas mileage they wanted, so they redesigned the 2009 F-150 by getting rid of the heavy frame and adding a 6 speed transmission that never worked! In 2011 they did away with the reliable 5.4 engine and figured the Eco-Boost would save the day!
Ford would be better off today if they kept the 2004-2008 design and use either a diesel or keep the 5.4 with engine deactivation.
So in 2015 they will cheapen it more making it 700 lbs lighter and going with the same mistake with a smaller eco-boost while at the same time Chevy makes the same V8 that gets BETTER gas mileage and Ram has a 3.0 Diesel that gets 30 MPG.
Ford keeps changing to cover up its past mistakes!

Yes Alex the heads change once, added emissions, and added strength to the block. Other then that just computer flashes, so not a total of 7 big changes you speak of. If you want to count computer flashes you should add the 6.7Ls job two flash and the changes they did to the 6.0L.

Tom, the Ford 4.4 and Chevy 4.5 have nothing to do with the point of heavy duty engine upgrades. They were prototypes for new engines, not to replace the larger ones, but to offer additionally. No I don't have selective memory. The EcoBoost has peak torque @ 2500 rpm, the Chevy has less torque and it peaks at 4,100 rpm! So you got a torqueless small V8 with an overdriven 3.08:1 axle ratio. The fuel economy is the same as the EcoBoost but with lower performance. How in any logical way, do you call that good for the Chevy? The only Chevy I would buy is a Duramax with the Allison (I hate the TH trannies). The Ram 1500 EcoDiesel would be ok if I a $50,000 truck with a 9,000 towing limit was acceptable to me. But it isn't.
Like I said Tom, Chevy has changed the Duramax more times than Ford has changed the Power Stroke, so I guess that means Chevy is covering up its past mistakes by your own twisted logic. Stop being a blind fanboi!

The only upgrade that may have been a computer flash was the LLY2 to LBZ. So 6 upgrades then. That's a good thing, I am not attacking the fact, I am just pointing it out because it is a fact. I actually like the fact they upgrade their technology frequently.

@Tom#3 - Alex is correct.

The Cummins I-6 has go through various evolutions. Fans of the engine will even go as far as to tell you which blocks are tougher for mods and which ones are prone to failure. IIRC there was a batch made in Mexico using very dense strong alloys and is the best block for durability stock or modded. They even had some made in Brazil that were crap.

Ford chose to go with the ecoboost line of engines because it was a cheaper option for them and consumers when compared to diesels. The EB line is easier to adapt to multiple platforms. That also makes it a cheaper option due to amortization of costs.

@JohnnieDoe - even the Duramax has gone through evolutionary changes.

Ford just happened to have to diesel change engines. The original IH based PowerStroke had to get replaced because it was easier and cheaper to go with a new engine then make the old on meet emissions. The 6.0 didn't have enough head bolts and was prone to failure when modded. The 6.4 was infamous for being hard on fuel but so were any diesel of this era new to particulate filters and regen cycles.

And who did Cummins work with to deliver the I-6?

The Italians. Back when the inline 6 Cummins was being made Fiat was the world leader in diesel technology.

The Italian version of this engine is still being produced.

Technology transfer. You see a lot of this in the automotive world.


Ford had the 6.9 and 7.3 turbo and non turbo 7.3
Before the power stroke they went thru more design changes than cummins and def for the cummins was software change not internal engine change same engine just add on emissions
Just sayin

@Cummins man - when one looks at the issues Ford had with International it is obvious who is better at designing diesels. Cummins easily beats IH. That is why we see Cummins in multiple applications and IH only in their stuff.

The headline for this story is dreadfully misleading... should say "Gimmicky Technology In Real World Testing Still Cant Beat 11 year old Engine with over 100ftlbs less torque"

@devilsadvocate - if one looks at the performance aspect of the HD Diesel Challenge, the Ford beat the GM truck in every performance test except empty times. Even with the empty runs the times between the 2 were negligible.

Those stats indicate that the 6.7 PowerStroke does beat the Duramax.

The reason why the Ford lost was due an outdated chassis and interior.

GM was superior in those areas. That is why it dearned the win.

@Cummins Man, I wasn't going that far back, but ok... Dodge had a 6BT before the ISB and added an intercooler at some point to the 12 valve.

GM had a non-turbo 6.5 before the turbo version, and a smaller 6.2 before that.

Yep, Ford had a 6.9 and a 7.3 IDI engines prior to the Power Stroke in 1995 I think.

As I said, development/progress is a good thing for technology. Can you imagine if today's trucks use 20-yr old technology?

@Alex - we still see engines with pushrods ;)

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