Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

Register Log in
  • Congratulations waross on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Ford going to opposed piston engine in Ford F150 1

Status
Not open for further replies.
My Bad,
The story was a re issue of a story that came out in January.
B.E.

You are judged not by what you know, but by what you can do.
 
Probably not all it is cracked up to be, either. Having that piston arrangement doesn't magically solve anything and it certainly introduces a lot of its own headaches.
 
Double knocker engines. Great to see 1950s technology being revisited. Quick thought experiment, how much of the combustion chamber's heat energy is lost in the cylinder head? or via the piston?

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
The Commer Knocker (and Fairbanks Morse) opposing piston engines were built decades ago. They did not take over the market then. What, fundamentally, is different now? Physics hasn't changed ...
 
Greg ,
Double knocker 1950s how about 1930s The Junkers Jumo 204 looks a lot like the ford engine.
B.E.

You are judged not by what you know, but by what you can do.
 
Brian; One thing that has changed is stringent exhaust emission regulations - it is hard enough to meet current regulations cost effectively with 4-stroke engines, and harder still with side injection piston-ported 2-stroke combustion systems. I am not saying that it can't be done, but to reach these levels, the industry as a whole had to concentrate on one approach and make it work. 4-valve central injector 4-stroke combustion systems looked like an easier mountain to climb at the time.

PJGD
 
Physics may not have changed, but technology enablers (notably material science and electronic control) have. A good but impossible idea may now be a good and possible idea. Nothing's new, but some things are becoming practical.

Steve
 
Some of the experts here should let the Army know it's wasting the $47.4 million they awarded to Cummins and Achates.

"Cummins Inc. has landed a $47.4 million contract from the National Advanced Mobility Consortium to develop a revolutionary new type of diesel engine for the U.S. Army that promises to be lighter and more efficient than those currently in use. The Advanced Combat Engine (ACE) project is a joint venture between Cummins and California-based Achates Power, who has designed an opposed-piston engine that works on a two-stroke combustion cycle and eliminates the need for a valvetrain."

Physics haven't changed, but material science, design refinement technology (.e. CFD), and adaptive control sure have.
 
The US Army also blew millions (back when millions was real money) on the adiabatic ceramic engine. Selling transformative pie in the sky to defence forces is like robbing a baby. It's other people's money, all the officers want is to be associated with a successful, preferably fun, project.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
I think that the fundimental problem of opposed piston two strokes is that the combustion chamber is of necessity the same diameter as the cylinder . this produces a problem of shape and admission of fuel from the side injectors . the exhaust piston is subject to much heat from combustion and exhaust flow . the engine is also not a natural overexpander like the Atkins cycle and relies entirely on a supercharger to run .

Link this one is an overexpander but I am not sure how much strain or load that crank mechanism can stand
Opposed piston fourstroke ?

A tidy mind not intelligent as it ignors the random opportunities of total chaos. Thats my excuse anyway
Malbeare
 
Greg, if they fooled anyone, it was Cummins (who put Achates under subcontract), and Cummins knows a bit about engines.
 
malbeare,

Achates published an SAE paper you might find interesting titled "Thermodynamic Benefits of Opposed-Piston Two Stroke Engines" available at
Quoting from the paper abstract, "The simulation results showed that combining the opposed-piston architecture with the two stroke cycle increased the indicated thermal efficiency through a combination of three effects: reduced heat transfer because the opposed-piston architecture creates a more favorable combustion chamber area/volume ratio, increased ratio of specific heats because of leaner operating conditions made possible by the two-stroke cycle, and decreased combustion duration achievable at the fixed maximum pressure rise rate because of the lower energy release density of the two-stroke engine. When averaged over a representative engine cycle, the opposed-piston two-stroke engine had 10.4% lower indicated-specific fuel consumption than the four-stroke engine."

On the other hand, EcoMotors was working a similar design but appears to have closed in January of this year. It's not clear why they closed down. It may have been because they encountered problems or because their investors pulled out due to Achates' overwhelming lead. See
Rod
 
This is stolen technology from Fairbanks Morse, they have been making this style engine for decades even into the now time. Also they have the most efficient diesel engine there is for the size. It looks to me like they (FM) have redesigned the dual crankshaft drive system from what it was, as well as a few other changes.
Unless this engine in the ford is made from CGI rather than what looks like Al, it will be a failure.
 
enginesrus said:
This is stolen technology from Fairbanks Morse, they have been making this style engine for decades even into the now time.
Click to expand...

Fairbanks Morse didn't invent the opposed-piston engine. Nor the opposed-piston two stroke engine, or the opposed-piston diesel.

 
"...let the Army know it's wasting the $47.4 million they awarded to Cummins and Achates."

'Appeal to Somebody-is-Spending-Money' arguments aren't very convincing. They're several logical steps below 'Appeal to Authority' arguments, which are already extremely unconvincing.

 
VE1BLL,

I was reacting to the out-of-hand dismissal of Achates' work by armchair quarterbacks. Healthy skepticism is always appropriate, but where in rank relative to "Appeal to Authority" do you place off-the-cuff dismissal? Cummins is a well known engine manufacturer, and they presumably reviewed the design and prototype data before selecting it. Does that mean they're right> Of course not. They're opinion is, however, likely to be rooted in better information and understanding than the armchair quarterbacks.

Ford isn't the first to evaluate Achates. DARPA, DOE, and the Army has reviewed and funded their work, and Fairbanks Morse (who know the engine well) are adopting Achates designs for their own use according to
There are challenges in opposed piston engines, but there are also benefits to the architecture. Time will tell if Achates has overcome those challenges and can deliver on the benefits.

Rod
 
I was merely pointing out that the US Army's track record with new engine designs shows little proof that it is a viable design. I said nothing about Achates current work, and asked a technical question which was directly relevant, which was ignored in favor of grandstanding.

Cheers

Greg Locock


New here? Try reading these, they might help FAQ731-376
 
I never said FM invented it or the diesel. The design is something that they have had for I'm guessing close to 80 years. I just don't think its right for Achates to be advertising themselves as the great founders of the design.
And out of all the other outfits to ever use that design FM has been the longest, and has established a great record of durability with it, when everyone else gave up with it. So funny that this design could be the one that saves the recip piston engine and moves it farther into the future, especially when everyone is and was giving up on the 2 cycle design.
 
Status
Not open for further replies.

Similar threads

T
  • Locked
  • Question
A completely new piston engine architecture
Replies
19
Views
10K
LionelHutz
LionelHutz
GregLocock
  • Locked
  • News
Opposed piston swashplate motor - INNengine
Replies
8
Views
581
SwinnyGG
SwinnyGG
L
  • Locked
  • Question
internal combustion engine stuck valves 1
2
Replies
27
Views
12K
TugboatEng
TugboatEng
Gbawn
  • Locked
  • Question
Diesel Engine Ratings.
Replies
5
Views
1K
LittleInch
LittleInch
Redcobra2401
  • Locked
  • Question
Side valve diesel engine 4
2
Replies
26
Views
2K
Redcobra2401
Redcobra2401

Part and Inventory Search

Sponsor

Back
Top Bottom