An extremely lightweight opposed piston opposed cylinder (OPOC) engine has been developed under a Defense Advanced Research Projects Agency (DARPA) program. FEV and Advanced Propulsion Technologies (APT) were asked by the U.S. Army Tank Automotive Research Development and Engineering Center (TARDEC) to modify this engine for heavy-truck applications. Analyzing the two stroke scavenging, the side-injection combustion, and the structure of the key components shows the potential of the OPOC concept. It is predicted for the 465 kW (650 hp) OPOC truck engine. The OPOC engine was designed to be modular. Each module is self-contained and delivers 325 hp. The modules are connected together via the Modular Displacement Clutch, which synchronizes the modules for achieving even firing when both modules are functioning. With an optimized scavenging process, the special design features of the OPOC engine offer a significant step towards the potential of the two-stroke engine having double the power density of a four-stroke engine. An estimated 90% scavenging efficiency has been achieved with unique gas exchange characteristics of the OPOC engine and the use of an electric assisted turbocharger. The OPOC engine runs with almost two times the engine speed (3800 rpm) along with a large cylinder stroke (167.53 mm), as a result of the split stroke of the opposed piston structure. This also improves the power density by another factor of 2.
Philleep commented on December 16, 2013
I am not an engineer, I do concept designs. One concept I have is for a small three wheel truck, simular to some they use to have in Germany. The truck is 55 inches high, and 11 feet long, it has a short bed and carries two people, and there is not room enough for an engine in front, but would have to go just behind the seat. The vehicle needs an engine that is quite flat, so that it would not protude to far into the bed area. An engine of about 10 to 20 horsepower would be sufficent for this type of truck. A small OPOC type engine might be ideal for such a vehicle. I have a question, however, will this engine smoke badly? Remember those DKW's how badly they smoked, they where two-stroke.
Nprimelimited commented on October 17, 2013
Seems like the modern day Doxford Engine. Percy Jackson would have been proud. I sailed on one in the 80's but the ship was 30 years old then,
jrtcomp commented on September 11, 2013
Same old, same old - Dr. Marius Paul the 1990's - early 2000's - the cylinder pressures were astronomical!
DC1 commented on November 15, 2011
This seems like a very complex way to add controlled exhaust valving to a two stroke engine. Wouldn't conventional poppet exhaust valves be much lighter, more compact,less expensive and a proven technology? An opposed two stroke with poppets would be as well balanced and works fine with crankcase pressurizing or turbocharging.
Also, why does this need to be a boxer motor if each side is inherently balanced by its two piston configuration? A single cylinder would work fine, and adding cylinders in an in-line fashion would be more compact, make intake, exhaust and fuel delivery routing simpler, and allow much more latitude in installation configurations.
The TS3, while remarkable, paid a huge weight and size penalty in drive train configuration. Does sound good though.
voyager commented on November 07, 2011
Love the principle and its basic simplicity. But why is there still no viable production engine after all those years of developing? Napier already had a triangle OPOC engine some 60 years ago. I am looking for a new type of ICE that will turn heads the same way my vehicle concept (check out newisetta.com) already does!
todd sculley commented on August 30, 2011
my name todd sculley . i have the test engine for the deltic p1500 engine and blue prints for sale contact me at firstname.lastname@example.org for any questions
darrenpowell commented on August 15, 2011
Search for the Gobron Brillie Engine from the first decade of the 20th Century and check out Hugo Junkers Engine of the same design (scroll down and have a look) - http://forums.tomm.com.au/index.php?topic=142.15 ... these things have been powering cars and aircraft almost a century ago so why does OPOC still have to go 'a long way to make it perfect'? How did OPOC get a patent on this?
Karlo commented on July 28, 2011
Es tut einfach weh zu sehen, wie Ingenieure gute, alte Grundgedanken, wie 2-Takt-Gegenkolben, in ein schlechtes Kleid (Steuerung, zu viele Einzelteile, schlechtes Design) stecken und außerdem dafür belohnt werden. Da habe ich selbst eine viel bessere Lösung.
ronson569 commented on July 15, 2011
How long before it is bought up by the oil industry or the government like all the other inventions that get great mileage. then will disappear.
John99 commented on July 07, 2011
Rootes in the UK made the TS3, the most successful opposed piston, 3 cylinder, one crankshaft, 2-stroke diesel engine ever. It was made for 18 years and discontinued in 1972 when US Chrysler bought Rootes and dropped it to sell their own range (vested interest). It was phenomenal in mpg, physical size and power/weight ratio. It was dropped just before the oil crisis otherwise it may have still been with us. The 4 cylinder TS4 was tested and was planned to go into the Commer/Dodge Commander truck. Chrysler ordered the prototypes destroyed. The engineers hid some. One has been rebuilt in NZ and is to go in a Commer truck. http://www.commer.org.nz/Commer_Connections/TS4Mtr.html. Type in "TS3" in Youtube to see the TS3 - lots there. Wonderful sound. http://www.youtube.com/watch?v=m5xOA53YX4s
A narrow V engine with two cylinders connected via a small tube and the pistons reaching TDC at the same time will give the same effect and both operating on the same crank as per normal.
The TS3 was the finest auto diesel engine ever made.