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View Full Version : OPOC gas engine claims 40% efficiency



chef
16 February 2011, 0047
Opposed Piston Opposed Cylinder Engine
http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder

Partway through the video I heard the German dude claim the OPOC engine is 40% efficient, roughly double that of traditional ICEs. They claim better waste heat management as one of the contributors to efficiency. I'm torn on developments like this. While it's great to see a major boost in fuel efficiency, the flip side is that it may take the public's eye off the ball -- getting ICEs off the streets. People may get lulled into a sense of complacency again and delay the inevitable depletion of oil and environmental damage.

The summary text is pasted below (it's difficult to read on the web page since it's crammed into a tiny box below the video).


"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."

If you watch through to the 2nd half, the poor kid being interviewed almost falls apart, again and again. :rolleyes:

Coninsan
16 February 2011, 0626
I've seen this ICE concept pop in and out of the publics eyes for years, along with the ball engine and cylindrically opposed engine.
40% efficiancy sounds pretty nice and the company is right to focus on high load operations; Trucks, Tanks, heavy equipment, places where Ev's still face alot of development to compete. If this engine is run on renewable sources, I can't see any problem in deploying them in the this sector.
But since the developers still say that there's years of development needed still before this engine can enter production, then it's to be viewed as vaporware IMO.

larryrose11
16 February 2011, 1137
Heavy load operations all use Diesel. The peak efficiency of over the road diesel is more like 40 - 45%, so, I dont see how this is better. Further, we allready have diesel runing on biofuel.
For over the road trucking, this 45% efficency region of engine operation is where they make the most NOX. Emissions is a BIG limitation of heavy trucking.

jazclrint
16 February 2011, 1554
The advantage I think EVs have is now that the EPA says 33.7kWh=1 gal of gas, we can say, look, the Tesla does 0-60 in under 4 seconds, and get 150mpg, and elmotos get 300+! Not to mention how little the maintenance costs are, how little time you'll spend getting to know the local mechanic, and how nice it is to just plug your gar in at home and save an extra 20 minutes+ on flubbing around at the gas station. After they see all that, 40% efficient gas engines will not be big news.

Richard230
16 February 2011, 1647
The advantage I think EVs have is now that the EPA says 33.7kWh=1 gal of gas, we can say, look, the Tesla does 0-60 in under 4 seconds, and get 150mpg, and elmotos get 300+! Not to mention how little the maintenance costs are, how little time you'll spend getting to know the local mechanic, and how nice it is to just plug your gar in at home and save an extra 20 minutes+ on flubbing around at the gas station. After they see all that, 40% efficient gas engines will not be big news.

I keep wondering how the lack of regular and expensive visits to your local motorcycle shop is going to affect their bottom line, should they start selling electric motorcycles. I figure that my BMW shop gets about half of their yearly revenue from the shop in the "backroom", which provides regular service that goes from around $500 and up for major (anything but an oil change) service.

I don't drive my car enough to get a feel for its auto servicing, but my daughter visits the Subaru dealer every 3,000 miles for service that costs at least $300 a pop. Most of that income will be lost by EV dealers. I wonder how they will make up the loss?

jazclrint
16 February 2011, 1938
I think some of it will be hikes in labor cost. To me, someone who can troubleshoot electricity and electronics is going to have more expensive skills and more academic training. Ok, I'll just blurt it out, but mind you this is a VAST over generalization. I feel that Electricians are smarter and required to be higher educated than Mechanics. You're gonna need nerds, and not red-necks that are mechanically inclined. They, are going to want to be paid more for their technical skills. So getting your bike fixed, when it actually has a major electrical problem, is gonna be expensive.

But Richard, I just had this thought. If they weren't paying hundreds of dollars once a year to get out valves adjusted (or just checked to find they are still in spec if you're VFR owner) and gas, would people be more willing to pay retail prices for consumables like tires and brakes instead of mail ordering them and trying to do them themselves? Also, the prices are up there with 600cc and 1000cc sport bikes, so couldn't it be looked at as making the net profit amount of a $10,000 bike for the performance of a $6000 bike. Profit margins will probably be the same though.

But you are right, it doesn't look like the profit from maintenance are there. But then again, you won't need the overhead and employees for maintenance either. You could have those guys installing solar panels and wind turbines. :D

chef
16 February 2011, 2036
Heavy load operations all use Diesel. The peak efficiency of over the road diesel is more like 40 - 45%, so, I dont see how this is better. Further, we allready have diesel runing on biofuel.
For over the road trucking, this 45% efficency region of engine operation is where they make the most NOX. Emissions is a BIG limitation of heavy trucking.

Maybe the OPOC engine has better emissions along with improved efficiency. It burns gas instead of diesel so maybe it can avoid some of those pollutants. Just speculating here.



I keep wondering how the lack of regular and expensive visits to your local motorcycle shop is going to affect their bottom line, should they start selling electric motorcycles. I figure that my BMW shop gets about half of their yearly revenue from the shop in the "backroom", which provides regular service that goes from around $500 and up for major (anything but an oil change) service.
Battery checkups & maintenance could generate service revenue. No battery, BMS or battery system will be perfect. Manufacturing defects are always a part of high volume production. Vehicle makers could require periodic battery checkups in order for the warranty to remain valid.
Now that I think about it, a cottage industry of battery refurbishers could do well.

There will still be a need for tire changes, fluid checkups for brakes, air conditioning...

But yeah overall the service shops may take a hit until they figure out new revenue streams.

chdfarl
16 February 2011, 2037
I Ok, I'll just blurt it out, but mind you this is a VAST over generalization. I feel that Electricians are smarter and required to be higher educated than Mechanics. You're gonna need nerds, and not red-necks that are mechanically inclined.

Thats a very ignorant generalization!

Richard230
17 February 2011, 0927
Just a comment about motorcycle servicing costs. (I happen to know a professional mechanic.) It is typical for motorcycle shops (at least around here) to sort of lease out their shop area and let their mechanics operate as independent contractors. Typical shop rates are around $100 per hour and the mechanic gets about $35 of that. The service billing is performed using the "flat-rate" system and if the mechanic can beat the flat-rate time, both he and the shop profits as the actual hourly rate goes up accordingly. The shop get the rest of the hourly rate for the space, insurance, specialized testing equipment, administration and overhead costs and the like. How much of their remaining 2/3rd ends up as profit I have no idea, but they don't make much from new bike sales, as profit margins are around $1000 per bike (it varies with the model and various factory promotions) and with most motorcycle shop sales averaging not much more than a few hundred a year, no one is getting rich selling motorcycles. And with motorcycles being a luxury in the US, you can really get hurt in a down economy - which is why so many dealers have gone out of business over the past couple of years. It is a risky business.

While I don't have any answers on how traditional motorcycle shops can make up the profits from reduced regular servicing that would not be needed by EV motorcycles, with gas prices rapidly going up, I think there is a good market for a practical commuter electric motorcycle that could boost new motorcycle sales, even if it doesn't create a lot of after-sales maintenance revenue.

I also agree that there will be a decent cottage industry opportunity for knowledgeable people to provide after-sales EV service, as this service will most likely need more education and knowledge and require less of the specialized factory-controlled equipment that is now required to fully service modern FI, IC motorcycles. This lack of factory-controlled equipment and connections, will allow people to set up servicing operations in their garages - or better yet, offer drive-by servicing that could be performed out of the back of a van. The opportunities are potentially huge, but I am not sure how many people currently have the knowledge and skills to provide this service and it might take a long time to build up this resource.

jazclrint
17 February 2011, 1857
Thats a very ignorant generalization!

Prejudiced, but I'll argue the ignorant. Ignorant would imply and uneducated statement. Using the Navy as an example, you have to be smarter (as in a higher ASVAB score) to be an airplane electrician than you do to be an aircraft engine mechanic. That is true across the board with any electrical vs. mechanical field in the Navy, and I'm sure with all the armed services. Now, you never know who you're going to get in the civilian world, so as far as I know you're a much better electrical troubleshooter than I am. But it does not change that many people who are or could be capable of regular motorcycle maintenance are not going to be capable of electric bike trouble shooting. If they were, Richard230's GPR-S would have been running a long time ago.

HighlanderMWC
17 February 2011, 1920
In many cases with a production bike I would imagine it would be easier for a mechanic to maintain than an ICE. As an example, my local Brammo tech was formerly a Harley mechanic. You would think it wouldn't take all that much to come up with simplistic bench tests for the various components of an electric bike and except for the battery aren't they all relatively inexpensive to simply replace? When it comes to troubleshooting I wouldn't say ICE mechanics really have much of a leg up -- I have a fuel flow problem on my VTX that they have never been able to resolve.

Sure Richard's GPRS is a counter example, but it seems that those bikes are not really designed as consumer products. Apparently there isn't much in it to protect the batteries from the rider (not implying Richard did anything wrong, but he does have a pretty extreme duty cycle with his hill and speed requirements and most likely the bike was pulling a much higher discharge rate than the batteries could safely handle).