PDA

View Full Version : new 2 stroke



SkyPirate
09-25-2011, 07:57 AM
I didnt look into this to see how much itweighed or the actual dimensions but :



This is no wimp engine.
It's a two cylinder with four pistons delivering 300+ Horse Power
It's extremely small and very efficient and is presently in use in test applications
The configuration below is equivalent to a extremely ballsy four cylinder engine
When doubled, it's an extremely ballsy 600+ H.P. engine





http://images.hemmings.com/wp-content/uploads/2011/01/OPOC_600.jpg
It’s called OPOC (Opposed Piston Opposed Cylinder), and it’s a turbocharged two-stroke, two-cylinder, with four pistons, two in each cylinder, that will run on gasoline, diesel or ethanol. The two pistons, inside a single cylinder, pump toward and away from each other, thus allowing a cycle to be completed twice as quickly as a conventional engine while balancing it's own loads.
The heavy lifting for this unconventional concept was performed Prof. Peter Hofbauer. During his 20 years at VW, Hofbauer headed up, among other things, development of VW’s first diesel engine and the VR6.
The OPOC has been in development for several years, and the company claims it’s 30 percent lighter, one quarter the size and achieves 50 percent better fuel economy than a conventional turbo diesel engine.
They’re predicting 100 MPG in a conventional car.



For a good demo, See:
http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder (http://www.engineeringtv.com/video/Opposed-Piston-Opposed-Cylinder)

SkyPirate
09-25-2011, 12:26 PM
right now the phase they are working thru for this motor it's too big for aircraft,..but i wonder how long it will be before it reduces it's size for compact cars,.which then opens the doors forexperimental aircraft

Esser
09-25-2011, 03:32 PM
Bill Gates actually has a lot of money invested in this engine too. I have been watching it for a couple years. It looks promising. Especially if it runs on diesel which I have a love affair with. I think diesel is the future of av fuels especially since you can run JetA1 in the which is available not to mention water doesnt effect it as much, more torque(Super crusie props anyone?), and had more btus of engery per volume.

SkyPirate
09-25-2011, 05:12 PM
I guess with Bill Gates investing in it there is no lack of funds ,..and we might see a smaller version quicker ,..as for jet fuel ,..thats ok if your not going to let it set long,..say over a week unless you put Prist or an equivelant in it first,..have you ever took a glass of jet fuel and set it in a window? come back in a week and there will be things growing in it lol.

Mnflyer
09-25-2011, 06:11 PM
That engine configuration has been tried in the past as a 4 stroke with alot of hipe and nothing much ever came of it. So it will be interesting to see if it develops into a viable power source.
As for diesel fuel its not any more the future fuel than CNG is as Sky posted bugs readily grow in it and if Prist isn't used they will completely clog a filter caucusing a very quiet engine. Also be aware that JetA is Q grade kerosene so a diesel engine injector pump will require some modification or it will not be lubed AND Water most certainly has an effect on Jet Fuel and diesel why do you think all diesel vehicles have water drains.

Av8r3400
09-25-2011, 08:23 PM
Does your same logic apply to every airplane with a water drain on the fuel tank? Shall we go down the list of stuff (purposefully put) in your gasoline that will clog your filters? (At least Diesel or Jet A won't dissolve your gas tanks. :eek:)

Speaking as someone who has driven diesels (exclusively) for the last 20 years, I have NEVER had issue with water contamination or bacteria growth in my cars or trucks. Even after extended periods of sitting in the extreme variations of Wisconsin weather. I don't use treatments or any other type of snake oil, either.

Water is no more an issue for a diesel (compression ignition) than it is for a gasoline powered, spark ignition, engine. It won't burn. Period. Zero fun.

There are several compression ignition, reciprocating engines flying now that run on Jet A. Yes, lubrication mods are needed from a diesel injection pump, but they are flying none the less.



Compression ignition engines are far superior to sparkies in every operational parameter. The only reason you don't see more of them is the lack of motivation brought on by cheap gasoline and the moronic governmental regulations that (should be argued somewhere else...).

SkyPirate
09-25-2011, 09:02 PM
I drove truck for quite a few years too ,.macks and intersnatchalls with the good ole cummins in them,.( actually built 3 mobile home toters). I have had a fuel line freeze up a time or two,..but never had any diesel go bad even after sitting for 6 months,.. when I was working at Biore field refueling the jets ,..there were issues with the jet fuel,so Prist was usually asked for by the pilots..moreso in the winter then the summer ,..and only if the plane sat for long periods with fuel in the tanks during summer

Esser
09-26-2011, 03:26 AM
Well if you are talking about water sitting in the bottom of your tank and it being injected into your engine yes of course you are right but diesel fuel is hygroscopic and can absorb watering to its molecular structure. Poor a cup of water in and you are asking for trouble but regular condensation won't be as big of an issue in diesels. And more what I mean by its the future of aviation fuel is that is a fuel that is EVERYWHERE. And if you dont have diesel right in front of you put your Jet A1 in and add a 50ml dose of additive. We would do the same thing if we had to fill up our rotaxs with 100LL with a lead scavenger. But we do it out of convenience instead of trying to go into town and finding mogas and having to cart 5 gallon jugs with us.

As for the algae growth in the fuel. Algae need sunlight to grow so yes if you take a cup of diesel and put it in a window you will get growth. I have never seen a clear fuel tank so I'm not worried about that one at all. Of course there is the chance but thats what fuel filters and regular maintainence is for. And compaired to the harzardoffuels with ethynol in it that many people run in their rotaxs I see that as a moot issue. When DeltaHawk comes out with thier 100HP two stroke diesel I will be all over that. Too bad they are prioritizing the V8 after the V4 is certified this year.

SkyPirate
09-26-2011, 08:47 AM
agreed on the maintenance ,..if your not changing the filters it will,..no matter what the fuel clog up ,..but I know in the north east as soon as the clock strikes October allot of the diesel fuel vendors start putting there own additives into the fuel as well,..Jet A still comes as Jet A no additives.
as for the motor ,..I wounder what the block is made of ,.. with the heat of 2 pistons traveling in one cylinder,..maybe a sleeved aluminuim alloy? or did they stick with the tried and true cast iron

( I'm in the sticks and couldnt watch the video so if it says something about the block construction ,.I don't know)

Mnflyer
09-26-2011, 03:13 PM
As for the algae growth in the fuel. Algae need sunlight to grow so yes if you take a cup of diesel and put it in a window you will get growth. I have never seen a clear fuel tank so I'm not worried about that one at all.
NOT True the bacteria grows in a completely dark tank whether it be above ground or underground. and it is particularly problematic at small airports that do have Jet fuel for sale as they don't sell enough of it and many small airport of the type that I fly into DO NOT have Jet fuel available.
Av8r3400 I did not say it was a problem in diesel trucks If you read my post, keep in mind just about all filling stations with diesel available probably turn over their complete supply ever couple of days not near long enough for bacteria to form and grow. BUT they all have water separators and drains and while I have only had a water problem a few times (it came from the filling station tanks) it was very aggravating sitting along side the road trying to get the water out of the separator and the truck started again.

And let me assure any and all of you I have seen the filter light come on many many times after refueling at a small airport with old Jet fuel and that means landing removing the fuel filter and installing a new one. I can also assure all of you that I have burnt up more Jet fuel in the past 30 years then most will ever see or buy, it is a good fuel but not trouble free as some might like to believe and it not any better in my book than good old 100LL when it comes to flying in a light plane, in a larger aircraft a turbine certainly has its advantages. Here's some reading so that real facts and not urban myths about BTU's etc.
If you do the math you'll find that Av Gas has more BTU's per lb than Jet Fuel does. Keep in mind tha Av gas is 6 lb per gal and Jet is 7 lbs.

http://www.doi.gov/pam/eneratt2.html
http://www.smartcockpit.com/data/pdfs/flightops/aerodynamics/Jet_Fuel_Characteristics.pdf

SkyPirate
09-26-2011, 03:30 PM
I know your right mnflyer ,..I have seen jets that went in for a engine transplant and where left with fuel in there tanks in a closed up hangar ,..then have to clean the tanks out becuase they didnt think it would take that long to replace the engine ,..nasty job.
these were privately owned jets that didnt have a corperate wallet to back the transplant.
Ever fly into Nashau NH Biore field and fuel up at GFW mnflyer? if you did back in the late 90's,chances are I fueled your plane,..unless you were flying anything bigger then a G4,..trying to think if that was the biggest plane that landed there or not ,..there were allot of small jets,.. citation 's etc..

Mnflyer
09-26-2011, 03:55 PM
Hi SkyPirate, no never flew out East, all of my time in turbines is in helicopters here in MN. Wis, and DA UP (Upper Mich for those not familiar with the term).

SkyPirate
09-26-2011, 04:55 PM
Ok ,..although i did fuel a few helo's too,..dont care for them much though ,.had my share of them in the military :) and when I was living next door to le juene and the 53's would rattle my windows all hours of the night ,..now in Missouri I don't see much for helicopters ..but I am right in the flight path of the B-2's what a sight :)

Mnflyer
09-26-2011, 05:37 PM
Hi AV8r3400, please explain:
Compression ignition engines are far superior to sparkies in every operational parameter.
Having been a mechanic for 50 years I fail to see the superiority for aircraft engines and for the most part personal vehicles now heavy trucks are a whole different store as are locomotive engine and in some instances heavy generators.

Mnflyer
09-26-2011, 07:22 PM
Here you go, like I said the engine layout / design is not new nor are diesel aircraft engines.
http://en.wikipedia.org/wiki/File:Jumo205_cutview_02.jpg

http://en.wikipedia.org/wiki/Opposed-piston_engine

http://en.wikipedia.org/wiki/Aircraft_diesel_engine
Here's another engine
http://www.deltahawkengines.com/

Esser
09-27-2011, 03:21 AM
I never said that I thought diesel was a miracle fuel. If it was all planes would be on it. But with enviromental adminstrations wanting to get rid of it completely I think it is the future. Mostly cause diesel is already made with supply chains in place and yes not all airports carry it but I'm sure you could find an airport that carries Jet A very close to your airport that does carry. This doesnt apply to older planes burning 100LL right now which is where the alternative fuels they are coming up with come in. Expect to pay BIG bucks to get those fuels when they first come out. You are also correct to say that diesel weighs in a 7 pounds vs six. It also has a BTU value of 130,000 vs 115,000 per US Gallon so weight vs BTUs there is only a 2.5% difference. Almost all diesels are turbo charged too which give more power poor with out the same decrease in fuel.

Diesel engines are not new in aviation by anymeans but the past cast heavy 4 strokes have put them at a disadvantage. Especially some of the auto conversions. The future for diesels are in the lower maintenance 2 strokes and aluminum blocks like the Deltahawk.

Every fuel has advantages and disadvantages but when they pull the rug out on 100LL I think diesels will gain popularity. Just my opinion

Mnflyer
09-27-2011, 07:02 AM
Hi Esser, I am just trying to keep the playing field level yes here in the US the EPA is pushing hard on 100LL that is because of the lead not because it's gasoline. I believe in one of your post you stated that water was not a problem in diesel but it is the same as gasoline water in any fuel is a problem. You just stated that gasoline has 115000 BTU's my research shows it has 125000 per pound gasoline has more btus than jet fuel it breaks down this way:
#2 diesel 138700 btu's per gal or 19814 per lb
jet fuel 130000 btu's per gal or 18571 per lb.
Av gas 125000 btu's per gal or 20833 per lb.
Another thing to consider a gas engine can easily be started down to -30*F not so easy with diesel fueled engines yes it can and is done but not as easily diesel fuel likes to gel near -40*F not so with gasoline.
Interna; combustion engines burning heavy fuels have been around as long as gasoline engines both types have there uses and advantages.

Esser
09-27-2011, 03:18 PM
I realize it is from the lead not the fact that it is gasoline. Anyhow good information. It will be interesting to see how the phase out of 100LL goes over.