Out of curiosity (Allison WWII engine like the V1710)

Discussion in 'Gas Engines' started by Schoonner, Dec 12, 2011.

  1. Schoonner
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    Schoonner Senior Member

    Has anyone ever built a boat with an Allison WWII engine like the V1710?

    I have heard that hydroplane engineers in the 60's and 70's put TONS of pressure on the engines by gearing the suprechargers differently and put water in the intakes that flashed to steam and cooled the intakes.

    I bet if you stayed within structural limits, and just rolled the heads and headers you could get 4000hp PLUS out of a V1710.. for a little while... The generals never fully tested the capabilities of those engines during the war, and by then they had... JETS!... Muhuwawawa!

    I've even seen pictures of a valve that works like a ball valve sitting in the head right on top of the combustion chamber. I bet that would relieve some of the pumping forces because you don't have to push the gasses past the valves anymore. Then if you used a blowdown turbine around the crankshaft you could probably get things really cooking.

    Maybe if everything were timed in the engine correctly by rolling the intake, the exhaust so you could REALLY tune them and the blowdown turbine and turbosuperchargers were combined into one unit you could get more efficiency. Especially if you built the engines with todays materials and disconnected half the valves so they would trap exhaust gases and you could cruise on 6 cylinders. Maybe it would be better to have two v6 engines with a torque converter between them and shut one down when you don't need it though. Probably depends on how big your boat is.

    Too bad we can't use lead in the fuel anymore... What if you put lead in the top of the chamber... nevermind, it would probably still go out the tailpipe... Not really sure what lead did other than allow for the price for gas to go up by now having to not put it in the gas, and at the same time efficiency went down so the demand increased over time.
     
    Last edited: Dec 12, 2011
  2. gonzo
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    gonzo Senior Member

    Efficiency of what goes down with no lead? The main thing it did was lubricate the valve faces and seats. With hardened seats and stainless or alloy valves that is not an issue. How does a ball valve relieve pumping forces? There has to be a vacuum to suck the fuel/air mixture into the cylinder.
     
  3. Schoonner
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    Schoonner Senior Member

    I don't know for sure. I am just going by what people have told me, or I have read about wwII engines and tried to simulate them in a computer game.

    There doesn't have to be a vacuum if you are forcing induction does there? I really don't know that much. so maybe I'm wrong. Check out turbocompound engines. They use exhaust gases to push a blowdown turbine that is moved by the velocity of the gases and not the pressure. The problem is that with a blowdown turbine the forces on the valves changes and poppit vlaves don't work. That turbine is geared to the crankshaft to help turn the crankshaft. If two turbines are stacked around the crankshaft and each converts a different type of energy will they work together to help eachother with not only the pumping of gasses, but also to turn the crankshaft won't it be more efficient by some margin? Also the rolling is to help it pump more easily. There are lots of different types of turbines right? Do some work with forces different enough so that they don't over lap as much and will both get more force applied independently? Say, if the velocity is turned into work first, then the left over pressure is used further downstream and also turned into work you might be able to get more work out of the same movement of gases.

    Sorry, I was editing that last post, and I thought I hadn't posted it yet.
     
  4. Schoonner
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    Schoonner Senior Member

    Sorry, I didn't really answer your question. I thought that because of the openness of a ball valve that the volume of gases could move through the valve more easily.
     
  5. gonzo
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    gonzo Senior Member

    I'm sorry but I can't follow your argument.
     
  6. Schoonner
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    Schoonner Senior Member

    That's okay, It is really difficult to say what I want to with it.
     
  7. Schoonner
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    Schoonner Senior Member

    How about this, I want to take a v12 with lots of displacement and roll and port the intake and headers for maximum flow. (ease the angle the gases have to flow around to get in and out of the engine.) Then I want to use ball valves. I forget what they use, ceramic or brass or something riding on gaskets made out of carbon that are self lubricating. I want these because the blowdown turbine destroys poppit valves.

    Then I want to stack two turbines so they are both geared to the crankshaft. Then the crankshaft turns the propellers, but also turns a supercharger. The two turbines use different forces to generate torque so they might work almost independently, but are both geared to the crankshaft and are connected to a blower through the crankshaft. I think it would reduce mechanical losses or whatever it is called when the mechanical parts themselves use up power. I think it would increase torque at the wheels and increase the fuel economy by using more of the gases to turn the crankshaft as well as power the forced induction devices.

    EDIT:: There are two turbos and one supergharger all connected to the crankshaft. The first turbo is powered with the velocity of the exhaust. The second turbo is powered with the pressure of the exhaust. The supercharger is powered off the crankshaft.

    Maybe it's a turbosupercompound engine? Or maybe it's just superturbocompound. LOL! Maybe it's turbo super confounded.....

    EDIT EDIT:: Maybe something like a rotary capable of more RPMS would benefit more than a v 12? Though with rotating valves instead of back and forth valves the RPMS could probably be safely increased because there is no chance for float.
     
  8. gonzo
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    gonzo Senior Member

    You need to study physics more. It is not possible for one turbo to work with the velocity of the exhaust and one with the pressure, or rather you are not understanding the basics. Turbo, short for turbine, is made of an impeller (foil) in a chamber. It transforms the flow of gases into force to turn a second turbine that moves air into the engine. They work well at higher RPMs. Superchargers work better a low RPMs, that is why many engines use both to increase power over a larger RPM range. I don't know who told you that turbos destroy valves. There have been millions in operation for decades without that happening.
    Rotary engines of the Wankel type use both superchargers and turbochargers. They've been around for 70 years or so.
     
  9. Schoonner
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    Schoonner Senior Member

    I am talking about a different kind of turbine mixed with a regular turbine. Check this out: http://en.wikipedia.org/wiki/Turbo-compound_engine

    QUOTE:: When a blowdown turbine is attached to an engine it will not reduce power due to exhaust gas flow restriction, since a blowdown turbine is a velocity turbine, not a pressure turbine as is a turbo supercharger. The exhaust restriction imparted by the three blowdown turbines used on the Wright R3350 is equal to a well-designed jet stack system used on a conventional radial engine. However, the blowdown turbines recover about 550 hp (410 kW) at METO (maximum continuous except for take-off) power.

    I guess that the 'recovered' horsepower is almost half the original horsepower resulting in about 140-something % total? I don't remember the exact output rating of the R3350.

    QUOTE:: In the case of the R-3350, maintenance crews sometimes nicknamed the turbine the "Parts Recovery Turbine" due to its negative effect on engine reliability.


    The negative effect on engine reliability is due to the poppit vlaves breaking because there is zero back pressure in the exhaust. You have to the right amount of back pressure in order for a pressure differential valve to seat and work properly, but maybe in the 1940's they didn't know that.


    Then, I would attach a regular turbocharger, and a supercharger to get the same effects you mentioned. Essentially, I would have a turbosupercharger, a turbocharger, and a supercharger all on the same engine probably resulting in much higher output and fuel economy. I wish I had a machine shop that could 'do anything, be everything'.
     
  10. Schoonner
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    Schoonner Senior Member

    OHH HEy look! This one already has a blowdown turbine!!

    Engine: STD Detroit Diesel DD13 (350-450 hp 1250-1650 lb-ft)

    EDIT:: Oh, wait no, this one : http://detroitdiesel.com/engines/dd15/economy.aspx

    Must watch the video on that page. and look at the graphs. Turbocompounding works better at low RPM just like a blower does. Yeah, I'm adding more fuel, but I'm doing more with it. I think that if I put the pressure actuated turbine first, and the the velocity actuated turbine last I might be able to get a LOT of velocity going down the pipes because if the vanes generate their own lift and pull themselves around the circle with a laminar flow airfoil that means that more vanes can be used more efficiently down the driveline and it will be easy because you can put pressure here, and create velocity, and then pressure again as it cools to keep the velocity flowing. With vanes sticking out of the shaft like like a turboprop engine for the full length of the driveshaft where it is dumped 90 degrees through a turbine that uses a friction ceofficient to turn.

    Turboprop engine:

    http://en.wikipedia.org/wiki/File:Turboprop_operation-en.svg

    EDIT" http://www.youtube.com/watch?v=yk-_IGd4xYE This will make the end of the turbines and the 90 degree bend to the final ehaust. Note that this could be used with more than one shaft. Oh, and I should go see if this powerboat has been shopped up yet. I want the motor and drive stuff off it since it might be worth something. (It starts and the wheels err, props?.. turn.)
     
  11. gonzo
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    gonzo Senior Member

    You can't have 140% power. That would violate the Laws of Thermodynamics.
    Valves do not fail because of lack of back pressure. They close with a spring, the pressure on either side in negligible.
     
  12. Schoonner
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    Schoonner Senior Member

    http://www.youtube.com/watch?v=JGqyzWQ8xwY&feature=related

    Oopse!! This propulsion system might get hotter. What if the turbines around the crankshaft were mounted inside a water hammer cylinder and the water hammer steam was vented through the tesla turbines and that generated electricity and unlimited hot water?
     
  13. Schoonner
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    Schoonner Senior Member

    Oh, Well, the mechanics in the 1940's wrote down exhaust valve failures every time, and my friend told me that's why a car engine has to have back pressure, but maybe he doesn't know what he is talking about.
     
  14. Schoonner
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    Schoonner Senior Member

    Nevermind, I'll just have to make myself send them an actual letter. That means going outside and doing stuff... BLEH... It's cold and foggy outside. EDIT:: That, and I stink at writing letters.

    They already made kinda what I'm talking about, but only about a third of what I'm talking about combining into one thing, the driveline, a water heating pump that can make electricity, several types of turbines, a wind tunnel, an aircompressor, a turbocharger, a super charger, and a turbosupercharger all into one device that tries to use ALL the exhaust gas inertia, momentem, energy, and heat that comes out of the engine. Thus providing HIGH amounts of torque at low rpm and therefore saving fuel as well as generating hot water or steam on demand.


    The stats for the Detroit Diesel: http://viewer.zmags.com/publication/8d45a42a#/8d45a42a/2
     

  15. Petros
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    Petros Senior Member

    You have to do a detailed study of the thermodynamics of engines before you can possibly understand what you are talking about. I have and had once worked for AirResearch in the turbo division as an applications engineer (that is sizing turbos for various engine configurations). And have worked for others in automotive related engineering positions.

    Adding a turbo or super charger does not increase its efficiency, it only makes a smaller engine act like a larger one when at full throttle. On a high altitude engine, as in aircraft, it also compensates for the thinning air as it goes up. Since most engines, including ship or boat engines, do not spend the majority of their time at full throttle (nor very far above sea level), the turbo does nothing but add weight, cost, complexity and maintenance headaches. Also, in aircraft weight is critical, so making a smaller engine act like a larger one has advantages, but it also costs in fuel consumption, shortening its range or combat radius. In a marine application you also need to consider total operational conditions, if you make a lot of power you will consume your fuel a lot faster, meaning you will not have much range. Also, your total fuel and engine bulk and weight combination will be much larger than with a less thirsty engine. If you are designing for a short closed course race, there is nothing that puts out more power per pound of engine than a pure turbo shaft engine.

    IT is very unlikely an engine designed over half a century ago is going to be better in any way than a modern engine that is designed by competent engineers around your application. The WWII engines used in the racing boats were only done because they were the largest engines you could get cheap at the time. Every aspect of engine design has improved tremendously, metallurgy, fuel injection, induction and exhaust system design, electrnic controls, etc. etc.

    You will not suddenly "discover" some hidden secret about making an engine more powerful or more efficient by resurrecting an obsolete engine design. If you should mange to fine one of those engines in a junk yard or at the bottom of a lake, you would be better off restoring it and selling on ebay, and than use that money to buy a modern engine for your boat. These engines are very valuable to wealthy collectors.

    With all the pressure on all engine manufacturers to become more efficient and put out less pollution, the industry is long past the point where a shade tree mechanic/inventor can discover something that the industry does not already know. Sorry that is just the way it is right now. You can find a big engine and throw a super/turbo charger on it, and perhaps even get a lot of power out of it, but it is unlikely it will out perform engines that are already available.
     
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