I don't remember this as being one of the arguments against. I'm searching for this now but not having much luck. To be exact, cooler air is denser? BTW, you can test this with a home-made tennis ball cannon made from soup cans. Throw the tennis ball cannon in the freezer for 30 minutes before using and you'll find you can propel tennis balls much further if it's filled with cool air than you can at normal, summer temps. I've heard of turbo'd 2T snowmobiles before. Never seen one, though The grandkids would love it if I can get it by a few of the females in the family.
You certainly can - if it's a 2 stroke diesel. In fact some sort of forced induction is a requirement. Many older 2 stroke Detroit Diesels were actually supercharged and turbocharged - the supercharger would get it started, and once the engine was running the turbo s would take over. How Stuff Works - Diesel 2 Stroke. Yes cc is correct. EMD and GE are the two major manufacturers of disel-electric locomotives. These have nonoscillating piston rods and crossheads, and the spaces above and below each piston are sealed.
The crankcase is not part of the fuel cycle and has ordinary oil in it. These things are bigger than houses. They are both 2 and 4 stroke. Supercharged and turbo charged. Now Diesel electric would be different.
You hit the nail on the head. The two major issues are the reed valves and loss of pressure thru the exhaust will the piston is at BDC. Diesles have managed to do it, but the use a poppet valve, which to me is not a true two cycle. I do have a plan that can resolve these complications but I need some help in order to create a working prototype to be tested.
My plan involves the same physics of a normal two cycle, but with a way increase compression without MOST of the pressure loss from the exhaust at BDC.
If you know of anyone that might like to help, I would be most generous. Do not know how you can not call them 2 cycles. One stroke. Piston starts up exhaust port closes intake valve closes compression begins. Oct 3, 46 0 6. Hi, are some days I try to understand well how work a turbo on a 2 stroke engine. Some people in this forum have try to explain me that and I thank all them. But I need more explanation about it. Because I think it is a very interesting argument and need to be study in deep.
So for what I've heard turbo provide a "balance" between intake and exhaust pressure and the fuel mixture isn't blow trough the exhaust port by the turbo boost because turbo do the necessary backpressure to contain that.
Exaust pressure need to be some psi over the intake pressure. It's all correct?? Oct 8, I won't go in tremendous depth on this, but I will discuss key ideas. Engines generate power based on the amount of mass flow passing through the motor. Mass flow only occurs from a point of high pressure to a point of lower pressure. If the pressure is equal at both points flow does not occur and power cannot be generated.
A turbo works based on the prior principle. Keeping it simple, boost increases IMAP and power is gained so long as the increase in EMAP, also called drive pressure, does not increase in proportion to boost.
When the change in boost equals the change in drive pressure, no more power is made, but you see more boost on the gauge. Therefore, a turbo will increase the volumetric efficiency of an engine and allow it to make more power so long as the change in boost is greater than the change in drive pressure. Finally, sparing many details, 2 strokes operate using pressure differentials between the intake and cylinder on the intake stroke and the cylinder and exhaust pipe on the exhaust stroke to generate mass flow.
Back pressure kills mass flow on a two stroke because it reduces the pressure differential. Compared to a 4 stroke, 2 strokes flow much more air per cc of displacement. That is why two strokes use such large turbos But, unlike 4strokes, which capture all of the air mass passing through the cylinder, a 2 stroke takes a sample of the air passing through it.
That means some portion of air and fuel mass is wasted into the pipe when it mixes with exhaust gases. Etec motors reduce fuel loss via direct injection after exhaust port closure. There is more to this, but that is all I will say at this point. Last edited: Oct 13, Thanks for your answer! Do you think reeds or rotary valve are mandatory to turbocharge a 2 stroke or is also possible do it on a piston port engine?
Anyway I'm not completely agree with you because if the exhaust pressure is lower than the intake pressure ALL the fuel mixture is blow out! So no power gain. Nov 26, 3, 1, Stayton Oregon. If you take a clear syringe and point it down into some fluid and pull up cc's of fluid according to the mark on the body of the syringe, then lift it up and turn the tip up, you will not have cc's of fluid.
You would typically have a percentage of that plus some air. This "percentage" is the volumetric efficiency of the vacuum device. Your pistons are also vacuum devices with a volumetric efficiency value. There are differences between 2 and 4 stroke engines but for simplicity I'll lump them together. Forced induction systems improve this volumetric efficiency of cylinder filling by pushing the mixture in.
Thus with more boost you have the more power the engine can make. Two2 said:. Click to expand That implies they start from a base pressure. I leave that out to simplify. Search forums. Log in. For a better experience, please enable JavaScript in your browser before proceeding. Thread starter blane.
It is considered not possible to turbo-supercharge a two stroke because of the conflict with the tuned exhaust. It is considered possible to mechanically supercharge a two stroke. Last edited: Jul 25, Snowmobile people turbocharge port valved 2 strokes all the time. It's totally possible. You can even tuned the tuned pipe to work under the higher pressure environment. Exahsut valve equipped 2 strokes are turbocharged "as a matter of course".
Most trains have engines like that. Bill-Higdon Well-Known Member. Joined Sep 8, Messages 6, Location Australian. Plenty of Yamaha Banshee Quads are now turbocharged, and man, are they fast.
There's a few on Youtube drag racing, and a few adverts for the kits. It could involve using that program called Google though, be careful. I can understand how a conventional two stroke would work supercharged for a very narrow rpm band considering the exhaust backpressure at least theoretically could be tuned to be strong enough to stuff in a bit of the fuel air mix and retain some of the compression of the supercharger.
In my mind it seems it would be a very narrow rpm band indeed and the amount of benefit from the compressor that could be retained is questionable. Otherwise to make supercharging work over a wide powerband it seems to me that you are at least going to have to have an exhaust valve.
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