i'm sure some of you will laugh at this question, but all the same, i'll ask it. i understand that many of you here have much more mc experience than me. and some of you swear by 2 stroke engines vs 4 stroke. now, i've taken a bit of mechanics but i'm not 100% an expert. it's my impression that 2 stroke engines produce more power than 4 stroke engines. i also believe that car engines are 4 stroke. would it be possible to build an engine for a car that is only 2 stroke? would you get more power out of it? or am i a moron for even suggesting this? :laugh:
Quote from: jserio on March 27, 2008, 10:09:09 AM
it's my impression that 2 stroke engines produce more power than 4 stroke engines.
In general, this is true. 2-stroke engines produce power on every cycle, while 4-stroke engines on every other cycle. 2-stroke engines are also a much simpler mechanical design (no valves etc.). Useful animations of the cycles can be found online:
- 2-stroke: http://science.howstuffworks.com/two-stroke2.htm (http://science.howstuffworks.com/two-stroke2.htm)
- 4-stroke: http://auto.howstuffworks.com/engine1.htm (http://auto.howstuffworks.com/engine1.htm)
Quotei also believe that car engines are 4 stroke. would it be possible to build an engine for a car that is only 2 stroke? would you get more power out of it? or am i a moron for even suggesting this? :laugh:
An engine is an engine; you could use it anywhere you want. Of course you could build a car with a 2-stroke engine! And it would be more powerful than its 4-stroke counterpart. The major downside (and the reason why 4-stroke engines have largely replaced the 2-stroke) is that a 2-stroke engine necessarily generates more emissions than a 4-stroke. As a consequence of lacking valves, it is much more difficult to control what is coming out the exhaust of a 2-stroke engine.
It is called a "Trabant".. look for it, it had a 2cycle engine. I think the P50 car from poland is also one with a 2 stroke. http://youtube.com/watch?v=iN0LQJLabqA
Suburu made a 2 stroke rally car way back in the day that put down some seriously impressive numbers.
i've also heard that 2 stroke engines are relatively simple as engines go in terms of repair and maintenane as well. aside from the emmissions issues. i mean, wouldn't it be wonderful to turn the new viper engine into a 2 stroke? :laugh: or any 8 cylinder for that matter. :icon_mrgreen:
am i dreaming or would that even be possible? if a 4 stroke 8 cylinder can produce 600+ hp how much would it produce were it only a 2 stroke? how would this be achieved anyhow? :dunno_white:
Turning an 8 cylinder 4 stroke into a 2 stroke would not be an easy undertaking.
Check this out for a better understanding of the 2 stroke engine. : http://science.howstuffworks.com/two-stroke.htm
also youd have to do engine overhauls on a more frequent basis with a 2 smoker. btw the 4 stroke engine runs on the whorehouse principle
what is that you ask?, it is,
1 suck
2 squeeze
3 bang
4 blow
:laugh: i don't really have any intentions of building such and engine i was just curious bout the topic. i think of shaZam! to post when i'm at work. it helps pass the time. workin 3pm-11pm sucks.
lol iwsh i had the opportunity to post at work :mad: :laugh: :laugh: :laugh:
oh, no. i don't post at work. i think of things to post when i'm at work to pass the time. then when i get home, i post em! :thumb: at least most nights i try to do that. hell, some nights my machine gives me fits and won't hold any tolerances at all so i'm stuck adjusting things all night long. :thumb:
lol been there man, been there many=o-times
How about an 18 cylinder, 2-stroke, opposed piston, liquid cooled, supercharged and intercooled Diesel engine.
http://en.wikipedia.org/wiki/Napier_Deltic
I was wondering when someone was gonna bring up that monster :thumb:
before you go all gaga over the hp numbers, remember how much time is spent idling in traffic or cruising at 55-70 mph. having 600 hp really doesn't benefit you in vehicles we drive typically. take for instance the family sedan. it needs around 120-180 hp to accelerate confidently enough onto interstates, and but over a large rpm range, thanks to typical gearing, of 1,2,3,4,5 or more gear ranges.
a 2 stroke with 600 hp in a camry (lets just pick on toyota for the moment) would be great for burning up on ramps and super fast acceleration. everyday driving doesn't NEED 600 hp though. you need smooth torque, which is available at low operating rpm's (say 2000-3000) and the ability to idle without problems.
then you get into reliability issues, and service life. 2 strokes just caught one in the eye.
maybe looking at the advantages of a turbo diesel is more beneficial ? very good fuel economy, amazing possibilities with a blower, and still able to idle in traffic without issue. yes, you could get 600 horses out of a diesel, but that's peak power, and i think you'd rather drive around/tow/play with 400 ftlb of torque instead. passing with torque feels neeeeeeeat. passing with hp means keeping the gear selection perfect for the power band. there is a big difference, and it's really neat to try.
check out some videos of what is possible with those amazing little subaru WRX's. then imagine getting 20-40% better fuel economy with a diesel powerplant instead of gas, and the SAME power numbers. it's cool stuff
:D
Take for instance the 2007 MB E320 Bluetec: 200hp and 400lbs/ft while producing about the same amount of noise as a hybrid and significantly less pollutants than most associate with a diesel.
Tel?
My dad worked for Napier/Eng-Elec in the late 60s when he came out of the Navy and he was heavily involved with the Locomotive varients of the Deltic....no shaZam! man. I can remember him taking me round the factory in Liverpool when I was a kid and bursting into tears with fright when they started one up on a test-bed :laugh:
I've never heard one in real life but I can imagine it's an awesome sound. The design really is ingenious albeit relatively simple.
QuoteA turbo-compound variant of the Deltic was planned[1]. This would have inserted the turbine stage from a Rolls-Royce Nene turbojet into the centre of the delta. The engine acted as the gas generator, driving the turbine with the exhaust gases, recycling some energy that would otherwise have been lost. Such an engine was hoped to produce 6,000 horse power.
Wow, that would have been a hell of an engine!!
Fisrt off before going gaga over horsepower numbers let's look at torque figures......pleaseeeeee
Horsepower is great it is the motive force that keeps the mass moving along at whatever your chosen speed is. Tourque is what drives massive acceleration.
Lets pick on the theoretical toyota again if we had a motor developing 600hp and 1ft/lb tourque id would not burn up acceleration ramps it would inch it's way forwards..... eventually on a 200 mile long straight said toyaota could reach 180mph and it would have the horsepower to maintain that speed. Now invert those numbers and lets run the 1hp 600ft/lb of tourque theoretical toyota up the ramp it can reach 180mph in less than a mile but as soon as you quit accelerating it just keeps slowing down because your 1hp is barely enough to maintain forward momentum at 1/2 mph.
Ok I was just picking on scott, big horse power big tourque and low rotational mass these things excite me :thumb:
Quote from: spcterry on March 28, 2008, 08:15:40 AM
I've never heard one in real life but I can imagine it's an awesome sound. The design really is ingenious albeit relatively simple.
Amazing sound? Oohhhhh yes! Riding behind a class 55 is a real treat.
Simple? If 18 cylinders, 36 pistons, three crankshafts, 56 timing gears, and three camshafts is simple, what's complicated? Napier, like Rolls Royce, isn't afraid of complicated machinery.
The P&W J58 is a complex engine, in relation everything is simple.
None of the tech involved in the Deltic engines is significantly more complicated than a standard engine, it's just designed differently.
Simple wasn't really the word I was looking for, regardless it's an ingenious design based upon principles already in existence.
Quote from: bettingpython on March 28, 2008, 08:59:14 AM
Fisrt off before going gaga over horsepower numbers let's look at torque figures......pleaseeeeee
Horsepower is great it is the motive force that keeps the mass moving along at whatever your chosen speed is. Tourque is what drives massive acceleration.
Lets pick on the theoretical toyota again if we had a motor developing 600hp and 1ft/lb tourque id would not burn up acceleration ramps it would inch it's way forwards..... eventually on a 200 mile long straight said toyaota could reach 180mph and it would have the horsepower to maintain that speed. Now invert those numbers and lets run the 1hp 600ft/lb of tourque theoretical toyota up the ramp it can reach 180mph in less than a mile but as soon as you quit accelerating it just keeps slowing down because your 1hp is barely enough to maintain forward momentum at 1/2 mph.
Ok I was just picking on scott, big horse power big tourque and low rotational mass these things excite me :thumb:
Nice. I've never considered it that way. Excellent explanation. Bump.
Ooooops I wasn't making fun of scott's post..... :oops:
Yeah I was having some fun with your post ohgood :thumb:
Glad you like the explanation, I know it's a bit simplistic but it's one of the esaiest ways to introduce the concepts of tourqe and horsepower to people.