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Old 03-24-2004, 11:54 AM   #46
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Default turbo 2 stroke

it is poss. but inefficient! the exhaust is still open during critical cycles!


We call N.O.S. Jungle juice where I come from!
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Old 03-24-2004, 11:57 AM   #47
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Default Re: 2-stroke turbo-diesel engine

Quote:
Originally posted by orangbaligila
it's not directly related to our r/c engine,... but it has a 2-stroke cycle,... it's turbo-ed, and it' diesel (glow plug)

correct me if I'm wrong,... but these engineers can't be wrong in inventing this thing,...

so there you go a 2-stroke turo-glow-ignition engine to view,... in a (slightly) too big of a size...

http://www.bath.ac.uk/~ccsshb/12cyl/
Regarding other posts, I am all for people creating extreme projects for our cars (I personally try doing it myself). But I will express my thoughts on something I know doesnt work. Regarding this post on the diesel engine, off course it will work there.
But what you have to remember is our engines have no way to store the pressure until the combustion takes place to make the extra power. Thats why it doesnt work. With both our induction and exhaust ports open at the same time for approx 65deg the extra pressure from the turbo just blows the air and fuel straight out the exhaust port.

Again, I express I have nothing against extreme mods but I hate to see people waste money in a hobby that is already way too expensive.
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Old 03-24-2004, 11:57 AM   #48
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Default Re: turbo 2 stroke

Quote:
Originally posted by Slotmachine
it is poss. but inefficient! the exhaust is still open during critical cycles!


We call N.O.S. Jungle juice where I come from!
do it on air alone or dont do it at all!!!!!!
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Old 03-24-2004, 12:18 PM   #49
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Default Re: turbocharging 2-strokes

detroit diesels are two stroke engines.
you can rev the hell out of them, the only problems is they are a pain to tune and the time between teardowns is very short comparied to other diesels.
1.) The intake valves have been replaced by row of ports around the cylinder liner.
2.) A roots type blower is placed on the engine to blow air into the cylinder whenever the piston uncovers the port, each port has an angular inlet called the HESSELMAN HELICAL LOOP to swirl the air, creating turbulence with theresultant improvement in air fuel mixing.
3.) the unit injector injects fuel into the cylinder at the correct time.
4.) the exhaust valve or valves open to allow the blower to push the exhaust gas out of the cylinder.
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Old 03-24-2004, 12:36 PM   #50
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Default Re: Re: turbocharging 2-strokes

Quote:
Originally posted by drfritz
detroit diesels are two stroke engines.
you can rev the hell out of them, the only problems is they are a pain to tune and the time between teardowns is very short comparied to other diesels.
1.) The intake valves have been replaced by row of ports around the cylinder liner.
2.) A roots type blower is placed on the engine to blow air into the cylinder whenever the piston uncovers the port, each port has an angular inlet called the HESSELMAN HELICAL LOOP to swirl the air, creating turbulence with theresultant improvement in air fuel mixing.
3.) the unit injector injects fuel into the cylinder at the correct time.
4.) the exhaust valve or valves open to allow the blower to push the exhaust gas out of the cylinder.
Exactly, something our engines cant do hence the reason it doesnt work on them.
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Old 03-24-2004, 12:41 PM   #51
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Default Re: Re: Re: turbocharging 2-strokes

mmmmmmmm

Last edited by drfritz; 03-24-2004 at 01:24 PM.
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Old 03-24-2004, 01:19 PM   #52
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I dont understand why people thing it wont work?? On yeah that bike isnt a t-charger is a s-charger...turbos work off exhaust where as supercharger works off belt and crank. Turbos are more efficent. You r/c cars you could ealily make a "turbo". You dont need a turbocharger but make the exhuast go straight to the carb...through an intercooler first of course. That would give some boost and cooler air. Do we not all agree you DO want cooler air? Anybody that doesnt want or need cooler air sell any fuel powered items you have a buy a bike and electric things you have no sence at all. Many of you that have somewhat logical thinkings you have to remember that many young kids post on here that have nothing in the minds but what they have heard from other kids who dont know anything from the get go. The boost pushes the piston down and releases out the exhaust...thats what its supposed to do!! You think its supposed to keep building up more and more? The picture of the car with the tubes going in front to an intercooler is a great design and i would use it myself.....i would put some very small (if made) elec. fans on the intercooler. The only problem with these type of engines the oil is mixed in with the fuel which over time would clog the intercooler and such...just gotta stay on top of it and keep it clean. Supercharger, Turbocharger, CO2 and Nitrous Oxide will all work on any ic engine if anyone disagrees explain why not with facts not opinions to back it up
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Old 03-24-2004, 04:42 PM   #53
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Quote:
Originally posted by Brandon R
I dont understand why people thing it wont work?? On yeah that bike isnt a t-charger is a s-charger...turbos work off exhaust where as supercharger works off belt and crank. Turbos are more efficent. You r/c cars you could ealily make a "turbo". You dont need a turbocharger but make the exhuast go straight to the carb...through an intercooler first of course. That would give some boost and cooler air. Do we not all agree you DO want cooler air? Anybody that doesnt want or need cooler air sell any fuel powered items you have a buy a bike and electric things you have no sence at all. Many of you that have somewhat logical thinkings you have to remember that many young kids post on here that have nothing in the minds but what they have heard from other kids who dont know anything from the get go. The boost pushes the piston down and releases out the exhaust...thats what its supposed to do!! You think its supposed to keep building up more and more? The picture of the car with the tubes going in front to an intercooler is a great design and i would use it myself.....i would put some very small (if made) elec. fans on the intercooler. The only problem with these type of engines the oil is mixed in with the fuel which over time would clog the intercooler and such...just gotta stay on top of it and keep it clean. Supercharger, Turbocharger, CO2 and Nitrous Oxide will all work on any ic engine if anyone disagrees explain why not with facts not opinions to back it up
Your absolutely correct. Running pressure direct from the pipe is what you have to do. Thats the problem. The pressure feed from the pipe is required to the tank to keep the fuel feeding to the carb. Without it after so long the fuel feed would become irratic and the engine wouldnt run right anyway. So that rules out that idea on our little engines. Why do you think we spend so much time fussing over the length of the pressure feed pipe from the exhaust to the tank? Its really not for fun.
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Old 03-24-2004, 07:56 PM   #54
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This is my take on why force induction WILL not work in the WAY you think it will.
1.) timing, with out changing the timing, all that air is not doing you any good,
2.) the increase in presure is going to increase the heat and cause undo stress on the rod
3.) as we are talking about air, what is all that air doing to your fuel air mixtrue, leaning out the mixture, aka more heat, yes you can rich it up, but the faster the engine spins the more air the turbo,super charger will force in.
4.) if somebody did find a solution to all this problems and I'm sure theres a few that I did nit think of, how much wieght did you just place on the car?
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Old 03-24-2004, 08:10 PM   #55
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Supercharging or turbocharging will in theory work even in a high intake/exhaust overlap situation. However the power increase does not occur until very high in the power band, and you damage badly the torque curve on the bottom end. Also low RPM fuel economy is very very poor.

However in our model engines there are some additional complications.

1. Carburation. Our carbs are simple and very crude. They will not offer enough range to effectively get the engine to idle and low end well along with a forced induction top end.

2. Crankcase pressure. Our motors work by flowing the mixture through the crankcase not via valves. Thus they rely on the pressure in the crankcase to shift the mixture from the case to the combustion chamber (with some help from the crank big end shape). Messing with these pressures by adding a pressurised mixture into the crankcase will actually negatively affect performance as the piston while travelling downwards will now need to pressurise already pressured air also adding additional aerodynamic drag to the rod. Ever wondered why the rod is knife edged?
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Old 03-24-2004, 08:32 PM   #56
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Quote:
Originally posted by AMGRacer
Supercharging or turbocharging will in theory work even in a high intake/exhaust overlap situation. However the power increase does not occur until very high in the power band, and you damage badly the torque curve on the bottom end. Also low RPM fuel economy is very very poor.

However in our model engines there are some additional complications.

1. Carburation. Our carbs are simple and very crude. They will not offer enough range to effectively get the engine to idle and low end well along with a forced induction top end.

2. Crankcase pressure. Our motors work by flowing the mixture through the crankcase not via valves. Thus they rely on the pressure in the crankcase to shift the mixture from the case to the combustion chamber (with some help from the crank big end shape). Messing with these pressures by adding a pressurised mixture into the crankcase will actually negatively affect performance as the piston while travelling downwards will now need to pressurise already pressured air also adding additional aerodynamic drag to the rod. Ever wondered why the rod is knife edged?
hey I forgot about that, just to add to what you were saying about increase crank case pressure, were does that presuure go, any place that it find it can , thus out the front bearing ans any seal that is lacking.
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Old 03-24-2004, 08:39 PM   #57
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Quote:
Originally posted by drfritz
hey I forgot about that, just to add to what you were saying about increase crank case pressure, were does that presuure go, any place that it find it can , thus out the front bearing ans any seal that is lacking.
Yes if you increased the crank case pressure it will put extra strain on seals. Tolerances on backplate seals, front bearings and even the gap between the sleeve and block will be tested by any pressure increases. Our little nitro motors are pretty leaky already.
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Old 03-25-2004, 06:30 AM   #58
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Default Kawasaki

sorry about the kawasaki post,.. I meant "an FI-ed 2-stroke,... it was early morning and no coffee left,... my apologies for that...

if I (still) may say something in this thread,... all I meant about FI and other extreme mods were: they're do-able and will work,... efficiency is another story.

as for the rotary, I'm open if anyone wants to discuss it deeper,.. and its application on scale cars. But still, IMHO, rotaries aren't the most efficient engines,.. it's more a "cheat engine"... more displacement in smaller compartment.

The "fair" full scale race sanctioning bodies will actually rate engine capacity according to its ability to suck air/fuel mix in one revolution... example: FIM rules on Moto GP,... if a team runs 2-stroke, they can have up to 499cc of (conventional) displacement,.. using 4-stroke (I think currently) will allow the team to have 899cc of (conventional) displacement,... if in the future there are any team that decided to have rotary as their weapon of choice (not ruled yet,.. so it's considered outlaw),.. I'd say the team (IMHO) should be allowed to have only up to 175cc of (conventional) displacement.,... as rotaries have effectively 3 combustion cycle per revolution,.. against a 2-stroke' 1 combustion cycle per revolution... if not ruled this way,... for sure,..,. rotary will have unfair advantages on top of their current advantages (lighter, smaller, less moving parts,..etc,...)

my 2 cents
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Old 03-25-2004, 06:48 AM   #59
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Default Re: Re: 2-stroke turbo-diesel engine

Quote:
Originally posted by modellor
Regarding other posts, I am all for people creating extreme projects for our cars (I personally try doing it myself). But I will express my thoughts on something I know doesnt work. Regarding this post on the diesel engine, off course it will work there.
But what you have to remember is our engines have no way to store the pressure until the combustion takes place to make the extra power. Thats why it doesnt work. With both our induction and exhaust ports open at the same time for approx 65deg the extra pressure from the turbo just blows the air and fuel straight out the exhaust port.

Again, I express I have nothing against extreme mods but I hate to see people waste money in a hobby that is already way too expensive.
For some people (especially who did these kind of things already).. money obviously weren't the thing they talk about while making these kind of things,... (normally sponsored to do a research)...

my opinion on these mods (if you read my earlier posts thoroughly...) is they work,... but not as efficient as it was expected,... as for the valve overlap,... I'm pretty sure these guys won't leave them stock. so does the ignition timing (in this case plug height,.. or depth,... wire thickness,... material and many things) were changed... I didn't just add turbo to my stock Galant engine for instance,... that would be plainn stupid....

and one more thing,... if it would make the thing easier,... there are some 4-stroke glow-engines that will fit to 1/10 or superten car,.. OS' FS26 for instance,... I'd give it a try when someone has this engine and a turbo-kit for sale....


have a fine day
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Old 03-25-2004, 07:43 AM   #60
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I found this very cool mod... (not engine related )

http://www.snviper.ch.vu/

Hit the links under "SN Prototype Car" for info and "SNPC" thumbnails for a detailed look. Note that this car was once a HPI Super Nitro!

Respect!
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