RE: Turbocharged nitro engines

RE: Turbocharged nitro engines Gallery slideshow

View related threads: (in this forum | in all forums)

Logged in as Guest

Users viewing this topic: none

Search This Thread

Printable Version

All Forums >> RC Cars, Buggies, Trucks, Tanks and more >> RC Car General Discussions >> RE: Turbocharged nitro engines Page: << < prev 1 [2] 3 4 5 next > >>

Message

<< Older Topic Newer Topic >>

RE: Turbocharged nitro engines - 12/24/2012 9:20 PM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

quote:

ORIGINAL: 757jonp

The whole idea of turbocharging/supercharging an engine is to pack in more air into the cylinder. (simple as that, no more no less) More air means you can introduce more fuel equals more power. Doesn't matter if it's just air, or an air/fuel mixture, just get more of it in there than what you can do under normally aspirated conditions. The loop scavaged 2 stroke engines that we associate with our hobbies do not respond well to supercharging/turbocharging because there is no effective way to control the intake/exhaust timing event. Take a look at it... the only time the combustion chamber is sealed or blocked off is when the piston seals the exhaust port. Blow all the air into you want, but you've already lost it out the exhaust before the piston ''captured'' it. Remember also that the intake and the pressurized air you're trying to get in that cylinder was also cut off before the the exhaust was closed, further reducing it's effectiveness...ie, you shut it off before it even had a chance to get in there! The guy with the turbo heli might be making boost at the intake manifold, but is he getting it in the cylinder where it might do some good? Maybe a little, but I doubt it's amounting to much. More than likely just blowing more fuel/air out the tailpipe. Yes, there are 2 stroke engines that use turbocharging, I've worked with them for years, names like Cooper Bessemer, Fairbanks Morse, EMD, Detroit diesel. Most just use a turbo or supercharger to introduce a cleaner charge of air for the next power cycle. EMD and DD are uniflow 2 strokes. You have an exhaust valve in which allows one to control the timing more effectively and a blower to scavenge the cylinder.

Any four cycle engine is more conducive to turbo/supercharging, basically because you have a better method to control the timing events. Ys engines has done it for years using crankcase pressure and few valves to manage it. I realize it doesn't look all that ''trick'', but speaking from experience it defiantly works. Ask anyone that's used one.

Check it out....

http://www.qmfc.org/school/ys.htm

we have been turbo charging loop scavenging 2 strokes for decades .... there are many turbocharged 2 stroke snowmobiles.... Even simple piston port engines.............

you guys need to understand that the exhaust port is not wide open and unrestricted , it is only open into a tuned pipe which is under pressure itself....A pressure that is directly controlled by the volume of the exhaust being created.... more power means more pressure in the pipe....... These tuned pipes will give us the required resistance to allow the chamber to fill ......... All bosting is going to do is simulate a denser atmosphere.....The tuned pipes internal pressures will control the flow of exhaust both out of and back into the engine.....Putting in a larger head pressure will just result in a larger tail pressure , as when we pump in more air will increase the density and volume of the exhaust being pushed out, which in turn will create much higher pressures inside the tuned pipe for the boost to work against,( this same principle applies even to my modified engines)., which will on its own control the flow gasses out of and back into the engine..... As for every 3 CM the exhaust travels out , it back travels 1 CM...... it works on a sequences of pulses.... and the pressures controlling these pulses is determined by the volume of combustion being exhaled out of the combustion chamber..............

in the end the relative pressure difference between the inlet and the stinger plays little effect in the overall operation of the engine....And any compensation could be achieved very easily by reducing the stinger diameter...If needed of course.......

As long as the carb is fully encased the engine will operate like it is in a denser atmosphere.... it wont know the difference between the current static 14.7 PSI and 30 PSI...it wont matter one bit to the engine, it will just make more power because of the increased density of the atmosphere.... Same effect as going from very high altitude to very low altitude....

in the end you cant think of the tuned pipe being wide open, as it is not, it is at times under high pressure and wont allow mixture to just pour into it unrestricted.... it does not work that way...... If it did , these engines would not operate at all............ the tuned pipe actually has a huge amount of control over the flow rate of the mixture in both directions...out and in..... that control will only get stronger when we increase the intake charge into the engine.... we will just be giving the pipe more energy to work with to counteract the higher exhaust pressure created, the system will self balance....same way it does with my modifieds and when we change altitudes....

Also to note...the surrounding atmospheric pressure's affect on the internal pressure of the tuned pipe is extremely easy to correct for...... just changing the diameter of the stinger can compensate for the differential between the inlet pressure (carb neck) and stinger pressure.... All other internal functions of the pipe will remain 100% the same........

what is even crazier, is with a higher inlet pressure we can actually get more efficiency from the return pulse of the tuned pipe.....in other words the " Supercharging effect" of the tuned pipe will be even more pronounced under a higher inlet pressure.......

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to 757jonp)

Post #: 26

RE: Turbocharged nitro engines - 12/24/2012 10:42 PM

i8tweety

Certified

Posts: 4207
Score: 133
Joined: 10/27/2002
Last Login: 5/25/2013
From: Northridge, ON, CANADA
Status: offline

OS made a .26 4 stroke for surface use (car / truck) several years ago. I don't know if they are still available (or even if rebuild parts would be). Anyone looking to try forced induction on a glow 4 stroke, no modifications for attaching a clutch.

_____________________________

1 Bad Puddy Tat

Hide Signatures

(in reply to supertib)

Post #: 27

RE: Turbocharged nitro engines - 12/24/2012 10:46 PM

757sean

Posts: 2
Score: 100
Joined: 1/4/2009
Last Login: 1/12/2013
From: williamsburg, VA, USA
Status: offline

I'll go along with what Mr Smith is saying... in effect a reverse wave from the exhaust "slapping" the charge back up into the cylinder. (Yes..I understand how tuned pipes work) It'll make power... but usually with a very narrow power band. Not sure how you're going to combine a tuned pipe with a turbo.

Believe or not I've been around a few turbocharged 2 stroke bikes and snowmobiles, outboards. From what I've observed it's pretty much wide open or nothing, not to mention thirsty. Pretty inefficient, but it works for what it's intended for. Go fast, then shut it off.

Correct me if I'm wrong?

Any particular reason your not drawing through the turbo instead using the carb in a box trick? suck instead of blow?

Hide Signatures

(in reply to supertib)

Post #: 28

RE: Turbocharged nitro engines - 12/24/2012 11:24 PM

Anthoop

Posts: 1842
Score: 121
Joined: 2/3/2007
Last Login: 5/25/2013
From: Somerset, UNITED KINGDOM
Status: offline

quote:

ORIGINAL: t-max97

quote:

ORIGINAL: Anthoop

quote:

ORIGINAL: supertib
A carb is just like a airbrush...increase the airflow thru it and it will increase the volume of fuel is sprays.....a special injector is not needed here, the carb on its own works quite fine for handling ''boost ''....... If we double the volume of air passing thru the carb is will spray out double the volume of fuel it normally would............ this is fact of how a carb works........

Not really..no. The size of the jet will determine how much fuel/paint it can pass, the airflow provides the atomisation. More airflow requires more fuel/paint.

Nope Supertib is right, read this. http://www.nitrorc.com/articles/carb/default.asp

Not sure what you are trying to say...but a thing with a hole in it (fuel jet) can only pass a certain amount (no matter how hard you suck/blow it)...if you want to flow more you put a bigger hole.

_____________________________

When I die, I want to go in my sleep like my grandfather,not screaming
like the passengers in his car at the time.

Hide Signatures

(in reply to t-max97)

Post #: 29

RE: Turbocharged nitro engines - 12/25/2012 1:47 AM

t-max97

Posts: 1775
Score: 168
Joined: 11/7/2008
Last Login: 5/25/2013
From: White, GA, USA
Status: offline

quote:

ORIGINAL: Anthoop

quote:

ORIGINAL: t-max97

quote:

ORIGINAL: Anthoop

quote:

ORIGINAL: supertib
A carb is just like a airbrush...increase the airflow thru it and it will increase the volume of fuel is sprays.....a special injector is not needed here, the carb on its own works quite fine for handling ''boost ''....... If we double the volume of air passing thru the carb is will spray out double the volume of fuel it normally would............ this is fact of how a carb works........

Not really..no. The size of the jet will determine how much fuel/paint it can pass, the airflow provides the atomisation. More airflow requires more fuel/paint.

Nope Supertib is right, read this. http://www.nitrorc.com/articles/carb/default.asp

Not sure what you are trying to say...but a thing with a hole in it (fuel jet) can only pass a certain amount (no matter how hard you suck/blow it)...if you want to flow more you put a bigger hole.

True but think of it like drinking threw a straw, if you suck more "no jokes guys" more comes out, of course up to a point.

_____________________________

If you dont know what your doing, its best to do it quickly.

Hide Signatures

(in reply to Anthoop)

Post #: 30

RE: Turbocharged nitro engines - 12/25/2012 5:43 AM

straitnickel

Posts: 358
Score: 105
Joined: 9/1/2007
Last Login: 5/24/2013
From: pikesville , MD, USA
Status: offline

Blow some engines first then think about a waste gate.

_____________________________

I don''''t always crash, but when I do!

Hide Signatures

(in reply to BKoz559)

Post #: 31

RE: Turbocharged nitro engines - 12/25/2012 9:11 AM

byrne1157

Posts: 43
Score: 100
Joined: 3/2/2011
Last Login: 5/14/2013
From: Mount Morris, MI, USA
Status: offline

Turbocharging a carbureted engine is difficult at best, you'd need an injector system, or the idle characteristics would be unmanageable. you'd also need a waste-gate system to manage boost. It would be more fun to create a nitrous boost system....but, that would blow the heat out of the glow plug, you'd need to have a spark system for ignition. And yes, you do have to add more fuel to the increased volume of air blown into the engine, or create such a lean condition, the piston would end up with a hole in the top, or, the head would blow off.

Hide Signatures

(in reply to straitnickel)

Post #: 32

RE: Turbocharged nitro engines - 12/25/2012 1:40 PM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

quote:

ORIGINAL: Anthoop

quote:

ORIGINAL: t-max97

quote:

ORIGINAL: Anthoop

quote:

ORIGINAL: supertib
A carb is just like a airbrush...increase the airflow thru it and it will increase the volume of fuel is sprays.....a special injector is not needed here, the carb on its own works quite fine for handling ''boost ''....... If we double the volume of air passing thru the carb is will spray out double the volume of fuel it normally would............ this is fact of how a carb works........

Not really..no. The size of the jet will determine how much fuel/paint it can pass, the airflow provides the atomisation. More airflow requires more fuel/paint.

Nope Supertib is right, read this. http://www.nitrorc.com/articles/carb/default.asp

Not sure what you are trying to say...but a thing with a hole in it (fuel jet) can only pass a certain amount (no matter how hard you suck/blow it)...if you want to flow more you put a bigger hole.

there is no limit...increase pressure and the fuel volume will increase infinitely with the air volume........

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to Anthoop)

Post #: 33

RE: Turbocharged nitro engines - 12/25/2012 3:15 PM

Anthoop

Posts: 1842
Score: 121
Joined: 2/3/2007
Last Login: 5/25/2013
From: Somerset, UNITED KINGDOM
Status: offline

So...to use the airbrush analogy again....I can paint a full size truck trailer with an airbrush, or I can do artwork on a watch face, I just need the correct air pressure?

_____________________________

When I die, I want to go in my sleep like my grandfather,not screaming
like the passengers in his car at the time.

Hide Signatures

(in reply to supertib)

Post #: 34

RE: Turbocharged nitro engines - 12/25/2012 4:52 PM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

quote:

ORIGINAL: Anthoop

So...to use the airbrush analogy again....I can paint a full size truck trailer with an airbrush, or I can do artwork on a watch face, I just need the correct air pressure?

It is all relative.....If you put enough pressure behind the airbrush it can move a large volume of pain...yes............. Say maybe a airbrush with 2000 PSI behind it will likely push as much paint as a regular cup gun at 90 PSI...There is no real finite limit to the volume of fluid an orifice can pass... the greater the pressure differential between the two sides, the greater the volume of fluid will transfer.... Now of course to move a massive volume a tiny orifice will require massive amounts of pressure differential between the two sides...... Making it very inefficient......But for boosting these engines we are going to be nowhere near that scenario.... I mean realistically if we boost their performance by 30% we would be doing good, and that will be well within the limits of these carbs...Will be no different then from going from 10 000 feet altitude down toe sea level.....A couple little tweaks of the needles and the carb will tune right in ................

Anyways for those who are maybe not up to speed....I do not not plan to build a turbo system or supercharger system... All I plan to do is to prove that these little nitro`s can be boosted....How I intend to do that is by building a sealed air intake box that the carb will breath from, I Will have the air box connected to a air compressor and a pressure regulator........So I will be able to artificially simulate a high pressure atmosphere of any value I choose...from 0 PSi all the way up to 150 PSI ( my shops upper limit) .....Tho obviously I Will go nowhere near 150 PSI LOL...the regulator will maintain a constant pressure no matter the volume of air the engine ingests....... This test will show us whether or not the intake mixture will just blow right thru the engine due to the fact the intake and exhaust port are open at the same time..... As many here seem to believe boosting 2 strokes is impossible due to this fact..

As explained in my previous posts I believe these nitro engines can indeed be boosted and I believe my test will show strong evidence of this....

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to Anthoop)

Post #: 35

RE: Turbocharged nitro engines - 12/25/2012 7:00 PM

Anthoop

Posts: 1842
Score: 121
Joined: 2/3/2007
Last Login: 5/25/2013
From: Somerset, UNITED KINGDOM
Status: offline

quote:

ORIGINAL: supertib

quote:

ORIGINAL: Anthoop

So...to use the airbrush analogy again....I can paint a full size truck trailer with an airbrush, or I can do artwork on a watch face, I just need the correct air pressure?

It is all relative.....If you put enough pressure behind the airbrush it can move a large volume of pain...yes............. Say maybe a airbrush with 2000 PSI behind it will likely push as much paint as a regular cup gun at 90 PSI...There is no real finite limit to the volume of fluid an orifice can pass... the greater the pressure differential between the two sides, the greater the volume of fluid will transfer.... Now of course to move a massive volume a tiny orifice will require massive amounts of pressure differential between the two sides...... Making it very inefficient......But for boosting these engines we are going to be nowhere near that scenario.... I mean realistically if we boost their performance by 30% we would be doing good, and that will be well within the limits of these carbs...Will be no different then from going from 10 000 feet altitude down toe sea level.....A couple little tweaks of the needles and the carb will tune right in ................

Anyways for those who are maybe not up to speed....I do not not plan to build a turbo system or supercharger system... All I plan to do is to prove that these little nitro`s can be boosted....How I intend to do that is by building a sealed air intake box that the carb will breath from, I Will have the air box connected to a air compressor and a pressure regulator........So I will be able to artificially simulate a high pressure atmosphere of any value I choose...from 0 PSi all the way up to 150 PSI ( my shops upper limit) .....Tho obviously I Will go nowhere near 150 PSI LOL...the regulator will maintain a constant pressure no matter the volume of air the engine ingests....... This test will show us whether or not the intake mixture will just blow right thru the engine due to the fact the intake and exhaust port are open at the same time..... As many here seem to believe boosting 2 strokes is impossible due to this fact..

As explained in my previous posts I believe these nitro engines can indeed be boosted and I believe my test will show strong evidence of this....

I recomend you try an airbrush.
Looking forward to some test results though....show me how it will run lean when you add more air....

_____________________________

When I die, I want to go in my sleep like my grandfather,not screaming
like the passengers in his car at the time.

Hide Signatures

(in reply to supertib)

Post #: 36

RE: Turbocharged nitro engines - 12/25/2012 8:21 PM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

quote:

ORIGINAL: Anthoop

quote:

ORIGINAL: supertib

quote:

ORIGINAL: Anthoop

So...to use the airbrush analogy again....I can paint a full size truck trailer with an airbrush, or I can do artwork on a watch face, I just need the correct air pressure?

It is all relative.....If you put enough pressure behind the airbrush it can move a large volume of pain...yes............. Say maybe a airbrush with 2000 PSI behind it will likely push as much paint as a regular cup gun at 90 PSI...There is no real finite limit to the volume of fluid an orifice can pass... the greater the pressure differential between the two sides, the greater the volume of fluid will transfer.... Now of course to move a massive volume a tiny orifice will require massive amounts of pressure differential between the two sides...... Making it very inefficient......But for boosting these engines we are going to be nowhere near that scenario.... I mean realistically if we boost their performance by 30% we would be doing good, and that will be well within the limits of these carbs...Will be no different then from going from 10 000 feet altitude down toe sea level.....A couple little tweaks of the needles and the carb will tune right in ................

Anyways for those who are maybe not up to speed....I do not not plan to build a turbo system or supercharger system... All I plan to do is to prove that these little nitro`s can be boosted....How I intend to do that is by building a sealed air intake box that the carb will breath from, I Will have the air box connected to a air compressor and a pressure regulator........So I will be able to artificially simulate a high pressure atmosphere of any value I choose...from 0 PSi all the way up to 150 PSI ( my shops upper limit) .....Tho obviously I Will go nowhere near 150 PSI LOL...the regulator will maintain a constant pressure no matter the volume of air the engine ingests....... This test will show us whether or not the intake mixture will just blow right thru the engine due to the fact the intake and exhaust port are open at the same time..... As many here seem to believe boosting 2 strokes is impossible due to this fact..

As explained in my previous posts I believe these nitro engines can indeed be boosted and I believe my test will show strong evidence of this....

I recomend you try an airbrush.
Looking forward to some test results though....show me how it will run lean when you add more air....

I have had Airbrushes for 30 years now....and I have also been playing with nitro engines for 27 years........So make no mistake about it, I know very well the mechanics behind both a airbrush and a carburetor...

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to Anthoop)

Post #: 37

RE: Turbocharged nitro engines - 12/26/2012 2:18 AM

phmaximus

Posts: 4185
Score: 627
Joined: 6/8/2008
Last Login: 5/24/2013
From: Adelaideaustralia, AUSTRALIA
Status: offline

From what i understand is, yes the bost can escape out the exhaust, but of u pump in more in than what can escape it will have positive pressure. But yes it would be very fuel thirsty when coming onto boost

_____________________________

Losi Micro SCT,5IVE,8IGHTe
Tamiya BajaKing,TA01R,TL01B

Hide Signatures

(in reply to supertib)

Post #: 38

RE: Turbocharged nitro engines - 12/26/2012 2:57 AM

byrne1157

Posts: 43
Score: 100
Joined: 3/2/2011
Last Login: 5/14/2013
From: Mount Morris, MI, USA
Status: offline

Having been involved in internal combution theory, building, maintenance for the past 40 years, I have some knowledge about the subject. First, a carb is not an airbrush. Even though they operate on the same principle, they are not the same. Second, If you should be inclined to read and learn about engines that run on air that has had it's density increased to a value greater than ambient, you will find the fuel curve must allow for a greater amount of fuel than that required at ambient air pressure. This is due to the ideal air/fuel ratio of approximately 14.7:1 required for complete and most efficient combustion. Even if the air intake is artificially increased (nitrous oxide injection) additional fuel is required to maintain this ratio. This is because additional oxygen is added, which would cause a lean condition to such an extent that the engine would suffer catastrophic failure.

Hide Signatures

(in reply to phmaximus)

Post #: 39

RE: Turbocharged nitro engines - 12/26/2012 3:18 AM

phmaximus

Posts: 4185
Score: 627
Joined: 6/8/2008
Last Login: 5/24/2013
From: Adelaideaustralia, AUSTRALIA
Status: offline

What about the small dry nitrous kits, with them don't u tune to 12.5:1 then the nitrous leans it to 14.7.

Nitrous is a great way to get a turbo spooling... Hummmmm....

_____________________________

Losi Micro SCT,5IVE,8IGHTe
Tamiya BajaKing,TA01R,TL01B

Hide Signatures

(in reply to byrne1157)

Post #: 40

RE: Turbocharged nitro engines - 12/26/2012 3:33 AM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

quote:

ORIGINAL: byrne1157

Having been involved in internal combution theory, building, maintenance for the past 40 years, I have some knowledge about the subject. First, a carb is not an airbrush. Even though they operate on the same principle, they are not the same. Second, If you should be inclined to read and learn about engines that run on air that has had it's density increased to a value greater than ambient, you will find the fuel curve must allow for a greater amount of fuel than that required at ambient air pressure. This is due to the ideal air/fuel ratio of approximately 14.7:1 required for complete and most efficient combustion. Even if the air intake is artificially increased (nitrous oxide injection) additional fuel is required to maintain this ratio. This is because additional oxygen is added, which would cause a lean condition to such an extent that the engine would suffer catastrophic failure.

take the time to actually read what I am going to do.... I will have absolutely no issue tuning the carb for my test...... When you increase airflow past the venturi it will also increase the volume fo fuel being picked up.......... And if there is any lack of fuel I will just fatten the needles a little.... this is child's play LOL

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to byrne1157)

Post #: 41

RE: Turbocharged nitro engines - 12/26/2012 3:34 AM

phmaximus

Posts: 4185
Score: 627
Joined: 6/8/2008
Last Login: 5/24/2013
From: Adelaideaustralia, AUSTRALIA
Status: offline

Hey I had a idea? What about make a turbo rotary? The os 49-PI type 2 would be cool....

Or what about a electric supercharger? Brushless Ducted plane fan?

_____________________________

Losi Micro SCT,5IVE,8IGHTe
Tamiya BajaKing,TA01R,TL01B

Hide Signatures

(in reply to phmaximus)

Post #: 42

RE: Turbocharged nitro engines - 12/26/2012 3:52 AM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

I only look at this in terms of pressure differential..... My modifieds will at times run triple the the pressure differential as a stock engine will and we have no issues with the carb supplying fuel flow...And to date I have not come anywhere close to maxing out the supply capacity of these carbs...... Doing a 20% power increase by boost will be a piece of cake for these carbs

Also for my test on the dyno I will encase the entire carb.... just to elimate any differential issues with the carb body itself..... My test will create a artificially dense atmosphere for the engine to run in.... I will dyno test the engine in ambient then I will start increasing the plenum pressure and dyno testing ..... I will make any carb adjustments needed as I go along.....

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to supertib)

Post #: 43

RE: Turbocharged nitro engines - 12/26/2012 5:31 AM

TheKennyKiller

Posts: 1747
Score: 462
Joined: 8/18/2007
Last Login: 1/23/2013
From: QLD, , AUSTRALIA
Status: offline

quote:

ORIGINAL: byrne1157

Having been involved in internal combution theory, building, maintenance for the past 40 years, I have some knowledge about the subject. First, a carb is not an airbrush. Even though they operate on the same principle, they are not the same. Second, If you should be inclined to read and learn about engines that run on air that has had it's density increased to a value greater than ambient, you will find the fuel curve must allow for a greater amount of fuel than that required at ambient air pressure. This is due to the ideal air/fuel ratio of approximately 14.7:1 required for complete and most efficient combustion. Even if the air intake is artificially increased (nitrous oxide injection) additional fuel is required to maintain this ratio. This is because additional oxygen is added, which would cause a lean condition to such an extent that the engine would suffer catastrophic failure.

I fully agree, one is for mixing air and fuel while the other is for painting stuff. Completely different.

_____________________________

Do you even RC?

Hide Signatures

(in reply to byrne1157)

Post #: 44

RE: Turbocharged nitro engines - 12/26/2012 9:17 AM

phmaximus

Posts: 4185
Score: 627
Joined: 6/8/2008
Last Login: 5/24/2013
From: Adelaideaustralia, AUSTRALIA
Status: offline

quote:

ORIGINAL: supertib

I only look at this in terms of pressure differential..... My modifieds will at times run triple the the pressure differential as a stock engine will and we have no issues with the carb supplying fuel flow...And to date I have not come anywhere close to maxing out the supply capacity of these carbs...... Doing a 20% power increase by boost will be a piece of cake for these carbs

Also for my test on the dyno I will encase the entire carb.... just to elimate any differential issues with the carb body itself..... My test will create a artificially dense atmosphere for the engine to run in.... I will dyno test the engine in ambient then I will start increasing the plenum pressure and dyno testing ..... I will make any carb adjustments needed as I go along.....

I'm lost, I've seen 4bbl holleys incased before, ive got a great holey tuning book with heaps of info, but what's the advantage on the nitros carby? It's a sealed carby right?

I suspect that it might need a pressure equalizer hose with a one way valve going from the intake to the fuel tank.
And a one way valve fitted to the hose from the fuel tank to the muffler so it cant reverse the flow under boost.
With out a equalizer hose the pressure in the tank will be lower than the intake pressure causing negative fuel pressure under boost.
Venturi's don't like having a lower pressure at there pickup and a high pressure at the outlet.

But all those problems would be solved with a draw through carby

_____________________________

Losi Micro SCT,5IVE,8IGHTe
Tamiya BajaKing,TA01R,TL01B

Hide Signatures

(in reply to supertib)

Post #: 45

RE: Turbocharged nitro engines - 12/26/2012 10:15 AM

Anthoop

Posts: 1842
Score: 121
Joined: 2/3/2007
Last Login: 5/25/2013
From: Somerset, UNITED KINGDOM
Status: offline

quote:

ORIGINAL: phmaximus
Or what about a electric supercharger? Brushless Ducted plane fan?

http://www.youtube.com/watch?v=0EziHOHBqAw&list=UU5PPYZB8h2_txi-JqiHL_Pg&index=18

_____________________________

When I die, I want to go in my sleep like my grandfather,not screaming
like the passengers in his car at the time.

Hide Signatures

(in reply to phmaximus)

Post #: 46

RE: Turbocharged nitro engines - 12/26/2012 11:49 AM 1 votes

sparky 25

Posts: 1399
Score: 152
Joined: 5/24/2005
Last Login: 5/1/2013
From: Derry, IRELAND
Status: offline

quote:

ORIGINAL: phmaximus

quote:

ORIGINAL: supertib

I only look at this in terms of pressure differential..... My modifieds will at times run triple the the pressure differential as a stock engine will and we have no issues with the carb supplying fuel flow...And to date I have not come anywhere close to maxing out the supply capacity of these carbs...... Doing a 20% power increase by boost will be a piece of cake for these carbs

Also for my test on the dyno I will encase the entire carb.... just to elimate any differential issues with the carb body itself..... My test will create a artificially dense atmosphere for the engine to run in.... I will dyno test the engine in ambient then I will start increasing the plenum pressure and dyno testing ..... I will make any carb adjustments needed as I go along.....

I'm lost, I've seen 4bbl holleys incased before, ive got a great holey tuning book with heaps of info, but what's the advantage on the nitros carby? It's a sealed carby right?

I suspect that it might need a pressure equalizer hose with a one way valve going from the intake to the fuel tank.
And a one way valve fitted to the hose from the fuel tank to the muffler so it cant reverse the flow under boost.
With out a equalizer hose the pressure in the tank will be lower than the intake pressure causing negative fuel pressure under boost.
Venturi's don't like having a lower pressure at there pickup and a high pressure at the outlet.

But all those problems would be solved with a draw through carby

Your lost?
The man has already stated how he will regulate the boost,

_____________________________

Its me is that you?

Hide Signatures

(in reply to phmaximus)

Post #: 47

RE: Turbocharged nitro engines - 12/26/2012 2:21 PM

supertib

Posts: 6898
Score: 302
Joined: 3/30/2004
Last Login: 5/25/2013
From: , MB, CANADA
Status: offline

quote:

ORIGINAL: phmaximus

quote:

ORIGINAL: supertib

I only look at this in terms of pressure differential..... My modifieds will at times run triple the the pressure differential as a stock engine will and we have no issues with the carb supplying fuel flow...And to date I have not come anywhere close to maxing out the supply capacity of these carbs...... Doing a 20% power increase by boost will be a piece of cake for these carbs

Also for my test on the dyno I will encase the entire carb.... just to elimate any differential issues with the carb body itself..... My test will create a artificially dense atmosphere for the engine to run in.... I will dyno test the engine in ambient then I will start increasing the plenum pressure and dyno testing ..... I will make any carb adjustments needed as I go along.....

I'm lost, I've seen 4bbl holleys incased before, ive got a great holey tuning book with heaps of info, but what's the advantage on the nitros carby? It's a sealed carby right?

I suspect that it might need a pressure equalizer hose with a one way valve going from the intake to the fuel tank.
And a one way valve fitted to the hose from the fuel tank to the muffler so it cant reverse the flow under boost.
With out a equalizer hose the pressure in the tank will be lower than the intake pressure causing negative fuel pressure under boost.
Venturi's don't like having a lower pressure at there pickup and a high pressure at the outlet.

But all those problems would be solved with a draw through carby

Ummm..... there is no need to do that with the fuel tank, it would serve no purpose............. the fuel tanks pressure will be controlled by the tuned pipe........

secondly I am encasing the carb to make things easier....my possible concern if I didn't like is that the carb boot may not like a big pressure differential...and no these carbs are not sealed, the carb boots can leak.

_____________________________

Neal Smith..owner Clockwork Racing Engines

Hide Signatures

(in reply to phmaximus)

Post #: 48

RE: Turbocharged nitro engines - 12/26/2012 3:38 PM

Nitrovein

Posts: 102
Score: 100
Joined: 5/25/2010
Last Login: 5/24/2013
From: Skaraborg, SWEDEN
Status: offline

Well... Regarding flow/pressure, take a look at a modern Com Rail Diesel, they often run between 1000-1200 bar. And before you start to whine that it´s not a carb and so on, the proof is in the hole size vs pressure.
Then regarding the stoichiometric correct ratio; Gasoline 14,7:1, Methanol 6,4:1, Nitromethan 1,7:1. So, if the carb can meter fuels for users normally running between 16-30% of nitro it shouldn't have any problem getting things "in the ballpark". (Start to look at oil % and viscosity and the metering span is even greater)

Hide Signatures

(in reply to supertib)

Post #: 49

RE: Turbocharged nitro engines - 12/26/2012 6:13 PM

i8tweety

Certified

Posts: 4207
Score: 133
Joined: 10/27/2002
Last Login: 5/25/2013
From: Northridge, ON, CANADA
Status: offline

One thing to keep in mind relative to the potential lean condition as boost is increased. Intake air speed is not what is increased (may have marginal increase), air density is. Without an appreciable air speed increase, no increase in siphon effect for fuel delivery. Additionally, increased air density will reduce the pressure differential between the fuel needle and air venturi, providing even less fuel to the engine than without boost.

_____________________________

1 Bad Puddy Tat

Hide Signatures

(in reply to Nitrovein)

Post #: 50

Page: << < prev 1 [2] 3 4 5 next > >>

All Forums >> RC Cars, Buggies, Trucks, Tanks and more >> RC Car General Discussions >> RE: Turbocharged nitro engines
Page: << < prev 1 [2] 3 4 5 next > >>

Jump to:

Charities we support that also need your help
Yorkie Rescue | Humane Society | ASPCA | Crohn's-Colitis America

2.281RCU1