t-max97

My Feedback: (9)

I didnt even think about that, your probably right. But guys lets just stop arguing lol untill someone tests it and can back up what they're saying.

supertib

air speed should increase due to the increase in pressure differential between the crankcase and atmosphere..............You must rember my test will be tuning against a fixed atmospheric pressure.... there will be no rise in boost as the RPM increases like a traditional boosted system.... all I am going to do is slowly increase the pressure of the atmosphere the engine breathes as I dyno test.... I will test at 14. 7 PSI, then test at 15.7..then test at 16.7, then at 18, 20, 24.... whatever I want..... ..I will not be fixed to any one carb setting, i will adjust as needed...... It is not like I am expecting to tune the carb at average atmosphere then be able to run double the pressure without resetting my needles........... I will have absolute total control over the pressure of the atmosphere with great accuracy..i can increase it only 1 PSI over standard all the way up to 150 PSI......... 1 PSI over standard is a smaller difference then going from sea level to 5000 Feet above sea level..... these engines tune quite fine at all altitudes...... I will not be doing anything different then running the test 5000 feet below sea level...just a heavier atmosphere...... You will see there is no real limit to the density of the atmosphere these engines can run, the whole loop scavenging system doesn't stop working the moment you go over 14.7 PSI LOL..... it will work just the same at 15.7 PSI as it does 14.7 PSI and it will work just the same at 18.7 PSI and so on and so on.... As we increase pressures I am sure we will have little tweaks to adjust.....however I have full control over my fuel pressure and fuel flow so its no issue... by encasing the carb we will eliminate any ballooning issues with the carb boot... Anyways its a very simple test that will definitely put a end to all the arguments about how a 2 stroke can't be boosted because the intake and exhaust are open at the same time....you all know what I think of that theory, so I will let it rest for now ! ....

TheKennyKiller

The lengths people will go to just to prove a point. Guys... wouldn't it just be better to agree to disagree? Oh crap, I forgot I was on RCU for a second... Carry on.

Steve108

My Feedback: (36)

Well, unless you increase the air pressure around the muffler outlet too, things will be a little different... but good luck!

supertib

You shouldn't be so fast to start to criticizing this thread.....we are only having a peaceful open forum discussion about an advanced technical subject related to nitro RC's....I don't see any name calling or any other reasons for anyone to complain....... these types of discussions do no harm at all, and in the long run will offer a rich source of technical information your not going to find many other places.......Unlike many others I am actually capable of building and testing the apparatus needed to test the theories of boosting a nitro engine.....If anyone is disinterested in nitro engine theory then they should just not read the thread and allow us other gear heads to do our thing without all the complexity added by unneeded drama....For me this has nothing to do with proving a point, or at least not in the connotation you want to apply ...I am driven to try these sorts of things because it is my passion, my hobby and my business..... Anything new I can try is like a treat for me, as I thoroughly enjoy what I do.......building and dyno testing a way to boost these nitro engines is an awesome project that I would do whether someone was egging me on or not.....A little extra drama on the forums bantering back and forth in good nature just makes the results all that much more interesting..............Just wait guys..... this entire project is going to be interesting for anyone who has any sort of fascination with nitro engines.......The thing you need to remember, that is anyone can make boost work on these engines it is going to be someone like me...I bring a whole pile more experience, knowledge and resource then the guys you see on youtube bolting a RB innovations Supercharger onto their T-Maxx ........... So don't count this theory out untill you take the time to know the players in the game..... What I got planned is a whole different ballgame then what anyone else has done......

supertib

exhaust pressure is easily tuned by stinger diameter....On the dyno I have already tested running the stinger under vacuum....it is not going to be any issue

phmaximus

Who is asking about regulating the boost? I was asking why incase the carby?
That got nothing to do with boost, it's about fuel flow

phmaximus

Ahh my question now, since u reject my idea How is it going to flow fuel if the tank pressure is lower than the manifold pressure?[X(]
I don't think it will. the flow from the Venturi is not that strong, it can't even supply enough fuel ally it self on a non tubrocharged motor

High pressure air allways move towards a low pressure area. If the tank has a lower pressure than where the Venturi is it will blow the fuel out of the carby and back to the tank, I'm very doubtfull that the exhaust pressure will be more than the turbo pressure

One of the reson's that turbo carby cars have a incased caby is so that the pressure inside the fuel bowls are the same as the MAP and allso so they don't have to worry about sealing the carby up from leaks (around shaft bearings is one)
Some are not incased but they incase the top part of the carby and thats where the fuel bowl breathers are therefore equalizing the pressure on both sides of the Venturi.

So all incased and non incased existing blow through carbys equalize the pressure on both sides of the Venturi. Why won't ur setup need that done?

It would be very easy for the non believers to test.

Get a old carby and connect a aig gun with a rubber grommet to the inlet, blow air through it.
U should feel vacuume on the fuel intake tube.

Now cover the outlet with a rubber plug with a 2mm hole In it, that will simulate a running motor with air flowing through the carby and providing u are adding more air than what's escaping out the 2mm hole u will get air flow and be able to pressurize the carby....
U should feel air coming out of the fuel intake tube.... ie reverse direction of the fuel flow.

That test would allso show how the carby slide/throttle plate bearings react to boost, if they leak or not
If they do u could allways do a air seal by applying boost directly to the shaft and bearings.... Well bit more to it than that lol

supertib

I have explained this many times over, i need to ask do you even run a nitro engine ? have you ever used a nitro engine even ? if so what kind of gear ? RTR ? do you even understand how the the fuel system works to begin with ? your making me question if you have any actual hands on experience with nitro engines at all ? as your getting hung up on something that is irrelevant in the system, the tank does not sit at atmospheric pressure at all , it does not matter what the atmosphere is at as the tank never see's it....... the tanks pressure is directly related to the exhaust pressure........ Also...I can easily put the fuel tank inside the plenum if needed............... this is a non issue........ And believe me, when we amp up the output of the engine the exhaust pressure goes right up with the power...these things are air pumps...the more power we make, the more air we pump into the engine and the more exhaust we pump out of the engine... increasing the volume of the exhaust will increase the pressure inside the pipe which will in turn increase the pressure inside the fuel tank.................. i see no need for any one way valve ............

supertib

and why would I encase the carb ? well chances are the entire cabin the engine sits in will be pressurized....so by default the carb will be enclosed..... the exhaust tip however will vent to standard atmosphere... fuel tank can be either inside or outside the cabin......... I Also have a nice gravity feed fuel system from my breakin benches I can use as well....... anyways as I say, fuel supply will be no issue, I have multiple options available to tackle any issues

byrne1157

All I'll say at this point is, Build 'er up and tell us the results!! I'm anxious to know what happens...

TheKennyKiller

Yeah yeah yeah, I know you guys love to tackle the big issues.

I just think it's funny how far you guys will go to not only one up the other guy but also just to prove yourself right. Even though there is no name calling it's pretty easy to see that there is no love lost between some of the participants in these type of threads. Anyway, seeing how desperate you guys are to prove your point is kinda entertaining so like I said earlier, carry on.

BTW I love getting one star ratings, it's like giving an attention seeking little boy an ice-cream.

Chris Nicastro

My Feedback: (3)

This is an interesting topic so Ill throw in a couple of ideas.

First how much cash are you willing to throw into this project?
Second what is the purpose of the engine, its application?

Watching the EDF supercharger video I was thinking of the same concept because its easy to prove the idea. What I didnt see in the video is a simple Y-harness of the Throttle channel to run a brushless ESC. This way the EDF unit will speed up and slow down in relation to the engine.
Next I would try a 30mm EDF unit from GWS and use a brushless 10A ESC on 2S Lipo. Make a simple manifold to adapt the fan shroud to the carb.
Then I would add an external remote needle valve on a 3rd channel so you can adjust mixture. This can be programmed as a mixed channel so as you pull throttle the fuel mixture changes accordingly.

Now you have a basic test rig to prove if the 2C engine will respond to a turbo.

Also depending on the engine you need to know what the CFM of the engine is compared to the CFM of the EDF unit. Doing the math will give you an idea if you can pressurize the fuel / air charge ahead of the crank port. This might require the fabrication of a plenum chamber to pressurize first so the carb and crank can draw from this volume at higher pressure. This is also an opportunity to cool the air in the plenum like an intercooler.
I would bet you can adapt a full size carb flow meter to see what the engine draws.

So personally I would try all of the above before I even attempt cutting metal and designing a turbo, exhaust and intake manifold. All this stuff is off the shelf and easy to get.

Also OS made a fuel injection system for 2C engines but its super expensive and its for a larger engine, just FYI.

phmaximus

a high pressure will allways move to a lower pressure
the exhaust muffler pressure is going to be lower than the boost pressure
What am I missing? Why won't the high pressure move up the fuel line into the lower pressure of the fuel tank?

U know what, there is no talking to u. I thought we could have a normal conversation with out people Belitting each other and without questioning people's experience and knowledge.

Honestly what type of response is that? If u are going to continue to be like that get the hell out of my thread.

If u plan to keep posting, read the first post... Then read it again and again untill u understand it.

I would hate to see this thread shut down because of one person, I would suspect the moderators would simply remove/ban the offender?

I would like for you to continue posting because it's good to talk out ideas but come on mate, u need to pull ur head in

sparky 25

You are worse than a politician at answering questions yourself,

You know what experience supertib has,

What experience do you have with running nitro engines?

phmaximus

Great ideas, all of them, u could even test out draw through vs blow through carbys. If u used a draw through carby, the adapters will increase the plenum at both ends of the ducted fan. Hey u might even get that tornado effect those inline fuel savers are ment to do... Lol

phmaximus

What do u mean? All I want to know is this

a high pressure will allways move to a lower pressure
the exhaust muffler pressure is going to be lower than the boost pressure
What am I missing? Why won't the high pressure move up the fuel line into the lower pressure of the fuel tank?

I did not expect that response, maby I'm reading into it? Who knows

I don't know supertib and his experances, Sorry

I've got loads of experance with lego engines, and once I pretended a block of wood was a turbo that went pssssst..





I've worked for over 5 years professionals as a fully qualified Ford mechanic, and 3 years non preffosesionaly. I've owned and worked on 85 Mazda 626 turbo deluxe sedan, 92 g102 3cyl charade turbo, 92 twin cam 626 turbo, Datsun bluebird 910 L20 custom turbo. I'm now running a 78 Fairlane 302 Cleveland. I've got a ton of experance with petrol, LPG and desiel turbocharged engines. I've even rebuilt 2 Mazda turbos one for my car and one for work. Wow how exciting, eh?

All that is easly proven by looking at my YouTube account of my pic hosting site

As for nitros I've owned a losi xxx-nt Adam drake edition, GV touring car and a revo Platnium, nothing speical.
But I've run maintained and rebuilt them?

Anything els I can help u with? My left foot has a slight ingrown toenai?

don't ya just love these personal questions, But shouldn't we of started with asl? Or at least dinner?

Now your turn sparky... Let us be free and happy and share each others experance with IC motors... Man I can't even read that with a straight face lol

phmaximus

Im sure supertib knows his stuff when it comes to nitro motors, I'm not denying that.

I'm just asking a simple question and had a simple test for someone to do. Nothing to it.

I thought I had explained my opinion on why I think there would be a problem with the fuel system in some detail that should of been easy to follow.
If someone can explaine how the fuel is going to overcome the boost pressure and flow out the Venturi
Or preform that simple test I'll be happy and stand corrected. Hey I'm not perfect,

sparky 25

My god it wasn't an invite to dinner,

Sorry to disappoint,

you should get that toenail seen to,

So you have a book on Holley carbs, fantastic,

Thought as much on your nitro experience.

phmaximus

Here this might help u understand what I'm on about

Read this, great article
http://www.xfalcon.com/forums/index....w-through-101/

Now for that basic carby to be setup for a draw through turbo setup, the boost pressure needs to reach the fuel bowl, the floats need to be changed so they don't collaps under pressure, and the fuel in pressure needs to be higher than boots pressure.
Without the boost pressure getting to the fuel bowl there would be NO flow of fuel through the jets, metering block and out the Venturi
Without increasing the fuel pressure more than the boost pressure u won't get fuel flow into the fuel bowl

For that carby picture it as a nitro fuel system,
the Venturi is the carby
The fuel bowl is the fuel tank
The jets are the HSN
And the fuel inlet could be the muffler pressure to push the fuel out of the fuel tank

So wouldent the fuel tank need to be pressurized just like a fuel bowl on a real carby, so it can flow fuel out the tank, down the fuel line(metering block), through the HSN(jet) and out the carby(Venturi)
Otherwise the fuel pressure will be lower than boost pressure and won't flow, at best connecting the boost pressure to the fuel tank will make the fuel pressure the same as boost pressure but ideally it needs to be more.

With out a one way valve on that boost line to the fuel tank, under idle, the muffler gas that pressurizes the fuel system off boost would leak into the intake and reduce fuel pressure causing a lean conditions

Now say we run that boost line to the fuel tank, we allso need to stop that boost pressure escaping out the hose from the tank to the muffler, the boost WILL escape because the boost pressure is higher than the exhaust pressure. A one way valve should be fitted to let exhaust pressure into the fuel tank off boost, and to stop boost pressure leaking out the exhaust under boost

Seriously does this make sence?

phmaximus

Do you understand the above post?

[&o]

I'll go to the dr. Soon I promise

How's the book even has color pictures! Crazy I know

Yes I thought as much about my nitro experance too, 3 were enough for me, can't say I'm really interested in nitro engines that much these days, I'm getting into 1/5 scale petrol 2 stroke motors lately... Hay how's this for lack of experance, part of my apprentaship was 2 stroke engines... No kidding, bet ya never thought of that, here is the crazy part, did u know I'm fully qualified to work legally unsupervised on 2 stroke engines as a qualified trades man? My qualifications are accepted in most English speaking contraries too...
Owwww ner ner, can u say that? [8D]

sparky 25

Take that little picture from your book?

Lad seriously you want to talk mechanics to me, your in way over your head.

supertib

Phaximus...the fue tank is not at lower pressure..... the fuel tanks always sits it a higher pressure then atmosphere dude to the exhaust gasses being pumped into it..... Even at idle if we pull the pressure line off the tank immediately loses = pressure and the engine leans out...............if you actually owned a nitro car you would know this....

supertib

Are you really this ignorant of a person ?

supertib

And no, the fuel tank is not the float bowl..we are dealing with 2 very different styles of carbs here....... no carb has a pressurized float bowl..... these nitros run off a pressurized fuel tank..........