brunofporto

I started this topic to focus the discussion aboutEvgeny-arm's mods with the carburetor of the Evo10GX engine.

Evgeny-arm's original posts and discussion at:http://www.rcuniverse.com/forum/m_11...57/key_/tm.htm

brunofporto

brunofporto

What about dimensions?



How do you fix the idle needle to the body (left image)?

What is the tolerance (difference between hole and needle diamenter) between the hole and the needle H7?

I see you did technical drawings (blueprints) of the components, do you have a photo of the drawings?

skip1320

Always the walbro option,no tweeking,crappy muffler,timing set to[runs good}slaped together,other mods look great though http://www.youtube.com/watch?v=jT7Ct...yer_detailpage

brunofporto

AA5BY

Or.... just plugging the end of the spray bar.

flyinwalenda

My Feedback: (5)

When can we see a video comparison of the stock engine running with realtime data versus the engine running with the added mods with realtime data? Pictures and drawings are nice and all but the proof is in the pudding , so they say.

AA5BY

My pudding has not had any dieing problems and idles fine, but as mentioned previous, that may be due to running a 14" prop.

irocbsa

My Feedback: (12)

Now don't go and drag pudding into this.

[email protected]

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so much talk on this engine why cant to maker see all this and fix the engine iwant a engine to run good when i buy it not have to repair it as soon as i get it think ill call the company and see what they tell me

flyinwalenda

My Feedback: (5)

I believe along with the majority of users that the engine runs fine as-is . Biggest complaint is the muffler. You can't please everyone and some won't like it because(insert personal reason here). Others (like in this post) will want to try and improve it to satisfy themselves. Great, but I and others would like to see some videos of the engine running with the mods to see what all the hoopla is about.

[email protected]

My Feedback: (1)

i have seen videos of the engine running all looks good to me

AA5BY

The engine runs well for me.

I don't even know that the carb design in fact fuel dumps as suggested and am somewhat doubtful that fuel collects in the idle bar. Even if it does and is a problem, a fix is simpler than making new carb parts.

jspauld2

oneaew,

What Evgeny is doing is tweaking the carburetor for what he wants. When we have run these engines here for testing and after testing, we haven't had a problem maintaining an idle around 2000 RPMs. This all depends on your idle screw setting, but should be obtainable. Evgeny is more particular about this and prefers to tweak it to his feeling.

We are of course monitoring the situation and continue to perform testing to ensure that we bring the highest quality product to market. All of the comments (good and bad) are noted.

AA5BY

I've noted the positive statements about the engine but have also noted that some have concluded the engine has problems simply based on the rhetoric about needs for modifications. Once again, I applaud the efforts to refine the design towards perfection, but suggest that most sport/scale users do not require perfection.

I've previously outlined that my engine has suffered no dying problems, in fact quite the contrary... it is more resilient to keep running when compared to glow engines. It has been months now since I tached the idle RPM's and I don't recall what the number was, but can say without hesitation that the idle is sufficiently slow that the model does not roll at idle and slows very well during landings and does not die when landing. Again, my success may be due to the APC 14x4 prop.

As to a simpler fix for the possible fuel dumping, simply plug the end of the spray bar with a brass rod and solder or insert a dob of JB weld. There could be many variables in place such as comparing a fast against a slower throttle servo. Maybe my throttle servo is simply too slow to cause the effect that a faster servo might?

edit note: I'm not an expert on carburation. When I suggested an easier fix would be to close the end of the spray bar if fuel dumping when closing the throttle was an issue, I might have overlooked that the idle bar might in fact serve a secondary positive effect beyond the idle metering. It is possible that fuel does collect in it and then serves as an acceleration reserve when the throttle is opened quickly, thus helping to avoid spool up stumble and a required too rich of idle setting.

If that is the case, Evgeny's design does not provide for such. I simply say... I don't know if the idle bar is intentionally designed to provide the spool up dump or even if fuel collects in the idle bar. I'm back tracking my words however and wouldn't close the spray bar end off without an expert suggesting it is ok.

There are several engine experts among modelers and perhaps some will weigh in on the question.

[email protected]

My Feedback: (1)

thank you

AA5BY

Evgeny.. I would never suggest that you are not knowledgeable. I understand that you have space constraints where you fly and when I compare my first landings with my 10GX powered plane with a 11x6 prop screw to those now with the 14x4 there is great contrast and the plane lands much slower.

Above I provided an edit to my previous post saying that I don't know if fuel collects in the idle bar and that if it in fact serves a positive purpose during spool up as a static accelerator pump. If so, my suggestion to close off the spray bar would be poor advice.

I simply do not know.

edit... sport flyers are generally more interested in flying than refining an engine. They wish for general reliability out of the box where their focus can be on the flying.

mattnew

My Feedback: (2)

I'll take some pics with a tachometer this weekend and post a video as well.
I'm honestly not sure where mine is at rpm-wise with a 12x6 but I know a couple things...Its possible its over 2500... we'll know for sure soon enough.
Idle is below stall speed... meaning the engine isn't getting in the way of slowing down.
It won't quit on transitions.

brunofporto

And that is why my next engines will be by Evolution

[email protected]

My Feedback: (1)

thank you happy flying

AA5BY

Idle rpms were checked today with numbers ranging from 1800-2000. Got a couple of blips in the 1700 range and a couple in the 2100 range.

Turk1

Evgeny as I mentioned on other threads repeatedly there is only one flaw in NGH carb. LSN profile cant restrict enough at low throttling zone and it gets overrich due to pump pressure (because there is so high suction on fuel line from crankcase).
If you play only with  LSN profile to gain better restriction down from half open barrel then you will have a great running engine.
Another  solution is,to remove completely regulation system from pump and leave it only as a pump unit.Put a "return  to tank line" using a T conn. at carb inlet nipple.Then having a great running engine.
My observation shows NGH 9 engine has excess suction at low throttle zone resulting regulator to open for excess fuel to carb and LSN is the reason of all.If you can make a perfect LSN profile to restrict suction enough then regulator will not get fake signals to stay open for excess fuel which is the reason of erratic running.

[email protected]

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has anyone thought of returning this engine and getting there money back i see more bad then good for this engine does the company see all the things people write about it

brunofporto

I do not get why would you get to this conclusion.

I read no one saying the engine is no good, by the contrary. I folowed the original topic since the first post and there is no one complaining about it in such way that would justify returning the engine. People only say that the engine is good, I say the engine is good! and I am having a LOT of problems with the original muffler, but the engine is perfectly nice.

I do not want another engine and would buy another one with no doubt! It works as advertized and is as easy to use as any glow. And it pays itself if compared to a glow engine due to the lower consuption and fuel price.

THIS TOPIC IS ABOUT MODS AND TWEAKS and not complains of the engine.

Do not mix things.

I love this engine but I also like to tweak things to have specific performance improvements.

[email protected]

My Feedback: (1)

to when they say they all the things about settings the neddle valve and so fort is a complaint