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Engine basics => Engine set up tips => Topic started by: Craig Beck on April 10, 2017, 10:41:09 AM
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So i just bought a brand new Big Mig 40 by Norvel. I got a super deal and im really excited. I seen that Sig sells them too. Has anyone used these for control line? What size venturi do they use with what spray bar set up? Can i get a tongue muffler for it? If you havent seen one of these, awesome design and superb machining. I cant wait to run this thing..
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I'm also interested in how this works out for you.
I think they also have a gas version, that could prove interesting.
I've found most c/l folks to be follow-the-leader types though, so unless someone before you that is recognized give it his "stamp of approval", you're probably going to be met with some negativity. If I were you, I'd ignore that to some degree, and forge out on your own, and see what happens.
The Norvel people have been very helpful for conversion for my .061 Big Mig, so you might check with them first.
Good luck. I hope it works well for you.
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Thanks Chris. I agree. I think i need to give Leonard at stuka stunt works a call. He turns any venturi a guy could want out of aluminum bar stock. Heck i could just take the engine to him. He is only an hour drive from me. He can hook me up and get it done right. Im building a fancherized twister, i think this engine will fit it nicely. ..
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If you can also get him to make you a tongue muffler, you would then be all set!
I'll bet that NV engines might make an venturi for it already. The only question would be how big the throat is.
On my little engine, the NVA was the same for the R/C carb as the venturi, so that was that....
Please let us know how it works out for you. They look to be well made machines, but who knows what the porting is like and how well it will work for U/C....
I have my fingers crossed though, for you!
R,
Chris
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Craig, not sure how much they cost, but nv engines has a "muffler extension" on their website. Two of those butted together with an end cap would make an instant tongue muffler, if you can't find a victim to sell or make you one...
I would have posted a link, but Mr McAfee doesn't like the NV Engines site on my phone....
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Wow Chris. Thats smart thinking. Ill keep that in mind. That would definetly work. Thank you
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It's not ideal, but it would work...
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Big Mig 40 CL version lists for $114.99. Neat looking venturi NVA. There is also an AX 40BB CL Revlite that lists for $124.99.
http://www.nvengines.com/index.php?option=com_virtuemart&Itemid=65
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I also pinged nv engines, and they said we could get that gx-40 in a u/c version.
That would be very interesting. No ignition+ 60% less fuel....
R,
Chris
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The Norvel engines had a reputation for coming from the factory with machining chips inside. I don't know if the "new" NV engines are like this or not. I'd never suggest this for an OS or Enya, or even for a good used engine of any brand, but -- pop the backplate off and take a look; if you see anything in there that shouldn't belong then clean the engine up before you run it.
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I will open it up and check for metal particles. I seen where they had the c/l venturi and needle assembly from the factory i can buy for 26.00. I think that will be my next investment. Lol
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Not sure where the metal chip reputation came from, I have quite a few of them( a bunch) , never saw that problem. I guess any new engine could have chips.
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It's probably urban (stunt) legend....
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The Norvel engines had a reputation for coming from the factory with machining chips inside. I don't know if the "new" NV engines are like this or not. I'd never suggest this for an OS or Enya, or even for a good used engine of any brand, but -- pop the backplate off and take a look; if you see anything in there that shouldn't belong then clean the engine up before you run it.
In their company blurb Norvel state that " Then our highly skilled technicians assemble the engines and then test run each engine at the factory and test them both hot and cold before delivering the final product to you."
So if there was any rubbish internally its all a bit too late because it already has been run and flushed out.
Perhaps this is the 'new' way of suppliing the engines (get rid of the evidence before the public can witness it!)
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It's funny how a rumor becomes "fact" in forums.
Tim stated that the Norvel engines "had a reputation" for having machining chips inside.
Others stated that this was not their (first hand) experience.
I'm not sure how a rumor trumps factual first hand experience, but, to each his own....
When I get a few extra bucks from finally working some OT again, I am likely to buy a GX .40C/L.
I'll be sure to report back if I find any chips inside, although I am sure I will be lucky in this experience.
:-)
R,
Chris
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Craig Beck-
Did you ever get the NV engine going for C/L?
I'm getting ready to pull the trigger on a GX-.40, but have some questions about the venturi and muffler I emailed to them.
For all the engine veterans out there-
Am I correct to assume that the venturi might be smaller for a gas engine than a glow, since the fuel consumption is notably less, or is the mixture leaner and that is handled by the NVA?
Thanks in advance for that.
R,
Chris
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Regardless of what type of fuel you use (methanol v petrol) all the needle valve does is to adjust the fuel flow for the optimum air/fuel ratio. Because of the huge difference in air/fuel ratios between these two types of fuel the needle only needs to be opened about half as much for petrol so adjusting the needle to suit petrol will be more critical unless the needle has a much finer taper to allow for this. As for venturi size, obviously a smaller venturi restricts airflow which has to reduce the power. Power loss with petrol is compounded by the fact that with a correct mixture it has only about .7 the heat release off methanol which, to me, would indicate the use of a larger venturi for more mass airflow to make up for the poorer fuel. Another thing that might need some attention using petrol is that because of the much lower fuel flow then there's also a much lower flow of oil into the engine.
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Thanks. So it's just a leaner fuel air ratio, and that's handled by the needle...
Since this is a dedicated gasoline engine, I would assume by design they would use either fine threads, or a shallow angle needle, or both.
I'm intrigued by the smaller tank I'll be able to use.