What is best motor for 1/12 miss llamar hydro
#26
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Sounds like the right people are here. Please help me out run these new brushless boats. Grudge racing co-workers and need fastest setup possible on a low budget. Need to know prop, fuel and motor to put in 1/12 hydro.
#29
Here are some budget upgrade engines to offset the sport .15 engine.
http://www.ebay.com/itm/VERTEX-18-NITRO-BOAT-MARINE-ENGINE-FLYWHEEL-COUPLER-/310894442434?hash=item4862c0b7c2:m:m3svV963b4d7NFG GppXMwSA
VERTEX 18 NITRO BOAT MARINE ENGINE FLYWHEEL COUPLER
http://www.ebay.com/itm/NEW-SuperTig...42403793&rt=nc
.18 Inboard Marine Engine w/Super Start SUPG0718 SUPERTIGRE
This may be a tight fit over the existing .15 engine lots of power will for sure make it run
at its physical limits based on the hydro's size.
http://www.ebay.com/itm/Team-VTX-PLU...2-QijKBq91svPw
Team VTX PLUS 26 Nitro Marine Engine w/ Flywheel & Collet 3/16" 4.7mm
http://www.ebay.com/itm/VERTEX-18-NITRO-BOAT-MARINE-ENGINE-FLYWHEEL-COUPLER-/310894442434?hash=item4862c0b7c2:m:m3svV963b4d7NFG GppXMwSA
VERTEX 18 NITRO BOAT MARINE ENGINE FLYWHEEL COUPLER
http://www.ebay.com/itm/NEW-SuperTig...42403793&rt=nc
.18 Inboard Marine Engine w/Super Start SUPG0718 SUPERTIGRE
This may be a tight fit over the existing .15 engine lots of power will for sure make it run
at its physical limits based on the hydro's size.
http://www.ebay.com/itm/Team-VTX-PLU...2-QijKBq91svPw
Team VTX PLUS 26 Nitro Marine Engine w/ Flywheel & Collet 3/16" 4.7mm
RPM Range 3,000 - 42,000
Last edited by Pond Skipper; 02-16-2017 at 07:43 AM.
#30
I've seen several different motors put in those Pro Boat hulls. The OS .18 used to be an option but I think they were discontinued.
Upon doing some research, I have found the following:
Super Tiger .18 http://www3.towerhobbies.com/cgi-bin...?&I=LXWPH8&P=0
Novarossi .15 http://www.novarossi.it/2012/index.p.../t-mx15pr.html
CMB 21 http://www.cmb-motori-italia.com/21vac-en.html
While all of these should work, the NR and CMB may be too powerful for the Llumar. Something else to consider is that the NR and CMB are race motors and cost considerably more than the ST
No matter which one you buy, they are all much less expensive than the $950 one I have to get for my gas boat, shown below
Upon doing some research, I have found the following:
Super Tiger .18 http://www3.towerhobbies.com/cgi-bin...?&I=LXWPH8&P=0
Novarossi .15 http://www.novarossi.it/2012/index.p.../t-mx15pr.html
CMB 21 http://www.cmb-motori-italia.com/21vac-en.html
While all of these should work, the NR and CMB may be too powerful for the Llumar. Something else to consider is that the NR and CMB are race motors and cost considerably more than the ST
No matter which one you buy, they are all much less expensive than the $950 one I have to get for my gas boat, shown below
Last edited by Hydro Junkie; 02-16-2017 at 08:01 AM.
#31
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whatever motor you select to use just make sure there are plenty of spare parts available for it as several of the top r/c glow manufacturers no longer exist. example; how many 21 marine race engines are now on the market ? CMB / NOVAROSSI / ? ? ?
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So I bought the NR t-mx15. Trying to get it setup and wander about the flywheel and cog. I took the ones off my dynamite and the flywheel doesn't fit well. Do I need the fly wheel. How can I get the parts I need asap.
#33
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Yes, you absolutely need a flywheel. You may have to remove the spacer plate to get it to fit properly. I think that there's a conical piece on the Dynamite that you're going to need also. If you need a flywheel, the O.S. Engines 1-D works great and can be gotten from Tower Hobbies.
The CG will not change as the boat is already tail-heavy.
The CG will not change as the boat is already tail-heavy.
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I don't see the 1-d on towers website. What is the purpose of the flywheel. Ron, Boy I need you here. Wanna just send you the boat and parts and let you get this dialed in. Can I bore the dynamite out a little so it slide on the NR bolt
#36
The flywheel is definitely needed. What is does it twofold:
1) It smooths out the engine by maintaining the momentum provided by the burning of fuel pushing on the piston. Otherwise, the engine would have a pulsing output and eventually could stop running all together.
2) It prevents the engine from overspeeding and self-destructing every time the prop leaves the water. Just like a car with a manual transmission, any time the prop comes out of the water or, in the case of the car, the clutch peddle is pushed, the engine has no load on it. If something isn't holding the engine back, the engine will continually speed up until it flies apart. In the case of the car, you pull your foot off the accelerator peddle, allowing the engine to slow down while shifting to the next gear. Since you can't react fast enough with the boat, especially when it's on the backstretch 75+ feet away, something else has to do this for you, in this case, the flywheel. Since it takes a bit of time and power to get the mass of the engine's flywheel to increase it's speed, that gives you, as the driver, a chance to back off the throttle, like in the car example, or the prop time to get back into the water, reloading the engine before the engine blows up.
Now is where the argument comes up, "Then why doesn't an airplane engine need a flywheel? They are basically the same design." which is true, unless you really start looking at the way the marine and aircraft engines are set up. Just for giggles, we'll cover that in the next post, rather than muddy this one up
1) It smooths out the engine by maintaining the momentum provided by the burning of fuel pushing on the piston. Otherwise, the engine would have a pulsing output and eventually could stop running all together.
2) It prevents the engine from overspeeding and self-destructing every time the prop leaves the water. Just like a car with a manual transmission, any time the prop comes out of the water or, in the case of the car, the clutch peddle is pushed, the engine has no load on it. If something isn't holding the engine back, the engine will continually speed up until it flies apart. In the case of the car, you pull your foot off the accelerator peddle, allowing the engine to slow down while shifting to the next gear. Since you can't react fast enough with the boat, especially when it's on the backstretch 75+ feet away, something else has to do this for you, in this case, the flywheel. Since it takes a bit of time and power to get the mass of the engine's flywheel to increase it's speed, that gives you, as the driver, a chance to back off the throttle, like in the car example, or the prop time to get back into the water, reloading the engine before the engine blows up.
Now is where the argument comes up, "Then why doesn't an airplane engine need a flywheel? They are basically the same design." which is true, unless you really start looking at the way the marine and aircraft engines are set up. Just for giggles, we'll cover that in the next post, rather than muddy this one up
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So should I drill the fly wheel from the dynamite to thread on the bolt that screws into the crank on the NR? And should I remove the nut that hold what I think is the spacer tight?
#39
As promised, here's the "Why doesn't an airplane engine need a flywheel?" post.
Just like the flywheel above, there are two reasons why the aircraft engine doesn't need a flywheel:
1) It already has one, the propeller. Due to the length and pitch of the prop blades, it exerts a load on the engine any time it's running, preventing it from overspeeding. Obviously, too short of prop or too little pitch won't load the engine properly but, by the same token, neither will to much length or pitch. Too much of either will overload the engine, causing other problems that I won't to into here
2) Operating Range!!!!
This is something that most don't have a clue about. All engines have an operating range where they work the best. For example:
a) a diesel engine in a semi-tractor is tuned to run best between 800 and 1400 RPM
b) a V-8 in most cars are tuned to run best around 2000 RPM but, conversely, have the most power between 3500 and 4500 RPM
c) a 4 cylinder engine runs best around 3000 RPM but have the most power at closer to 5000 RPM
Obviously, all those numbers are generic, but well in the ballpark. They do, however illustrate my point.
Using a .20 sized engine, we get the following:
1) A marine engine will max out between roughly 30K and 50K, depending on manufacturer and set up in the boat
2) An aircraft engine will max out between 15K and 20K, depending on the manufacturer and set up
Why the difference in RPM ranges? Very simply, the application and the prop. Application means is it in a car, boat or plane. Nothing confusing there, so the big difference has to be the prop.
With a boat prop, you're pushing against a very stiff and heavy medium, your standard everyday water. Due to this, the blades are short and wide, giving the best bite into the medium it's designed to work in.
An airplane, however, is designed to fly in a much thinner medium, air. The prop, therefore, has to be optimized to work in this as well. The blades are fairly long and thin when compared to boat props. This does, however, bring up it's own problem. That problem is, in a nutshell, the speed of sound. As a prop blade tip approaches the speed of sound, it stops pulling efficiently. To prevent this, aircraft engines are tuned to run at speeds low enough to keep the blades pulling efficiently. Therefore, larger engines using larger props run slower and slower as the size of engine and prop goes up
Just like the flywheel above, there are two reasons why the aircraft engine doesn't need a flywheel:
1) It already has one, the propeller. Due to the length and pitch of the prop blades, it exerts a load on the engine any time it's running, preventing it from overspeeding. Obviously, too short of prop or too little pitch won't load the engine properly but, by the same token, neither will to much length or pitch. Too much of either will overload the engine, causing other problems that I won't to into here
2) Operating Range!!!!
This is something that most don't have a clue about. All engines have an operating range where they work the best. For example:
a) a diesel engine in a semi-tractor is tuned to run best between 800 and 1400 RPM
b) a V-8 in most cars are tuned to run best around 2000 RPM but, conversely, have the most power between 3500 and 4500 RPM
c) a 4 cylinder engine runs best around 3000 RPM but have the most power at closer to 5000 RPM
Obviously, all those numbers are generic, but well in the ballpark. They do, however illustrate my point.
Using a .20 sized engine, we get the following:
1) A marine engine will max out between roughly 30K and 50K, depending on manufacturer and set up in the boat
2) An aircraft engine will max out between 15K and 20K, depending on the manufacturer and set up
Why the difference in RPM ranges? Very simply, the application and the prop. Application means is it in a car, boat or plane. Nothing confusing there, so the big difference has to be the prop.
With a boat prop, you're pushing against a very stiff and heavy medium, your standard everyday water. Due to this, the blades are short and wide, giving the best bite into the medium it's designed to work in.
An airplane, however, is designed to fly in a much thinner medium, air. The prop, therefore, has to be optimized to work in this as well. The blades are fairly long and thin when compared to boat props. This does, however, bring up it's own problem. That problem is, in a nutshell, the speed of sound. As a prop blade tip approaches the speed of sound, it stops pulling efficiently. To prevent this, aircraft engines are tuned to run at speeds low enough to keep the blades pulling efficiently. Therefore, larger engines using larger props run slower and slower as the size of engine and prop goes up
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Well I got everything installed. Hopefully my flywheel set up works properly. Modified the dynamite parts. Will the engine get easier to pull after it runs once or will I need to put the kwik-pit electric start backplate.
#43
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There aren't many in that size. Aeromarine offers the Mean Machine which originally nitro powered but more are being sold now for electric use. The Sprint Cat .21/.45 is the same hull but with a heavier lay-up. IF you can contact anyone at Aeromarine or you're better off going through a dealer, ask for one with a light lay-up. There's plenty of room in those.
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