I have just purchased a extreme flight Mini 3d that I will soon be assembling, I am looking for a good power plant for this little machine, something light, powerful, and most of all dependable. It doesn't have to be new, in fact I would almost prefer one that is a little used, and well broken in as they seem to be more reliable. I don't want to have any deadstick problems. I have a Norvel .15 AME but it is not as reliable as I want it to be yet, still too new!
I have been looking on Ebay and in the market forums but have some questions
I am considering an O.S. .25 but what is the diff. between a O.S. max FX and FP
Also anyone ever use a HB motor (german made)
any other sugestions that might be helpful? I want to keep it as light as possible!

Chris

If you have the HP use it next choice 25 fx (BB engine) the FP is a plain bearing I have a couple of magnum 25s great runners
also not too many $$ martin
the mags areBB twin needles and back off angle set on main needle ( they are also diesels with davis heads)

Another option is to look at one of the many .32-.36 engines that are effectively a bored-out .25. While your average .25 will spit out 0.6-0.7HP, the .32-.36 ones are often 1HP or more.

If you do want to stick with a .25 though, the Thunder Tiger 25GP is a nice little plain-bearing motor that's reasonably powerful, quite light, extremely well-mannered and ultra-reliable (all good traits for 3D stuff).

I've not had a Magnum but another guy in our club does and, while it's reasonably peppy, it's not always "on song" whereas the TT engines are ultra-reliable. You might also want to compare the power-to-weight ratio of something like the TT25GP with oen of the ball-bearing equivalents. The 25GP is often superior because those BB engines can be quite heavy for only a minor increase in power.

The current non-BB engines are typically in the .6 hp range. Thunder tiger GP25 and OS 25 LA are good choices for this class. For a little more money, and weight, you can get one of the BB engines. They are typically .8 hp or better. Examples include Magnum XL-25A, GMS .25 BB ABC, and OS .25 FX.

If you're looking at older engines on eBay, my all time favorite 25s are the OS .25 FSR and the 25F ABC. I've got one of each, that I bought new in the '80s. I flew the 25F in a Modeltech Extra 300 ARF all summer. Not a single deadstick. The FSR does not have as much power, .6 hp versus .8 hp. Amazing how little progress has been made relative to hp, eh?

Another series of light powerful engines are the Webra 32-36 size rated at up to 1.4 HP

The new Webra .25's are GREAT little engines with lots of power. The GMS.25 is pure JUNK, I had two. All I run is .25's

You could always use a 40/46 OS la engine. They weigh about the same as the .25 fx, and they will have more torque than the .25 FX, allowing you to swing a big fun-fly prop. The .25fx likes to rev.

Chris,


The MVVS .28 with the tuned silencer, will out-power similar OS and GMS engines.
And if you shop right, it will also undercut some costs.

The big Webra .36 will out-power it, but will also cost more.

I have Both the OS 25 FP and FX are reliable engines. The FP Is on a Pizza Box right now and and has never quit other than running out of gas when I was having to much fun and lost track. Many, many hrs. on it. Noticeably lighter than the FX.

thank you all so much for your input I saw one engine, an O.S. 32 or 36 I think. it had what looked like an aluminum square around the top of the engine? what is this? is there a purpose for it? it looks like extra weight, what gives?
Anyone got a nice o.s. 25 fx or 32 sx they want to part with ?

Chris

Heli engine, extra cooling.

Isn't the mini 3d a .15 powered plane? If so, why are some of you recommending engines that are 3 times bigger than what's called for (.46)? Wouldn't this be way too much power for this plane?

We have a local guy here flying his with the .25 OS LA

Looks like the perfect engine to me, reliable, light, and cheap.

Still plent of power to do all the fancy 3d stuff. He hovers it in front of himself all day long, and it has plent of power to rocket out of the hover. This is a small plane, it does not need a 25 FX , 32, and definately not a .40/.46.