jester_s1

I see no value in discussing engine options for this plane that no longer exist in the market. Let's not forget the purpose of this thread- to help a nice lady buy a gift for her boyfriend. I agree the OS .46 AX is more power than the plane needs, but I also still say it's the best option among engines that are commonly available in the marketplace today.

JollyPopper

My Feedback: (6)

I was very pleasantly surprised earlier this summer to find that an OS .46LA mounted on a Sig Seniorita was a real delight to fly. I was seriously worried that it would not be enough engine for the plane, but it handled it beautifully. I was even able to do slow rolls and lazy loops with it and this airplane is slightly larger than a Kadet MkII. My Seniorita is even heavier than it would have been in stock form because I added sheeting to the entire plane that was not sheeted from the factory because I did not like the open stick frame as it comes out of the box. I tried the LA simply as an experiment to see if it would fly, and the Seniorita is a bit larger than the MkII in wing span. I am not sure of the difference in weight of the two fully built planes but I suspect that my Seniorita will be at least as heavy as the MkII. I am not saying that the OP should go with a .40 or .46 engine; I am simply saying that a .46LA is very capable in the Seniorita even with the additional weight of full sheeting. There is also a lot to be said of a plane with more than enough power if the guy really wants to wring it out, but is not an absolute necessity to make it fly nicely.

jaka

Hi!
For most .40 trainers a .46 two stroke ball bearing engine is way too much power for a beginner, that is my experience from 40 years teaching. That is flying at sea level. A much better choice would be an OS FP .40 or OS .FP .46 if the OS .40 isn´t available. A 11x6 is the size of choice for a .40 engine (Plain or Ball bearinged).
For slower flights even 12x4 prop could be used. Best props on the market are APC, RAM and Graupner G-Sonic. Stay away from Master A props (at least from those white tipped ones with blunt tips) as those are noisy and does not "pull" as good as those I mentioned above.

Stickslammer

Good to see that you signed on here as a member. Best of luck to your boyfriend on his first build. A wealth of info and experience here. Here`s hoping that both of you succeed in this wonderful hobby.

Propworn

My Feedback: (3)

First of all as you have gathered this hobby is all about choices. Everyone has a different opinion on every aspect of outfitting/building this model.Its been around, updated and refined over the years and building it exactly as per the instructions will result in a very nice/durable trainer. My advice is to buy the trainer and a gift certificate that he can apply to additional stuff he will need. That way he can choose the color of covering, engine type and size, radio etc. Ask the hobby shop the estimated cost of these items and adjust the gift certificate to what you can afford. Trust me if he has any interest at all this will push him in the right direction. He needs to become familiar with the local club and hobby supply as those will be the primary help he needs.

Dennis

born2build

R/C engines have throttles.

Hydro Junkie

I said that earlier and got shot down. I'm thinking it's and "instructor" thing of some sort

born2build

I started my R/C pilot training back in 1979. My two instructors (one older, one younger) both demanded I learn how to use all four controls simultaneously.
What I don't understand is, why would someone recommend an inferior engine?
My main point is, why buy an engine you'd have little or no use for once you're ready for more aerobatic models? I can't imagine using an O.S. 40LA in a 40-sized pattern ship!
As a bonus, the 46AX is a couple of ounces (I think) heavier than the LA. The extra weight will no doubt be needed in the nose for balance.

TomCrump

There are a few assumptions and opinions, here.

What is inferior in you opinion, may not be, in another's view.

You are assuming that a novice will want to "advance" to pattern flying.

A properly maintained 40 FP can last for a long time. A friend ran 40 gallons of fuel through his, and the only "repair" was to change out a few glow plugs.

There is nothing wrong with pattern flying, but it is only one, of many, avenues to progressing in the hobby. Sport flying is predominant with most modelers. A 40 LA, or 40 FP will power many sport models in an adequate manner.

buzzard bait

And my Kadet II balanced perfectly with an OS 40FP, saving the extra 5.5 oz of the 46BB, and it was in no way inferior for the purpose of training because it started easily, throttled well and gave the right power. Best to match plane, purpose, and engine, not to buy an engine for a plane you don't have yet.

JollyPopper

My Feedback: (6)

My Seniorita balanced perfectly with the OS .46LA and flies beautifully. It is one of my go-to planes when I go to the field. I suspect a 40LA would handle it and will probably try it next spring. There was a time when I would have put a .56 or .65 or .70 four stroke in this thing along with a ton of weight in the tail, but I have discovered that flying them "on the wing" instead of "on the prop" is more satisfying.

Hydro Junkie

But isn't building a plane to "fly on the wing" harder? I'm sure most of us know by now that harder and/or not being explained the "how's and why's" by and "expert" on the internet means that something just plain can't be done. I see, over and over, posts about this or that not being possible since there isn't anyone putting out simple instructions or premade part kits on how to do the project. Then again, I just today got slammed because I posted a comment about making engine cowls for gas scale hydroplanes. My post said, in a nutshell, that if someone was going to make cowls for two of the boats, they needed to make sure they did their research so that the cowls would look right for the configuration being modeled. I got blasted for using the word scale as, all of a sudden, everything had to be EXACT SCALE DUPLICATES to the full sized originals, even though one boat used three different cowls and the second(this being a multi boat team) used at least four or five. The next comment basically told me to sit down and shut up since the guys involved have the time to build multiple boats every year and I don't. I guess this comes back to the norm of forums, if you don't have photographic proof that something can be done, no one will believe or listen

buzzard bait

This is really not complicated. The Sig Kadet goes back to the early 70s. People mostly flew them on 35s and 40s of the day and built them stock...by the thousands. By the many, many 10s of thousands. Anyone who flew RC airplanes from the mid 70s to maybe the early 90s knows how common and popular they were, and how well they flew on any engine within the recommended size range. It's still a fine choice and a wonderful gift. It will fly on any reasonable source of power.

Jim

Propworn

My Feedback: (3)

I hope your boyfriend will hook up with a club/instructor rather than attempt to fly this on his own. Yes lots of us learned to fly on our own but we also became experts on repairing long before we became good pilots if you get my meaning.

This is the perfect time to get him introduced to a club and he will usually find lots of help locally. The local instructors will be able to advise him on an engine/radio that they have had success with. He might even find a mentor or two who can help/advise on the building and outfitting of his model.

Depending on the hobby shop they can be great resources but remember they are there to make a sale first. Hobby shops range from great to those that will try to sell you anything they can. Experience flyers at a club will be able to tell you not only which hobby shop is good but which sales person is best to deal with.

I gather with Christmas just around the corner this is to be his gift. Very nice.

Dennis

born2build

I never said a 40LA would not power a Kadet well. I never said the 40-sized pattern plane must be used to fly pattern only!
All I'm saying is that the 46AX is a far superior choice overall. The LA series was designed down to a price point. The AX series was designed up to a standard. And pattern ships fly so well, they make great sport models.

jester_s1

Ok guys, I think the topic has been sufficiently covered. Pretty much any current production 2 stroke engine between .40-.50 will do just fine as an answer to the original question.

To the OP: We haven't heard from you in a while, but if you are still monitoring the thread you've seen what's both good and frustrating about our hobby- the people who do it. We can be an opinionated bunch, but generally are enthusiastic about helping new people get started. I hope your boyfriend enjoys his gift.

Tom Nied

My Sig Kadet Senior that I learned how to fly RC on has a Thunder Tiger GP .42 on it. I still have it, and it's still flyable. Think I'll pull it out this year just for fun. Plain bearing TT GP 42. Flew great and really just sipped the fuel. One thing great about a Sig kit is that they really give a lot of good info in the manual. A Sig Kadet can be a blast to fly. I use to take it real high and try to fly inverted. It always wanted to fall off and right itself, but it could be done. Slow flight, it's great. Mine is only three channel (throttle, elevator, rudder), but I learned just fine on it. Windy days, not a good idea. The Kadet Senior is a pretty big kite.