just ordered a "katana" kit.... was thinking on engine..
i have a brand new OS 120 "twin" 4 stroke... in the box .. think it will be way under powered>? should i step up and get a 160FX or (even more cash) a gas motor>? (3w-24) ... coments,,, ideas>?

What kit did you order?
What type of flying do you plan on doing?

I have the Creek Katana with a 3W24 and I love it.It 3D's and all around flies great.Could be a little lighter,but I am happy with it.

Hank

i ordered a plane from giantscaleplanes.com

http://www.giantscaleplanes.com/Katana_72.htm

this is one of my first planes of this size..so its sort of new to me .i have done quite a bit of flying of .40 and .60 planes and fly a friends 27% extra some.
and i fly choppers as well.
but i am not much for flying anyones planes of that caliber and money...unless they are mine..not my style

i sport fly and 3d some.. and like to go fast.. i am just kicking around ... engine idea`s ...not sure what i want...
like i said.. i have that twin 120...new in box... figured i would try it..most likely will not be as snappy as i would want...
most of my stuff to this point have been 2 strokes..

I say if you have the money,gas is the way to go.There are some really nice small gas engines available now.I really like my 3W24 alot.A little cheaper is the OS 160,but you'll have to put a pump on it to get it to run right.That motor will fly the crap out of that plane.If you want to go 4 stroke,my suggestion would be a Saito 150 or 180,or a YS for more money.
I have seen thet plane and it is very nice.I like the airfoil tail on it.Wish mine had it.
Good luck with your decision.It's going to be a tough one.

Hank

PS: Just some food for thought.Gas is a little more expensive in the begining,but actually cheaper in the long run.$1.50 a gallon plus $2 for oil vs. $10 for nitro.

Not to mention the money you'd save on paper towels.

I ordered the Katana S from Chief...it's the same as the one at GSP...just cheaper...and currently out-of-stock. I'm sure that it will be worth the wait. I am going to (over) power mine with a ZDZ40RV, and from what I've heard from others it will be super.

-Tom

anone put a gas engine in this plane, if so, what size..lookin into getting a gasser about this size..any suggestiond for a gas engine????

I have the Gsp Katana with a Saito 180, love the engine but not the amount of fuel it uses. I just bought an RCS 180 gasser for it. There is a guy on another thread ("CRAZY HERB" screen name) he has an RCS 140 gasser on a Hangar 9 Edge 540 and loves it. He just ordered the GSP Katana and is putting the RCS 140 it I think. I think gas is the way to go but be ure to beef up the firewall.

I would definitely recommend the ZDZ40RV. It's about the lightest gasser of this (40cc) size and will have more than enough power.

-Tom

Guys remeber this is a 72" plane. gas is great, Ive got 3 but this plane should max out at 12 lbs if you want gentle landing charecteristics. I have trouble believing it would be lighter than 13 with a 40 gasser. I would love a good flight report on 3d stuff. I have an OS 160 looking for a home

Hi Tom! How's that gear holding up?

There's another guy around RCU that I spoke to in depth about the GSP Katana. He said that with a ZDZ40 his weighed slightly over 11 lbs! I was originally intending to use a 160fx with a pump, but he convinced me that the ZDZ40 was the way to go.

The OS 160 requires lots of fuel (20 oz) and a mount. By the time you figure the WET flying weights of the plane powered with the OS 160 verses the ZDZ40, you're only looking at a difference of about 6-8 ounces.

I'll certainly give a weight and full 3D report whenever I get mine going. The engine should be here before the weekend and who knows when the kit will show up...might be three more weeks. Whatever happens I'm going to try to shed every gram that I can from the plane...no smoke, light batteries, etc. Should be interesting!

-Tom

I've got one of the (previous generation?) Katana ARFs from Creek Hobbies. DIfferent vendor, same plane.

Several people have reported that it takes 14 - 18 oz. added to the nose in order to balance the plane when set up with an OS 1.60, Bisson pitts muffler, perry pump and a GP adjustable mount. (Rudder servo in the fuse, elevator servos in the tail.) RTF weight is 12 lbs.

I did some quick math... my FPE 2.4 with the stock muffler, upgraded CH ignition and an 1100 mAh nicad weighs the same as the OS/muffler/pump/+15 oz examples.

Guess which route I'm taking

Good point v1. I forgot to add that the guy I talked to said that his balanced perfectly with NO LEAD with the ZDZ40RV. The GSP Katana is already set up for three servos in the tail. The rudder servo mounts in the middle of the fuselage and the kit includes an aluminum double (full) arm so that both ends protrude out the sides of the fuselage. If you look at the picture below you can clearly see this.



But how in the heck do you get that servo in there? And look at that high quality hardware would ya? I don't think so....

I plan on using Futaba 9402s for the three tail servos and maybe the same for the ailerons...if I can find two more. Either that or I'll get some more Hitec digis.

Woo hoo! I'm stoked about this plane!

-Tom

What about a DA 50???

Too much power??

meh, probably..

A DA50??? And I thought I was nuts!

Seriously, I think the ZDZ40RV will be too much...the DA50 would most likely be WAY too much. I would be fun to have straight-up drag races though! heehee

-Tom

Keep this thing as light as possible and put an OS 160 in it . It will need a $25 pump and it will be the sweetest running engine you own. Prime with about 5-8 flips and put on the glow... starts on the first backflip. Economy? 16 oz tank yields 10-12 min flights easily. Messy, no. Only a slight film on the belly after a day of flying, this aint your 46 FX. Uses $10 a gallon common fuel. A 40cc gas may have a slight edge on power but will be 1.5 to 2 pounds heavier. If its tail heavy, get those servos out of the tail! I'm not down on gas but planes this size need all the help they can get to stay as light as possible. 27% planes are the smallest in my opinion to run gas unless wing loading is not a concern. I think gas' power to weight is too small for the small planes. I know there are a lot out there that fly well, I'm just a "light" freak, and the difference in flight characteristics is night and day.

I spoke to a guy that has the GSP Katana with a ZDZ40RV and he said it's slightly over 11 lbs.

I agree with you wholeheartedly...lighter is definitely better. I originally wanted to try an OS 1.60 with a Perry pump but was steered towards the ZDZ.

How do you figure? When you add everything up the difference in WET flying weight is only a few oz.

Here's why:
ZDZ40RV w/ignition, switch, 720mah Nimh pack, Pitts muffler, spinner adapter, prop washer and bolts:
61.1 oz (I just weighed mine with a digital scale)

OS 1.60fx: 33 oz
Pitts muffler: 7 oz
Mount: 6 oz
Spinner adapter: 1 oz
Extra fuel: 8 oz
Regulating pump / mount: 1 oz
Total: 56 oz.

That's a 5 oz. difference. Granted you may be able to knock off 3 oz or so by using a lighter mount, so let's say there is an 8 oz difference.

I thought about this for a long time and decided that a 5-8 oz difference was acceptable considering the HUGE amount of power I'd be gaining along with the convienience of gas.

I'd love to try both engines and see...maybe I can coax my neighbor to let me borrow his 1.60 before I stick the ZDZ on the Katana...

-Tom

Just for comparison my os160 with a pump and a slimline pitts weighs 39 oz (just measured using digital scale)including thrust washer-bolt etc add ~3 oz for a mount (gp plastic). I think you will find you will need a bigger battery too for the gasser unless you want to recharge every 2 flights, add 2-3 oz to gas. If this plane has to have the nose weight why not , but that is what Im curious about. can it balance with a 160. Im not sure but I doubt an extra 4 ounces of fuel weighs 1/2 pound (16 oz vs 20 oz). I am really not trying to argue but I am a lighter is better guy too

Yep, I'm not arguing...I'm not saying that the ZDZ40RV is the ultimate solution...the OS 1.60 might be better if it can be made to balance.

Some of the weights I posted were taken from specs and not actual measurements...and I figured a 12 oz tank for the ZDZ.

A 10 oz difference between flying weights starts to become a pretty big deal. But if you need to relocate all three servos to the front and STILL add noseweight the ZDZ becomes more attractive. I prefer my elevator servos in the rear and my rudder servo up front on pull-pulls. What about using digital minis for the elevators...could reduce the amount of nose weight (if required) with the OS 1.60.

I will beg my neighbor to let me borrow his OS to see if the plane can be balanced with it. If so, maybe I'll beg him a little more and see how it flies with the OS before mounting up the ZDZ. Who knows...I may not use the ZDZ after all!

Decisions decisions...

-Tom

Hold the presses...in another thread a guy with a GSP Katana said that with an RCS 1.80 the plane weighed 13.5 lbs dry! I may end up using the OS 1.60 after all...

-Tom

I have heard the OS 160FX pulls the Katana around real well, unlimited vertical for sure. I thought of getting one before I bought the Saito 180 for mine, I just couldn't live with the "model airplane sound" it makes.

The OS are far more efficient than the Saito. Not Knocking the Saito (I like and own those too) but the OS is the best running engine I own. 1800 idle and instant throttle response to 8500 on a Mejzlik 18x8. My Creek Extra is a rocket vertical. This combo pulls my friend's World 80" Extra unlimited but slower. The numbers are probably closer to a 15-20 oz difference from the ZDZ also. I have to concede though, the ZDZ is pretty light for a gasser.

well i am going to try this 120 "twin" OS i have... probably wont be a rocket but should sound cool and do ok.. i am not a 3d nut any how. and if it is a real sled. ill yank it and put on a Moki<sp> my buddy has.... (has a 1.8 and a 2.1 i think they were). and go trhough fuel like water...
my kit is moving along.....got 4 servo`s some 4721`s i had brand new in box. need to drum up a couple more...
tail is on..... figuring out what i am going to do with fuel tank.....one that it cmae with is small.. i think under 500cc`s... and when i put a larger one..i need to see where..i dont think way in the nose(like stock unit went) is such a good spot.

and work on mounting this twin up front so it lines up with cowl.. hole(for prop). and. see where this exhaust may go...(has short lil straight pipes.
little by little i am getting there

The tank they supply is about 380cc or like 14 oz. Just a bit small. How efficient is that 160 twin?. If you go Moki, use the 1.8. It will have plenty of power, about the same as the 160 FX, and more fuel efficient than the 2.1. My Moki 1.8 and OS 160 use about the same amount of fuel and a 16 oz tank is fine and what I run on them. My 160 runs better and is 8 oz lighter than the Moki.

its a "120" twin ,,,,,,,,, its a few years old... but brand new in the box is why i want to try to use it.....been looking at it for a while.. its worth a shot...not much harm done if it does not perform. ill just change it out
thanks for info...on moki stuff... i will keep that in mind...i am curious on this twin... as well.....never seen one /heard one go.

Traded for a Creek 72" Katana and put an OS 1.60 w/ pump on it. Flew first time today, very nice, except engine kept dying. The OS is more than enough power and it DOES 3D well. I think I am tail heavy, where is everybody balancing in accordance to the wing tube?