I will start assembling my Swallow EX this weekend and I have to decide what engine to use. I was plannign to buy a new YS91FZ from Central Hobbies (don't want to pay the overpriced 110). The 120 is no longer available, and the price for 140 sport is really good (about $450). I read the review in RCM&E and the reviewer said the YS91 they used was "just adequate" and that it would benefit from a 120. Is the 140 Sport too much for this plane?
Better yet, anybody has a good condition 120NC or FZ for sale?

Well define too much... Many have flown successfully with the extra weight of a conventional 120 and you could argue that you can't have too much power. However, I would say it is a bit ott for the Swallow.

The YS 91 really would be ok on 20% nitro, more than enough on 30% and the 110 shouldn't be more than a few bucks more than the 91. If you can wait until June then it is the one to go for, if not get the 91, it will fly much better with the lower weight over the 140 and you really won't be lacking power.

Probuild in the uk, hwve the YS 110 for £5 more than the 91, so I don't think it should be alot more expensive on your side of the globe.

I have a Swallow EX with irvine 72, I would say that the power on that plain is "just adequate." The AUW is around 3.4kgs. A 140 would definitely be too much, a 110 might be a good choice. I'd go for the 91FZ, or maybe the 110 if I were you.

If you want to consider an alternative to a YS engine, try a Saito 100 [and it's a lot lighter].
I'm using a new 100 with a Swallow EX and, now that the engine's run in, it's a pleasure to fly. This is one smooth model! Enjoy!

Why not go for a 2 stroke? The OS 91FX ia quite a power horse and you will save weight. Use an all round pipe to stop any peakyness and I would say you are there. I say this as I have now seen an OS go up against a YS91FZ on a pattern model. Needless to say the OS was quite a sight, if a tad "unfashionable".

Where is the beauty of a 91FX though, ITS NOT EVEN PUMPED.....
JKO

Well cut me in half and say YS through the middle, but I was very impressed. Swung the same prop as the YS110 too. Makes you think.

I just a called Central Hobbies. The YS 91 FZ is out of stock and they don't expect the 1.10 until mid summer. Their prices are considerably lower than Pro-Build ($275 vs 260 Pounds!). I am thorn between the 4-stroke and the 2-stroke approach. I don't want to cut the nice cowl to accomodate a side mounted two stroke. Í don't know where to get a wrap-around header and a round pipe to use with a upsidedown engine, but I have an Iron Bay fuel regulator to "pump" the OS 91 FX if needed.

What you need is a 'swan neck' header these are readily available. You could use a mini-pipe or a remote muffler as a peaky pipe is not needed here.

$275???? Wow. thats cheap.......

120 nc extremely low time will sell for $200 ship

Very interested. Send pictures please.

I flew a friend's swallow in pattern contest last weekend with an old ys 120. The plane flew great and the 120 was enough power but not really overpowered. I don't see why the ys 140 sport wouldn't work out in this plane. especially if you like to have more than enough power in a plane and know how to used the throttle stick.

HI,

I've engined my Swallow with both an OS 91Fx and a YS FX110. No question in my mind, the YS is the one for this plane. Even using an OS1.60 header, pipe and perry pump, the OS didn't pull in the vertical's like the YS, and doesn't fit the plane very well (Eg. the cover over the header won't fit.

The 110 is just a joy in this plane.

Steve

You are right. The 110 (if you can get one) is ideal for this plane, lots of power and most importantly, low weight compared to the 120 size engines. The plane will fly ok with the 140 sport, but it really doesn't need the power and the extra weight means it won't ever fly as well as with the smaller size engines.

My Swallow is on a Supertigre 91, and it'll go out of sight on a 14x10.

Keep the plane light and you'll luuurve it on an FX

I finally put an OS 91 FX on my Swallow. After struggling with the engine for a couple of flights I finally sorted it out. I was using an Ironbay fuel regulator running from muffler pressure. It seems that the pressure was not enough and the engine died when pulling the nose up. I didn't want to drill and tap the backplate. I will try an OS 140 FI style pressure nipple. I think the OS Surpass 52 fuel inlet with feet (3.5mm thread size). Anyhow, I removed the fuel regulator and checkvalve and the engine runs smoothly . Iam still running it (only 3/4 of a gallon through it so far). I am using an APC 13x8 propeller and the regular muffler and it has enough power for long verticals and big loops. It doesn't have the power for prolongues vertical figures (i.e. vertical eight with rolls, figure M with rolls, etc.) I will try a tuned pipe later (together with the crankcase pressure?).
The only problem I found with the plane is the landing gear. The plane bounced in every single landing (5 so far). It ended in the grass last night and the right leg broke down. The fuselage took the beating with no problem. I am considering retracts or an aftermarket landing gear right now. I haven't weighted the plane but it is built stock with the lightweight OS 91 FX, two Futaba S9101 in the ailerons, two hitec digitals 5625 for rudder and elevator and a micro hitec 81 for the throttle.
Rudder looks impressive in size, but it takes some effort (and throttle up) to rotate the plane through a stall turn. The plane tends to fall from the sky if it slows down too much in vertical.

do you know how much the plane is suposed to weigh? i'm just finishing a quest 90 with a 91 FX and a perry pump and a macs pipe i will come in at around 8 pounds..............from what i've been told it should have unlimitade vertical with stock setup. so i think it will have plenty of power with the pipe. i am going to fly it on thurs. and break in and tune of wed. so i will let you know how it flys..........i'm going to a contest this weekend with it also.

I would guess around 9 pounds. Plane is not featherweight by any means. The built-up wing is significantly heavier than the foam wing I had in my Diamant 90 although they are similar in area and size. I think the aluminum wing tube joiner and the retract hardware built in (wooden blocks, maybe plywood ribs) add some weight to the plane. The original landing gear is also on the heavier side.

What pipe and header are you using with your setup? Did you need to mount the engine on its side?

yes i mounted the engine on a 45*...........it will stick out a little but not too much.........here are the links to pipe and header.http://www2.towerhobbies.com/cgi-bin...?&I=LXZ563&P=M