Hello all,

Building a CG ultimate and am considering engines. Hoping for unlimited vertical without compromising the maneuverability from excess weight. Considering the Saito or OS 120. Would the Saito 150 be too much engine?? (If there is such a thing?) Thanx in advance to all the masters!!

Have one with a Saito 120, it screams.
I dont think you need anymore power than that.
Balances perfect.


Ethal86

I mounted two elevator servos in the tail and put a Saito 180 in mine. The only problem I had was had to use a three blade prop and put some fuel tubing on the axles to keep it from rolling at idle. Would torque roll easily (like anytime you shot the power to it). It was fun though.

Mine has a YS .91FS Air Chamber. Power of some 1.20s and 1/2lb lighter. I swing a 16X6 with 20/20 fuel and have gobs of power. I didn't even try to build light and can only imagine if I had! If I did another one, I'd carve a lot of ply out and use lighter servos. You can stuff a huge engine in if you want, but the wing loading goes way up and it doesn't have the 3-D abilities if it were lighter.
My 2cents

I waffled between the Saito 120 and the YS91. I went with the Saito. It seems to be just fine for balance with some careful planning. I'm probably sacrificing 1/2 pound to the YS. On thing for sure though, the 120 is a tighter fit in the cowling.

I personally see no reason to go bigger than 120. Even though there will be no difference in weight, the motors cost more, shake more, and have a greater potential of damaging the airframe when the throttle is abused.

I have a YS 91 on my bipe and it is great...My bipe is wayyy to heavy also (my fault)...but the 91 does a very good job...I am going to put a YS 120 on there only because I have another use for the 91...If you built your plane light I would think the 91 would be a super set-up!!...not sure it would capable of hovering or not...I would say great vertical but it would eventually fall off I think...if mine were lighter I could tell you for sure...dang it...

mine has OS 120, it's a beast......

All excellent ideas and responses.

Thanx all!!!

Mine hovers great! I was originally going to put a YS1.20 in but when I was building the plane I saw Mike Cross flying his on the .91. After a couple harriers to a tail touch and back up again, I was sold! His was still a bit lighter than mine ended up but I can still knife edge loop and such.
The 1.20 would be a guaranteed vertical set up, the .91 is if you keep it light.

Everyone here is talking about the weight of their Ultimates but not giving the actual weight which would be helpful. Just finished my second Ultimate with a OS 120 and it came out 9lbs on the head. Frist one, about 5 years ago, was just under 10lbs. Going to try a 16/6 instead of a 15/8. Anyone tried this?

Mine is 8.25lbs. And, I use to use a 15X6 but it was too fast vs thrust. Switched to a 16X6 and am a happier camper.

Just a suggestion from someone on the outside looking in, but that YS 110 looks about perfect...

I am finishing up my 5th GB ultimate. Between my father and my son and myself I stay busy. Two had YS 120's and two had Saito 120's. The saito combo was the best all round but the YS could easily rocket around. Didn't try 16" props on the ys. This one has a saito 150 (because I had one and the mounting dimensions are the same). Will write back after the first flights. Bare bones with motor, tank and radio is about 71/2 pds.

Jim B.

P. S. Anybody try a yellow aircraft 120 arf with an os 160 in it?

Saito 120, 8.75 lb all-up weight. Unlimited vertical.

"Ilikeplanes" What prop and nitro % are you using with you Saito 120 to get unlimited vertical?

10% Cool Power, 15-7 APC, still very rich, only four tanks through. I'm also only about 500 ft above sea level.

I can 't imagine that you wouldn't have unlimited vertical with a Saito 120 unless your airplane weighs 10 pounds or unless your density altitude is very unfavorable.

I'm surprised no one has mentioned the OS 1.08 FSR. I've been using one for over a year in my CG Ultimate and I would rate this motor one of the best I've ever owned. It's a really good match for this plane. Unlimited vertical, (in fact, you can do vertical snaps and it keeps going) outstanding reliability, easy to operate. The plane weighs 8.6 lbs and I'm using an APC 15x6 prop, running Power Master 15%.

Hey Deadstk,

the guy that talked you into that engine must have been a genius!

Scott

This is my favorite aerobat. I have had others, but once you fly one, YOUR HOOKED. I have managed to kill (4) of them over the past 10 years. My engine of choice is the YS 120SF. Just like a John Deere!! It runs and runs, and nothing runs like a Deere!!
That is my 2 cents. I now have (2) Ultimates the Goldberg with the YS 1.20SF and Ohio R/C with a Q-75XL. Both are a Blast to fly!
All I can say is you are in for a lot of fun whichever way you go. But straight up will probably be the most fun!!!

i am glad I read this. I have an ultimate that used to have a Supertigre 91....what a piece that engine is..anyway I have a 1.80 saito to put on it. I was scared to use it but i think i will now. I was going to sheet the elevator halves and try something different with the elevator servos, maybe change the wire mount for the top wing.....any suggestions? and any weight problems with a 1.80...i think its lighter than the 1.20

The CGM Ultimate taught me huge amounts about 3D and demonstration flying with a YS120NC up front. Unfortunately, it took putting the battery in the tail plus about 50grams of weight back there to balance her out nicely.

Now, the YS110 turns about the same of what the NC turns at about 5 ounces lighter. I cannot think of a better combination for this airplane. Cheaper, yes. Better, no.

Mark

I'm on to the YS 110+Ultimate.. defiantly the best combination!!!

I have the YS 120 FZ in mine, 17x8 APC, weight is 9.75 lb. Radio gear is under the pilot to balance, plus rudder servo under stab.

If building again, I'd go for the new YS110, and look to save weight elsewhere. (like not use those Dubro brick engine mounts and such a large receiver battery).

Hmmm, if I carry on like this I'll talk myself into getting a new one...

seanburg,

I changed my wire mount on the top wing to bolts on the CG Ultimate.

On the bottom of the wing I did some surgery and placed basswood blocks in the same location as the bolts holding the metal bracket that the wire slides through on top the cabanes. The blocks are curved on both sides to fit the airfoil and fill the area top to bottom to prevent smashing the wing when tightening. The blocks are about 1" wide x 1-1/2" long.
After resheeting the area, I made two small "wedge" pieces that conform to the wing and cabanes and did away with the metal piece that holds the wire mount. With 4x40 bolts and dime sized washers (made from ply and covered to match) the bolts go through the top of the wing and bolt onto each cabane with washers and nuts. Its a little more of a pain to assemble it but its been working well for the last 6 months.

I'm with deadstk. If you haven't purchased an engine yet, the OS1.08 is probably one of the best engines you can put on this plane and a much better deal (price for what you get) than any of the other engines mentioned. The 1.08 will allow you to do anything you want with the plane, is not to heavy and requires no extraordinary changes to the plane.