gnirwin

My Feedback: (25)

I bought a new CG Ultimate 10-300 a few weeks ago and I need to decide on an engine for it. I want to go with a four stroke and I am leaning heavily towards the Saito 120 but am wondering will I be upset later if I don't get the 150 for a 30 dollars more. I am concerned with fuel consumption and too much vibration from the larger engine. Does the 150 create alot of vibration like I heard the 180 does. Are these valid concerns? Which size would have more applications or is it about equal between the two? I think both are about the same weight, correct? I guess what I'm really asking is, for the little bit of price difference, why would I buy the 120?

GarySS

My Feedback: (13)

I have heard that the 150 does not vibrate as much as the 180. All 4 strokes have some vibration.
The 120 weighs 29.8 ounces verses the 150's 32.7 oz. R/C Report tested the 120 using a 15x8 prop at 175oz. thrust @ 9.0K RPM. The 150 did a 16x8 at 220 oz. thrust @ 8.5K rpm. Note that this was down in Alabama (lower elevation). These propellers were Zinger wood props. With the larger displacement the 150 will naturally be stronger. Gas mileage probably wouldn't be an issue between these two. Personally I would go with the 150.

William Robison

My Feedback: (3)

[b]Irwin:

My personal opinion is that the FA-120 will work fine with a plain mount, the FA-150 will benefit from a soft mount, the FA-180 MUST have a soft mount.

The fuel consumption at full throttle is in proportion to the engine size, properly adjusted either one will give good flight times on a 16 ounce tank.

Bill.

Flyer95

My Feedback: (1)

Hi,
The vibration level also depends on the airframe size, weight and stability and the firewall. On a 90-sized airframe the saito120 would be sufficient but on a 120-sized airframe the 150-180 would give more power. I have a Saito 180 on a 80" airplane for funfly-aerobatics. The performance is good and the vibration level is very low. I am running 15% nitro. Good luck /Amir

outssider

My Feedback: (23)

the 120-150-180 are virtually identical in weight. 120 and 150 share the same exact case. 180 is slightly taller but can still come in under 32 oz and has the same mounting holes.


I think it is a misconception that the 180 uses more fuel. Fuel usage is more a function of weight of the plane and the speed at which you fly, and drag will play a part also.

I run a 180 saito on a 9.5 lb plane for 13 minutes and use less than 12 oz fuel. engine runs at 1/4 throttle most of the time, but occasionally i need 100% of the power the 180 can put out.

what could I gain by using a 120 ?.... fuel consumption ??....don't think so, because to move the plane with the same authority I would probably need to be at half throttle or more....this would use as much fuel as my 180 at 1/4 throttle.

maybe weight ??? my 180's weight is 31.5 oz with muffler washer and prop nut (modified muffler)


shaking ???.. does the 180 shake my plane apart ??? nope !! ..not that either !! it will shake more than 120 and 150 but that is always going to be the case (bigger engine always going to shake more)...and it is a myth that you need a special mount, any hard mount will work fine...

you really have everything to loose and nothing to gain by using anything less than the 180...

Barnowl

My Feedback: (2)

I have two CG Ultimates, one powered by a Saito 120 and the other by a 150. While the 120 is a good performer, the 150 is an extraordinary one. Vibration is not an issue, nor is fuel consumption. Go with the Saito 150!

3dbob37n

Anytime you get a big piston banging around inside a cylinder you are going to have vibration and shaking. (Note not Shack as in Radio Shack)
I have been using 150's for some years now and they are great performers and think you would be unhappy if you settle for a smaller engine.
I installed an aluminum motor mount on my last plane with a 150 in it and this did seem to quiet the vibration down quite a bit. Obviously, a really rigid motor mount does help.

3dbob

gnirwin

My Feedback: (25)

Thanks for the help. I bought the Saito 150 today. This is the nicest motor I own to date. I can't wait to get the plane assembled to see how the engine runs.

Hobbsy

My Feedback: (102)

It would be best if you familiarize yourself with it on a test stand rather than torture the plane while your Saito learning curve straightens out.