Engine Suggestion

[ratherbflyin]

Hi all,
I am looking for suggestions for an engine choice,
for a Goldberg Ultimate. Two and four stroke options here,
l was thinking along these lines 1- Saito 91 or 100
2- OS 91 FS
3- OS 91 FX
4- ASP 91
5- Supertigre 75 or 90
Also any reasons for an engine pro or con based on your
personal experience would be great. Plane will be 8-9lbs.

Thanks Dave. 8)

[plncrzy]

Based on numerous ones I have flown.... Saito 120. :rock: ... but if I was to pick from your list.... a saito 100 ... this kind of plane requires the power curve of a 4 stroke ...

[ratherbflyin]

Is there really that much power difference between the
Saito 100 & 120 considering the power to weight ratio with
the 120 being considerably heavier? Also by power curve
do you mean torque and the ability to swing a larger prop? :?
Dave

[plncrzy]

Tell you the truth ... I havnt flown a saito 100 ... YET :lol: ... but the saito 120 is sure nice in that plane.... I flew one with a saito 180 also, which was also just awesome but a bit overkill...


MY OPINION ONLY... 4 strokes have a smoother power curve than the 2 strokes (just like motorcycles I guess) ... hence the reason why I prefer 4 strokes in gracefull aerobatic bi-planes and 2 strokes in fast sport planes.

[luv2flyrc]

I used to own one with a Saito 150, that was a perfect combo for me.


Mike

[ronm]

If I were buying a new engine for one of these, I would take a serious look at the YS 110.

Ronm

[David_Moen]

The MVVS 91 is one engine that you may not have thought of. It is a stump-pulling 2 stroke, swinging big props for it's size (up to 15x10!!) and remaining rather quiet while doing it. A very flat power curve makes it excellent for big, effortless aerobatics. Impeccable build quality, a two year warranty and a very reasonable price make it even more attractive!

All that is of course third party opinion! I have one bolted up to the front of my 66" Extra waiting to prove that all this is true!

[lomcevak]

Many years ago, i built a Goldberg Ultimate, with a YS 120 . It was a rocket. Plenty of power, unlimited vertical and very reliable.

[Terry Gauvin]

We have 3 Ultimates flying in Moncton and all fly well. Mine has a OS .91 FX, another has an ASP 108 and the 3rd an ST.90. These all have enough power for IMAC. If you are looking for 3D performance then you will likely need a larger 4 stroke.

[Ian]

If your looking for 3D you'lll have to go bigger then a 90 2 stroke i belive. the one i see fly almost every weekend has an ASP 90 in it and it will not hover, i believe the plane really needs a 120 4 stroke or something in that area, or a 100+ 2 stroke
just my 2 cents

[ratherbflyin]

My intention is aerobatic flying not really 3D with this plane
so l guess then a Saito 100 would be satisfactory :roll:
If the performance is lacking l can always upgrade later.
What do you think?
Thanks for the help everyone. :cheers:

[Terry Gauvin]

If you are not interested in 3D I am sure the Saito 100 will be fine. As would any of the .90 2 strokes.

[plncrzy]

My intention is aerobatic flying not really 3D with this plane
so l guess then a Saito 100 would be satisfactory :roll:
If the performance is lacking l can always upgrade later.
What do you think?
Thanks for the help everyone. :cheers:

And I will buy your saito 100 :checkmark:

[serge]

Hey Richard nice to see you there! I have the YS 120 FZ in my D.P Ulti. Can't wait to maiden it!! Damn winter...

Serge

http://www.wspromotion.com/serge-rc.html

[can773]

I would get the YS 110. First it will outpwer both the Saito 100, and 120. Second since you are dealing with an engine that has a positive pressure fuel system, you can put the tank anywhere like on the CG which is a big advantage in an aerobatics model. The fuel system will also keep your engine running properly no matter what you do with the airplane and what attitude you fly it in.

You will have superior throttle response, more linear throttle, less vibration, more power.....what else do you need?

Sure they are a little more money, but well worth it.

[Ramz-to-tha-Z]

I have to agree with what Terry Gauvin said. I have the CG Ultimate with an ASP 1.08 and it has enough power to hover with very little extra to pull out of a hover. Terry's OS 91 FX runs smoother and has more power than the ASP 1.08 but i also piad much less then he did plus my 108 leaks around the head a bit so i got what i paid for. On a good day it will barely pull out of a hover but on a bad day it will not pull out of a hover. I also have a Great Planes U Can Do 40 with a Saito 100 and I would say that the Saito will outpull the ASP 108 and the Saito also feels lighter. If you don't want to get into any crazy 3D stuff where you don't need alot of power I would suggest any 90 size four stroke or larger, particularly the Saito 100. This type of aircraft is not meant to fly fast but it wants lots of vertical so I would definately go with the four stroke due to its power curve. This plane screams four stroke. If you want to save some cash and go 2 stroke then the OS 91 FX is an excellent choice. If i had the cash I would put the ASP 108 on the shelf and buy a Saito 180 but that's just me. Hope this helps.