Engine Weight vs Performance
 

General Question:

A Saito 100 weighs 20 oz while a YS 91 weighs 26 oz

Will I get better performance from the YS even though I am increasing the overall weight of the plane by 6 oz. ???

I am trying to decide which engine will be a better application for the Ace RC Staudacher (60 size). I think the Saito 100 may be the better choice due to weight. The plane will weigh 7-8lbs full up. I know the YS touts more RPM, but does the RPM increase "outweigh" (no pun intended) the added weight of the YS over the Saito????

Thanks for any input

Engine Weight vs Performance
 

I know this doesnt answer your question but one thing you must consider is how the plane balances. I have a tai ji 60 which I installed a ys 91 into. I still needed 4 oz weight in the nose in order to balance it. with the saito 100 I would have needed 10oz. In this case the ys 91 was the better choice of the 2. From now on I will build my plane and check how much nose weight will be needed. I will order an engine based on what I find.

Engine Weight vs Performance
 

Thanks for the info..... I often will move anything dynamic, batteries, rcvr, etc, to achieve balance. I try hard not to add any static weight to my planes.......

Assuming the only difference is the weight, does the RPM gain really buy me much? I think it might. I have heard that 500rpm is like another 25% power, if this is true, then I should use the YS for sure.

Thanks again

Engine Weight vs Performance
 

getting up toward 8 lb. saito 100 will have a tough time pulling out of hover with much authority.

Engine Weight vs Performance
 

thats the kind of information I am looking for, thanks so much. Great forum.

I fly a sig something extra (40 size) with a Magnum 91 4s (13x8). It flies at 6 lbs and gives me full vertical anything.

Yes, I am from the school of math that clearly defines 90 size 4 strokes fit into 40 size airplanes.

Starting to look like it will be a YS 91 for the 60 size staudacher. My math says 120 size, but not my wallet........Then that darned weight thing again.

Thanks for your help......

Engine Weight vs Performance
 

Prop selection also goes a long way in maximizing your power/weight ratio.

Remember that a staud is a very shortly coupled plane, and arent really designed for 3d work. The staud in general is similar to a giles 202 in its flight envelope. There are several GP Ucando's runnin saito 100's, around 7 1/2- 8 1/2 lbs, and they rocket out of hovers, accellerate vertically, etc. They are also doing it with 16/4 props. That staud isnt going to like to fly that slow.

Do a search on the saito 100, and see all the various pros/cons of the engine, and how many planes they are run in. You might also be able to get away with lower nitro% in the saito. Another thing to consider with the YS is the fuel tank, the pressure system seems to like to split stock tanks on quite a few planes.

Just some other things to consider.

Steve

Engine Weight vs Performance
 

Thanks for the info...... I like the way the plane looks so hopefully I can follow through with flying it. I am rather good at landing on the street with curbs, lightposts and the like, so I hope I can handle the 'staud' when slowed down for the landing. I guess from what you are saying, i really wont get precise aerobatics which for my skill level may be more than adequate. I still have a long way to go to consider myself very proficient at flying.

This could be a good application for flaperons....yes???? My radio is capable (Flash 5). Any suggestions on initial settings (% of this or that) that may be helpful for slowing her up a bit to help me land.

Thanks again

Engine Weight vs Performance
 

You can get very precise aerobatic performance from a staud, just dont expect it to 3d very well right outta the box. We have a guy at our field who does precision aerobatics with an old trainer, and does them very well.

Flaperons will help you with aerobatics at lower speeds. Percentages will vary on your tastes and abilties. Start off low, and move up in small 5% or so increments. Do it a couple of mistakes high. Turn them off when tumbling and snaprolling (which the staud will do quite well), and turn them on for tighter loops, and great spins.

If your radio has an airbrake switch, employ that too. A tip would be to flip your ailerons up, as spoilerons, instead of flaps on final approach. This will help "plant" the plane downward, and reduce the risk of stalling. Flaps will produce excess lift, and bleed off airspeed too quickly, and it will snapstall out (not a good thing on final approach). I did this with great effectiveness on a pattern plane. You wouldnt want to go much higher than 5-10% at first, and do it up high on simulated approaches. Fine tune that switch to your comfortable sink rate. I have no clue how to set up a flash 5, but someone on here should.

Steve

Engine Weight vs Performance
 

also the more weight you hang on the ends the more barbell effect the plane will have.