I am considering one of these for a Sig extra and wondered about reliability/performance issues with the engine. Anyone who is running one of the smaller ones, 140-180, would love to hear from you.

Steve,

I have an RCS 140 that I am presently running in a 1/4 scale Laser 200, good performance but not unlimited vertical.

I bought it used from a club member who ran it in a Pitts special that met an early demise when the upper wing departed.

The only problem that I have had was with the ignition module. Other than that it has been bullet proof.

Good luck

Jerry

im useing one on a 60 size U-can-do, it is great and does have unlimited vertical.

Glad to hear the motor is reliable. The Extra 300 XS weighs in at around 13-15 lbs from what I've read, which one do you think I need for this plane? It doesen't need to be "Unlimited" but I would like it to be "authoritive" and pull out of a hover. For that matter I think it should hover


The RCS company is located 30 min. from where I work, so I think service if needed won't be much of an issue.

Steve,

I have not actually weighed my Laser 200, but I expect that it is in the same weight range you are talking about. The 140 will just barely hover that. So the 180 definetly would be a better choice, but I am not sure even that will give you the kind of performance you are looking for. Suggest you talk to RCS about what kind of thrust the 180 will produce. For the kind of performance you are describing thrust needs to be something like 1.5 times the weight.

HTH

Jerry

You are right, sounds like a plan to me.

you will need the 180 since most 120 size planes will weigh around 14lbs. my u-can-do weighs only 10.3 lbs and the engine puts out about 14lbs of thrust, thats what my fish scale said anyway. but i am currently building a Balsa Nova 120 and it will get a 160 or bigger engine,. did anyone read about the new 58cc motor from MVVS at the Morris Hobbies web site ? its said to have 9.6 Hp at only 3.75 lbs, that about what the 1.8 weighs but almost has twice the power.

Well, it's a done deal. I took the Saito 1.50 back to the hobby shop and had them order me the 180 from RCS. 22 lbs of thrust should do the trick. I also got a delivery date on the Extra of next Friday. Now I just need the servo's to get here and I will be a building fool I love the big Saito's but the cost of that 30% heli fuel is killing me. The kicker was last weekend when I went through a gallon of it in one day! I run my 4 strokes just a little on the rich side, mainly because I can't stand the thought of killing one cause it got too lean but 1.1 oz. per minute is just getting too expensive.

I have resisted the urge to go to gass untill now but economics is forcing me to bite the bullet. I still refuse to put a weed whacker motor on a airplane though The RCS is a good looking light engine.

Well, since they are currently back ordered on these engines and have a waiting list, I went with the ZDZ 40. Means a little more work but hey, mo' power too!

The ZDZ 40 is a good match for the Sig Extra, I put one on mine this winter and love it. It was my first gas motor and definetly won't be my last. It's about the only plane I've flown all year as I just don't want to mess with the glow motors.

I would put some tri stock on the landing gear block, and firewall. I had reinforced the firewall but not the landing gear block and last weekend my gear block busted out. I think the more vibration from the gas motor had something to do with it. I did have a less than perfect landing but it should not have been enough to rip the gear out.

which one did you get the Sportsman with reed valves or the one with the rotary valve?

I got the rotary valve engine.

Mark, how bad is the vibration? Is it a major issue? How did yours balance with the ZDZ? What prop are you using & how well does it work for you? Sorry for all the questions but I have been waiting a while to get this plane ready and would hate to see it come apart. I just wish it had a two piece wing.

The vibration is not to bad, just a little more than the Saito 1.50 I had on it the last 2 years. Just shakes some at idle. I'm using a Bambula 20x8 turning 7600 rpm, i've tried a 20x10 bambula but I like the planes speed better with the 8 pitch prop. It was really fast on the 20x10. I've got about 2 oz of lead in the tail to balance. I have a 1200 mah nicad on the ignition, I would go with a smaller pack around 800 mah or so to lose some weight up front. I can fly 3 or 4 10 min flights and my ignition battery will only use about 300-350 mah. Definetly wish it had a 2 piece wing, but mine is about 3 1/2 years old, long before the Patrick or GP Wagstaff came out. If I had to replace it I would get one of them as they are slightly bigger.

Mark

Well Mark, thats good to hear about the vibration. I went with the Sig for two reasons, one cause it's just so dang good lookin' and the main one, it will fit in my jeep cherokee with a little engineering. The better half probably wouldn't think to highly of me if I said I wanted to trade vehicles 'cause my plane wouldn't fit! My excuse for getting it in the first place was the grass at the sod farm I fly at was getting to thick to land in.