Saito 56 Setup Help Wanted

I came back to CL last year after a long absense and was immediately intrigued by the trend toward four-stroke engines. I had tons of experience with these engines from my RC days, but no CL experience. After a brief fling, I shelved the engines until I re-learned how to fly the stunt pattern.

Last week, I finally pulled the Time Machine/Saito 56 out of the basement and fired it up. WOW! It was a very wild ride!

The first flight was on 63 foot lines and the plane almost pulled me out of the circle. The TM weighs 64 ounces, The Saito has a UHP manifold (#3 venturi), OS "F" plug, YS20/20 fuel, and I was running an APC 12-5 prop at 10K ground RPM.

I changed to 65 foot lines for the second flight and was able to hang on, but the plane was still flying 4.7 lap times. I had a Bolly 12.5x4.5 and tried that. The ground launch was 11K and the lap times slowed dramatically (5.5 seconds).

My first reaction to all this excitement is: That Saito 56 sure puts out plenty of power for any model I could ever squeeze into my Trail Blazer.

My second thought is: Was I going the right direction with the Bolly prop? I could sure use some help here. What is the current "Hot Setup" for these engines? I would prefer an OTC solution because I have never gotten any response from Tom Lay about Eather props and Randy hasn't shipped any of the Bollys I requested in my last emails.

I have plenty of APC props and a few Rev Up 12x5s laying around.

I am also considering a change to the smaller venturi. It sounds unnatural to be choking down the power. Everyone else seems to try to boost the power of the 56 and choke down the 72.

Speaking of 72s, I now have two of those and will slip one into my Legacy - after I sign up at the Gold's Gym.

Ron King

Ron: Glad to hear your out getting some flights in. I have been flying the Saito 56 for a couple of years now. I use the UHP manifold, Saito 20/20 fuel, and currently the #3 venturi (though I used the #1 last year). I have been using a Bolly 13 x 6 2 blade prop launching at aobut 9500 - 9600 rpm. This yields 5.2 - 5.4 lap times, and the motor stays very steady throughout the flight. Plenty of time during the maneuvers. I have tried the lower pitch/high rpm setup, but preferred this setup.

Thanks for the help, Steve. Could you also tell me what your line length is? I prefer 5.1, but could probably get used to 5.2 lap times.

I seem to remember your brother and Godzilla trying the higher RPM setups and liking them better. It was a little uncomfortable listening to that Saito scream at 11K, even though I know they use 12K for their horsepower rating. I was afraid if I missed the setting by a hair, I would also have to listen to the engine swallow a valve after a few laps. Most of my time with these engines has been at the 9-10K range, but flying them in RC planes is much easier. You can always throttle back and land if you miss the setup.

Ron King

LAST EDITED ON Jul-05-04 AT 09:31 PM (CDT)
 
Ron,

I'm flying my 56 prowered plane on 67 foot lines. That gives me 70' from the center of the plane to the handle. My plane is about 63oz. I use my own custom manifold. It's about a .310. YS 20/20 fuel with a bit of castor added to bring the oil up to 23%. YS or OS 4 stroke plug (I have a supply of both--they work about the same). I vasilate between a clunk tank and a metal chicken hopper sort of tank. Both work pretty well. The clunker tends to go a bit lean on hot days if I'm not paying attention. I use the metal tank if I need some nose weight. It's about an ounce heavier than the clunker. Ground launch rpm is right on 10,400.

I'm still messing with props a bit. Tried both Eather and Bolly, stock and heavily reworked. The best of that bunch is an Eather 13x5 3 blade, flat back prop (green) cut down to 11.5 inches and re-pitched to about 4. Lots of blade area and a smaller disk.

But the truth is, my current prop, the one that is working really, really well is a modified Zinger 13x5, 2 blade. I got a bunch of them that aren't even close to 5 pitch. Every one in the sack was about 4.25 pitch. I re-worked them to give me a 13x4 with the blades thinned down and the leading and trailing edge sharpened up quite a bit with a slight Phillips entry. I'm easily getting the best performance out of these props. The stock Zinger blades are so thick you can pretty easily re-pitch them down to a 4 from a 5. About 5.2 second laps and good tension pretty much all over.

Ron - contact Willis Swindell. He is running the same combination as you are and has extensive experience with 4S engines. His Time Machine/SAITO .56 does quite well.
Willis in on my 4S mailing list and I will forward any message to him.
Bob Zambelli

Ron,

Keith Sandberg (from Minnesota) has a great flying setup using a Saito .56. He was 2nd in Advanced at the SIG event. Mike Pratt flew his plane and seemed impressed by it.

I cannot find an email address for Keith. Perhaps someone else on this forum get give you contact information.

Fred

Ron: I am using 66' foot lines, making my total length about 69'. My palne has a 63" wing span and weighs 58 oz. It does have a very large, round fuselage (6") so this may necessitate my use of the 13 x 6 prop. I have tried smaller diameter and lower pitch props, but they didn't perform near as well.

Ron,

Don't try to run it like a two stroke. The needle isn't for adjusting engine speed. It is mixture only. I always run mine 1/4 turn rich from peak. Power output is determined by the throttle opening, just like your car, except that the throttle position is fixed. It is the venturi size. Lap times are determined by propeller pitch, not needle valve. Try a 14-4" Desired launch RPM is 9000 to 9500. More scares me regarding reliability and life.

Good luck,