Author Topic: Saito 40A (Read 2691 times)

Greg L Bahrman · « **on:** March 08, 2007, 06:11:24 PM »

Hi All,
I have run six 3 minute runs on a old 10 x 5 Top Flight prop. The fuel line from the muffler to the tank was black thru the first 6 runs after that it cleared up and the black is gone away. I switched to an 11 x 7 Zinger Pro and have two 3 minute runs at this point. I have an electric starter from my RC days so I let it charge overnight so it would be all set to go after work for more breakin runs. The venturi screw is blocking off approx. 1/3 of the opening at this time. The gas tank is a Great Planes 4 oz. clunk non-uniflow. I put my finger over the venturi and rotated the prop once. This thing sucks great. No big deal it's just kind of weird, when choking a 2 stroke the piston is going up and when choking a 4 stroke the piston is going down. Attached battery and rotated the 2 inch spinner backwards against compression like I used to do on my RC ships. Not violent, just a casual rotation and the sucker fired off no problem, wow this is exciting. Ran out the 3 minutes and gassed her up again. I didn't want to wait to long because I wanted to see if it would start hot. Finger over the venturi again and one rotation or less. Attached the battery, rotated the spinner backwards again and boom it was running, how easy is that? Picked up the Fromeco Tach and pointed it at the prop. We're running an easy 8800+ rpm, thats with an 11 x 7 Zinger Pro folks and the thing is pulling like a mad race horse. Kinda neat the plane remains pretty clean with the muffler pointed down, I guess I could point it down even more but I like the way it looks now. The weather looks good for this week end so I will be able to get the first flights on it. Makes an old mans heart jump. Will keep you posted on how the flights go........Hey gotta go, it's probably cooled off by now and ready for another run.......I think I hear it calling me.......Later

Hey, I have a question...All my passed 4 strokes had crankcase breathers with a nipple for a piece of fuel line. This engine has a nipple coming out of what looks like the cam area and I have yet to see a drop of oil materialize from it ? is this normal ?

Ralph Wenzel (d) · « **Reply #1 on:** March 08, 2007, 07:49:08 PM »

I have one on a Cardinal (49 oz.) with an 11-6 APC. Lap times (60' lines) are a pretty consistent 4.9 seconds throughout the flight, and that thing pulls so hard my elbow is aching by the time the flight is over. Next time out, I'll try 65' lines.

I keep a cap on the breather when not flying to prevent oil stains in the car, and add some afterrun oil at the start of each session. Tuesday, I forgot to remove the cap, but I couldn't tell any difference in the run.

proparc · « **Reply #2 on:** March 08, 2007, 09:51:22 PM »

I purchased my Saito 40A to try to get an unfair advantage over the competition. I figured that 46\50 size power in a 40 package on .015 lines would give me an edge. If you guys are going to continue to buy these 40A's, there is no point in me competing!!

Greg L Bahrman · « **Reply #3 on:** March 08, 2007, 11:32:33 PM »

Yeah, Proparc I still can't believe it 8800+ with the venturi partially blocked off and a 11 x 7 to boot and the motor is really not broke in yet. Well, we'll see how it acts when it's in the air and I get some more breakin time on the motor. But it looks really promising for this Sat. Supposed to meet Rudy Bustamente at the basin. Needle seems real sensitive to adjustment I think some of that will go away with continued breakin. Regardless it pulls like a freight train for such a little motor. On the ground when it quits there is no warning justs quits. Later

Bill Little · « **Reply #4 on:** March 09, 2007, 07:31:31 AM »

Don't know about the 4S 40s, but if that's the "ugly dog" profile Oriental, then I quit! That thing looks great!

Bill <><

proparc · « **Reply #5 on:** March 09, 2007, 10:39:45 AM »

I will scoot down the Basin to check you out. You better have "got it going on" or else I will tell Robert Storick you suck.

Bob Reeves · « **Reply #6 on:** March 09, 2007, 11:17:06 AM »

Wide open mine will turn an 11-7 at 10 grand, the screw is a necissity

Greg L Bahrman · « **Reply #7 on:** March 09, 2007, 08:04:04 PM »

Quote from: proparc on March 09, 2007, 10:39:45 AM

I will scoot down the Basin to check you out. You better have "got it going on" or else I will tell Robert Storick you suck.

He already knows....SHHHHHhhhhh

Greg L Bahrman · « **Reply #8 on:** March 09, 2007, 08:12:10 PM »

Quote from: Bill Little on March 09, 2007, 07:31:31 AM

Don't know about the 4S 40s, but if that's the "ugly dog" profile Oriental, then I quit! That thing looks great!

Bill <><

Yep, Thats it Bill. A Dog I dunno more like a Turkey I think. Hung in my brothers garage 6 or 7 years that I know of. Finally talked him out of it in a trade for some of my old RC stuff. I put a OS LA 46 on it and flew it once or twice. Hung it up for another year. Now the Saito 40A.....The original paint got melted when the clear was sprayed on so all the edges of the colors are not clean. Kinda has that melted look. Been asked what we were smokin when we painted it more than once.

Greg L Bahrman · « **Reply #9 on:** March 10, 2007, 07:01:51 PM »

Hi ,
Went to the field this morning. Perfect day for flying. Flew the Saito 40A for the first time. Engine seems to be real user friendly. Engine was smooth and consistant. It ran a little richer inverted so I'll have to move the tank a little to even the runs out. Flew some loops inside and outside and inverted. It doesn't sound like it has power but it is deceiving, just give it up and over the top it goes. Hard to get used to it because it's so quiet. I mean I have heard electrics that made more noise than this one did. Second flight was a repeat of the first. Just feeling the thing out, plane is a little sensitive to handle input so maybe I might have to add some nose weight. Although it flew level without any problems, no hunting. One issue I did notice was durning manouvers the inside wing was quicker to respond than the outside. Remember this is an Oriental Profile and the inside wing is 2 inches longer than the outside wing. I think this is causing some trim issues which is why you often see the scab on the outboard wing on a lot of old time and classic planes. The inside flap has more area than the outboard flap. Instead of a scab on the outboard flap to even things out, I think I'll shorten the inside flap at the tip 3 or 4 inches and make it adjustable..........What do you all think?

?.....Oh yeah "Proparc" showed up and helped and said it looked and sounded good from the outside of the circle. Tension was good but I didn't bang any hard corners because of the hingeing I was getting. Launch was at 8200 with the stock Zinger Pro 11 x 7 as was recommended by Bob Reeves and it seemed to work well for my first 2 flights. Engine still needs more run time on it but it still ran good for the first flights and I'm happy with the little 4 stroke. I'll keep working on it. Like I said I plan on flying it in Profile 40 if I can get all the trim issues settled. Fun in the sun. How was your day ?

Bill Little · « **Reply #10 on:** March 11, 2007, 11:43:15 AM »

HI Greg,

With your *hinging*, was the wing "rolling" out on insides, and in on outsides, or was it doing the same thing both ways?

Bill <><

Greg L Bahrman · « **Reply #11 on:** March 11, 2007, 05:38:35 PM »

It was weird...The inside wing was dropping on a sharp outside turn, like starting the outside square diving towards the ground.........Then when inverted and I would dive towards the ground the inside wing would drop.

Bill Little · « **Reply #12 on:** March 11, 2007, 05:56:58 PM »

Quote from: Greg L Bahrman on March 11, 2007, 05:38:35 PM

It was weird...The inside wing was dropping on a sharp outside turn, like starting the outside square diving towards the ground.........Then when inverted and I would dive towards the ground the inside wing would drop.

Hmmmmmmm............
I would trim a 3/32nds to 1/8th inch off the TE of the inboard flap..........

Bob Reeves · « **Reply #13 on:** March 11, 2007, 07:06:25 PM »

Too much tip weight will also do what you are describing, it tries to keep the outboard wing moving in the same direction when the rest of the airplane is turning. You now have allot more engine hanging on the outboard side.. Would bet reducing your tip weight will help.

Bill Little · « **Reply #14 on:** March 11, 2007, 08:21:00 PM »

Doesn't too much tip weight usually manifest itself in *hinging* where the "outboard" wing drops?

But I can see where the top left corner of an outside square would be negatively affected by too much tip weight which could cause the outboard tip to try and continue on in a straight line causing the nose to turn in. Hmmmmmmmmm..............

Bob Reeves · « **Reply #15 on:** March 12, 2007, 06:18:12 AM »

Bet it's dropping the wing on inside corners just not as noticeable. Before I would go cutting on flaps I would try reducing the tip weight and maybe adding a temporary wart to the outboard flap just to see what a larger outboard flap will do.

Was never able to completely eliminate it on my TwistMaster even with a 2 1/2 inch longer outboard flap. However I used a brass tube in the outboard tip to hold tip weight and the brass tube by itself is too much tip weight. It now has equal span flaps and just the brass tube for tip weight. If I don't try to turn a 5 foot corner it will turn pretty flat but if I get on it in a corner it still pops the outboard wing.

One of these days I might try adding a little weight to the inboard wing but with 4 other stunt ships that need flight trim and it being competitive the way it is, it's pretty low on the list.

Walter Hicks · « **Reply #16 on:** March 25, 2007, 10:50:50 PM »

I flew my Brodak P-40 ARF that had a Brodak .40 with the Saito .40A and Ultra Hobbies Venturi with the 10/32
screw to adjust the RPM. Awesome... I did not have any 11/7 props so I used an 11x7.7 Thundertiger gray
prop launch at 7800 RPM. Steady as a rock. Very little wind up and great line tension everywhere I am one happy camper. Also used a thinned Zinger 14x8 on the Saito .72 on my way overweight (84+ Oz ) 740 sq in Laser 200
and it also launched at 7500 RPM perfect run and excellent flight characteristics. Thanks guys , this is the best
that the Saito engines have ever ran. Load the heck out of them!!! And I love the sound or lack of..
It is amazing how the big prop and loading the engines smoothes these guys out. Well Saito .30,40,56,62,72
I have them all and am confident of this set up. Thanks again .

Bill Little · « **Reply #17 on:** March 26, 2007, 07:12:51 AM »

Quote from: Bob Reeves on March 12, 2007, 06:18:12 AM

Bet it's dropping the wing on inside corners just not as noticeable. Before I would go cutting on flaps I would try reducing the tip weight and maybe adding a temporary wart to the outboard flap just to see what a larger outboard flap will do.

Was never able to completely eliminate it on my TwistMaster even with a 2 1/2 inch longer outboard flap. However I used a brass tube in the outboard tip to hold tip weight and the brass tube by itself is too much tip weight. It now has equal span flaps and just the brass tube for tip weight. If I don't try to turn a 5 foot corner it will turn pretty flat but if I get on it in a corner it still pops the outboard wing.

One of these days I might try adding a little weight to the inboard wing but with 4 other stunt ships that need flight trim and it being competitive the way it is, it's pretty low on the list.

HI Bbo,

Don't know exactly what I was thinking since adding a wart to the outboard flap would mimic what I was saying about trimmimg the inboard flap, except it's a lot easier!

On the outside turn when the flap goes "up" coupled with the effects of the bigger prop spinning up front, and an oversized inboard flap deflected "up" the plane will want to turn/roll in on you. As you also say, way too much tip weight could want to cause th eoutbaord tip to keep flyin straight when the "down control is given.

Needless to say, I believe there is something that is too "asymmetrical" in the set-up. I have not had experience with the 4 strokes swinging the bigger props on the smaller planes.

Bill <><

proparc · « **Reply #18 on:** March 26, 2007, 12:35:57 PM »

Well Saito .30,40,56,62,72, I have them all and am confident of this set up.

My 62A coming verrrrry shortly. Right behind you Walter.

Leo Mehl · « **Reply #19 on:** May 11, 2007, 12:12:40 AM »

I have one of these 40's shoehorned into a Nobler. I am still working on the tank to get the run I want. The cowl is thin in a few places but thanks to carbon fibre it's not a problem. The engine has plenty of power but am going to try to get engine to run with clunk tank on muffler preasure. I will soon get it right.

proparc · « **Reply #20 on:** May 12, 2007, 03:19:47 PM »

Quote from: Leo Mehl on May 11, 2007, 12:12:40 AM

I have one of these 40's shoehorned into a Nobler. I am still working on the tank to get the run I want. The cowl is thin in a few places but thanks to carbon fibre it's not a problem. The engine has plenty of power but am going to try to get engine to run with clunk tank on muffler preasure. I will soon get it right.

Why is it that there are some guys who just seem to know how to paint like this and there are cats like me who just suck.

Bill Little · « **Reply #21 on:** May 12, 2007, 07:00:18 PM »

Quote from: proparc on May 12, 2007, 03:19:47 PM

Why is it that there are some guys who just seem to know how to paint like this and there are cats like me who just suck.

Simple, Milton...... for the same reason there are guys like Paul Walker.......

Author Topic: Saito 40A (Read 2691 times)

Walter Hicks