Hi All,

I've been running some Saito .40 four strokes for awhile and find that it is an incredible engine with lots of power. Currently I have one in a Pat Johnston profile Corsair and it works great. This plane has a really thick wing and a lot side area. Does great. Am wondering though how big a plane this engine will really handle, in comparison would it fly something like a Fancher Imitation? Of course the weight would have to be kept manageable, but is this realistic place for this engine. Going up to the next size engine seems like having to go to a larger airplane, like a Saturn size and really didn't want to do that. Any sugggestions would be greatly appreciated.

Thanks much,
Gerald Schamp

My Saito 40 is it baby!! As someone who has been around model airplane engines virtually all of my life, the Saito 40A is without doubt one of the absolute finest pieces of hardware I have ever owned!

Thanks all for your feedback. The Fancher Imitation is about 620 Sq. in. I am pleased with the power this engine has. I have been running SIG Champion fuel, 10% nitro with the 10/10 blend of lube. I have been recently told that I should not be running fuel with any Castor in it as this gum up the valves. I haven't tried running the engine on the new fuel, 20% nitro with all synthetic lube, so I can't compare yet. Was running an 11 X 5 Rev-Up prop, but not quite enough pitch although the plane stayed out on the lines just fine on 62' line eye to eye, lap times were a bit slow at 6.0, really. Could eat a sandwich between manuevers, but while it was kinda fun, more pitch was needed. I am ready to try an APC 11 X 7 and see what that does. The Corsair is a big plane, 600 plus sq. in. and with a huge profile fuse. So the engine will work no doubt about it. Was just trying to find out what the capabilities are.
Thanks,
Gerald Schamp 

I have never run anything less than 6 pitch on any of my Saito's. They are not really designed for that low pitch high RPM business. When you stick the nose of a Saito up, (say, a reverse wingover) they don't fall off like a 2 stroke. They run more like a Toyota Tundra.

Thanks for the picture Willis, that is exactly what I was looking for. I am considering this size plane, only a profile fuse. Actually have the fuse and tail feathers framed up. I am going to use Randy Smith's Vector wing, pretty much all Vector. This is the mid size Vector not the .40 or the SV-11. It should work pretty well, film and rattle can finish, trying to keep it light as posible.
Thanks, oh and by the way, I got some of the TT 11.3 X 6.5 props too, 3 days to get them, wow.
Gerald Schamp 

Thanks Walter, I really appreciate them.

Gerald 

Guys,
I'm looking for a motor for a TF Nobler. Would a Saito 40 be enough. It seems pretty light. How heavy and much wing area is appropriate for the Saito 40??

Thanks

Mike

More than enough,  TF Nobler is smaller and lighter than most of the designs discussed above.  Nobler was designed for Fox35,  some guys fly them with strong .25's.

Guys,
I'm looking for a motor for a TF Nobler. Would a Saito 40 be enough. It seems pretty light. How heavy and much wing area is appropriate for the Saito 40??

Thanks

Mike

I own a Saito 40A weight 45-50 oz. Saito 40A is a 550sq. class engine.

Mike - I have the Brodak Nobler and I have flown it with a number of different engines, including the SAITO 30 and 40.
The 40 was way more than enough power. The flying weight was around 46 ounces and for me, it was a bit too much power.

I think the TF Nobler is a bit larger than the Brodak version so it may be a better match to the 40. Remember, you can always throttle it back a bit.
With the stock length nose, I can almost guarantee that you'll need quite a bit of tail weight.

For what it's worth, I flew the Brodak profile Cardinal and P-40 with the SAITO 40 and it worked extremely well on both.

Bob Z.

Gerald: I used to have a Saito 40 on my Imitation (electric now for
learning purposes) and it had absolutely no problem at all hauling
it around. The Saito 40 is plenty powerful to handle planes with
600+ sq in of wing. The Imitation/Saito 40 is an excellent combo;
go for it.

Later, Steve

Change of plans on the TF Nobler Saito combo.
I put the Saito 40 in a Pathfinder ARF. 55" wing 620" area. 11.3X6.5 TT prop, 20/20 fuel.  Clunk tank with muffler pressure. Spray bar hole opened up to .046" and I removed the venturi insert.

Open venturi RPM ~ 8800. I choked it down to ~8400 rpm. With an APC 11X6 it turns 9300 rpm unchoked..
On 61' lines it turns laps at ~6 sec (TT prop launch at 8300 rpm), 2oz of fuel lasts 4:30 min.

Right now I'm flying straight and level. It's a bit windy and the motor only has ~1 hr so it probably needs some more break-in time and calm winds.

Seems like I should be using more fuel and going slightly faster, but this is a big plane for a 40 4S.

Change of plans on the TF Nobler Saito combo.
I put the Saito 40 in a Pathfinder ARF. 55" wing 620" area. 11.3X6.5 TT prop, 20/20 fuel.  Clunk tank with muffler pressure. Spray bar hole opened up to .046" and I removed the venturi insert.

Open venturi RPM ~ 8800. I choked it down to ~8400 rpm. With an APC 11X6 it turns 9300 rpm unchoked..
On 61' lines it turns laps at ~6 sec (TT prop launch at 8300 rpm), 2oz of fuel lasts 4:30 min.

Right now I'm flying straight and level. It's a bit windy and the motor only has ~1 hr so it probably needs some more break-in time and calm winds.

Seems like I should be using more fuel and going slightly faster, but this is a big plane for a 40 4S.

Sounds like you are in the ballpark, I would shorten the lines a couple feet before messing with the prop or RPM. It might need to turn the TT prop a little faster to overcome the drag of the airframe. I would try for 5.3-5.4 lap times.

Your not out of the ballpark with your fuel consumption, now that I discovered a Sullivan 4 ounce slant only holds 3 1/2 ounces I figure I only use about 3 ounces for 6 minutes.

Oops...my bad.
I timed the Pathfinder today and 5 laps in windy conditions took 27s. Thats about 5.4 sec a lap.
I can only guess that the difference between flying the plane and counting off 1 mississippi...2 mississippi.... vs watching the plane in my lawn chair using a stop watch is another confirmation of Einstein's theory of relativity. Or, the stop watch is more accurate.
Naw! You can't buck the laws of physics.
The Saito 40 was spinning faster on the last couple of flights today than yesterday. I choked off the motor back down to 8500 rpm. Must be the motor breaking in as Lou suggested.
I had an experienced Valley Circle Burner fly the plane and he really liked the consistency of the Saito throught the flight.