Rudolph Hart

Thanks for the answer mike and yes if the south african bowler is fit we're in trouble!

I think the plugs being drowned as the 65" decaf is designed for an upright or side mount and the saito carb is to low..did you say it's dry or wet in dubbo?

NM2K

My Feedback: (14)

"I also leaned the high needle i.e. dropped the rpm about 300-400 from peak where I used to drop it 500."



Most likely this is a typo, but if true, it would sure explain the overheating. You're supposed to richen the mixture 300-400 rpm of peak, not lean it.


Ed Cregger

Giln

Hi Ed,
Yes it's a typo - sorry. I turn the needle out (anti-clockwise) a few clicks to drop the RPM.

Frankly, until this overheating discussion came up, I did not pay much attention to the engine temperature.
It is coincidence that this came up just after I leaned the low needle.
I know I've never been able to hold the engine after a few minutes running.
I've now ordered an infrared temperature gauge from EBay. Expect it this week.
I'd like to know what the acceptable temperature range is. Would it be different at sea level (thats where I live)?

I'll measure a 2 st and my 82 and post results. If we can fly on the weekend, I'll measure whatever is at the field.
There are a couple of 125s, a YS 140 and OS 120 in 4st. The rest are 2st and the odd 50cc.
We've had high wind, rain and more wind the last two weekends - no good for flying. Hope summer arrives before Christmas.

Regards
Gil

NM2K

My Feedback: (14)

I refuse to buy into checking the temps of my engines with an IR gauge. I've been running them for fifty years without a gauge and haven't burned one up yet. That includes engines mounted in helicopters, airboats and aircars.

Four-stroke glow model engines do run hotter than two-stroke glow engines. You shouldn't be able to grab the cylinder head and comfortably hold it immediately after a run. At least you wouldn't with any of mine.

I've had no failure problems with any of my four-strokes, except once I failed to take into consideration the spring loading action of a crappy sawhorse mounted engine. When I went to adjust the low speed needle, the sawhorse was relieved of tension because the barrel (carb) moved to closed when I turned the low speed needle screw. Suddenly, the spinning propeller and my hand were trying to occupy the same space at the same time. I knew I was in trouble when blood and meat splattered up onto my right eyeglass lens and blinded me. Don't do this kind of fiddling when taking powerful pain killers. You'll do stupid things like I did if you do.

Have fun with your IR temp gun. But don't let it get to you. It shouldn't take you long to figure out that its usefulness is very limited.


Ed Cregger

Giln

OUCH!

Thanks Ed. I'll probably end up pointing it at things in the kitchen and the garden before mothballing it then.

Regards
Gil.

Rudolph Hart

I did that to giln and was none the wiser as ed says.If you are keen your 82 should read around 120 to 140C at the spark plug and valve train areas and around 220C at the exhaust.

RC Specialties

Giln,

I have checked a Saito 100 during my muffler testing. I used an infrared gauge as well. This was with the stock muffler. Here are the readings. Compare against your results and let us know.

OAT 92 dgrees

Idle setting 2500 rpm - 176 degrees F at header near exhaust port
Full throttle - 255 degrees F at header near exhaust port
Cylinder head temp - 195 degrees F

Jim

Hobbsy

My Feedback: (102)

Ken, I've also been a WildCat user since 1992 and have never had a rusty bearing, but I use Corrosion X as an ARO. My old .80 has a little rust on the flywheel but I've had it since two years before I started using the WC or the Corrosion X. the WildCat. I use the Premium Extra in the Saitos, OS, and Enya and Premium in Laser and RCV.

sodbuster 1

Ok, just finished the BH Models Spitfire and have a final weight of 10 lbs on the nose.
Installed a 1.15 in it.
The plane has a wingspan of 74".
Will this be enough engine to fly this plane with authority?
Am starting to have my doubts...........

Hobbsy have you run your 1.15 in anything yet?

Hobbsy

My Feedback: (102)

I have run it, I am going to run it some more, maybe tomorrow, I have not flown it yet though.

w8ye

My Feedback: (16)

It is not going to be as warm tomorrow

Rudolph Hart

If it helps sod relax.My guess is you will have ample scale power with a bit in reserve.Spitfires that tip stall are slippery little buggers

blw

My Feedback: (3)

It's the elliptical wing tips that get you when your airspeed is low.

PearHead

Good day All!
Does anyone happen to know what size screw I would buy if I wanted to plug the muffler pressure tap?
Thanks!
ph

NM2K

My Feedback: (14)

-


I would love to see the proof of concept research data behind the elliptical wingtip shape of the Spitfire and the Republic P-47 Thunderbolt.


Ed Cregger

Garthwood

Curious why you want to plug the muffler pressure tap. What's the advantage of doing that ?. Just a question, I'm always ready to know something new. I'm a Saito user, and visits this thread once in a while.

I'm putting together a Hangar 9 Corsair .60, adding to it functional flaps. I have the Saito FA 100 for it as this war bird was designed around it. I am going to use a Graupner 14X7 3 blade prop and a Tru Turn Hub, and a double jam nut. I want to fly this like scale, I don't intend to tear a hole in the sky with speed, the true full scale Corsair was'nt/is not a speeding aircraft. MA makes a 14X7 3 blade prop as well.
Any of you guys know if this prop is suitable for this engine ?. Will it load up the Saito, what RPMS should I expect from this 3 blade prop. First timer to use a three blade prop.
Your comments are welcome. Thanks.

Saito member but forgot my number. Some where in this thread there's a page where it shows the member's #. Too many pages to go thru.

Garthwood

I strictly use Saito engines. From day one I been using Power Master 15/20 Heli synthetic, I use after run 50/50 air tool oil and Mystery M.
I do this after I'm finished for the day. Some guys laugh at this, but I'm the only one that have no problems with rusting bearings and other kind of problems. When the flying season is over, I remove the engines from their mounts and remove the back plate to check the condition of the bearings. I then give these engines one last storage lubrication with ATF or Air tool, drain the oil out close the back plate and put a few drops of ATF or Air tool oil through the heads, glow plug, back barb. Give the prop a few manual spins. Instead of leaving a good glow plug in I exchange it with another one that I don't like to use. When the flying season starts, I'll install a new glow plug. Works for me. I'm not a Saito expert so I have to take these precautions. These jewels require very simple maintenance.
I don't have years of flying experience (6rs.), so I'm not an expert in 4 strokes.

Saito FA120 (1)
Saito FA100 (2)
Saito 91S (1)
Saito FA72 (2)
Best sound I've experienced.

RC Specialties

Garthwood,

I have the same plane and engine combo. I used the MA 14x7 3 blade and it performed well. Flight rpm's in the low to mid 9's depending on fuel. It is a very sweet flyer. One of my favorites.

Jim

pmillerusa

Ok, let me jump in here... Just bought my first Saito today!!

FA91S.. paid $265.00 for it at the LHS.

Looking for a good mount and then will be breaking it in over the weekend. It will be going into a 1/7th Top Flight P-51...

So am I in the club?? :-)

Rudolph Hart

Ed if i read your post right you are wondering how that wing shape can be beneficial??

Having all the cannon or machine guns grouped close in to the prop arc(wing width)is one or were you looking at aerodynamics and manufacturing costs?

NM2K

My Feedback: (14)

-


I was wondering what kind of aerodynamic advantage was thought to be derived from such a shape.

The Spitfire was an interceptor with an emphasis on gaining altitude quickly and maneuverability once at altitude. I would think that load carrying capacity was deemphasized (no attack/fighter function) for climb to altitude performance. This is why I was puzzled when the P-47 used the elliptical form of wingtip.

Later on the P-47 was relegated to mostly attack/fighter type missions and less direct plane to plane dogfighting. With eight fifty caliber machine guns instead of the normal six for a fighter, it was a devastating attack aircraft.

I would have thought that a laminar flow airfoil with butched (squared) tips would have been a better selection of airfoil/wingtip combo for an attack/fighter, such as the P-47. Perhaps it was being viewed as a long range fighter initially and then relegated to attack/fighter usage later on, after the P-51 came on the scene.

It's early and no coffee yet. I hope that made sense.


Ed Cregger

mike early

The MA 14x7x3 prop will turn quite a few RPM more than the 14x7x3 Graupner. Am not sure the Graupner will allow the Saito 100 to get into it's 'sweet' spot.

VF84sluggo

My Feedback: (55)

It has been a looong time, but I vaguely remember my Aero 201 professor talking about the eliptical wing of the Spitfire being an almost ideal wing planform. The lift distribution smoothly tapers from root to tip, especially as the lift coefficient is increased. The eliptical shape also minimizes drag from losses at the tip (wingtip vortex). So, an aerodynamicist loves it.

But, the engineers and structure guys hate it. It is a difficult wing to manufacture. Each wing rib is unique. Spars are a challenge due to the ever-changing planform, making it difficult to build in torsional stiffness. This inevitably led to heavier structure.

So, that's my recollection from Aero class is 1976.

RC

Capt Lou

I have been using the Dave Brown composite mounts on all my Saito installation, principally FA-91 and 100's.

pmillerusa

Thanks Capt Lou... I was looking for more of an isolation mount to protect the airframe. Coming from a 2-stroke background, all the reading I am doing says 4-strokes need better isolation...??? In your experience it looks like that isnt the case.

I need a larger mount for my test bench for this, so I'll be getting a simple mount for that now and then looking more into the rubber mounted ones for the p-51.

thanks