huck1199

Is a Saito 56 adequate for a .40 sized 72" ws Beaver?

earlwb

4 stroke engines do not behave like 2 stroke engines as to how restrictive the exhaust is.
What I would suggest is running the engine with and without the exhaust and measure the RPMs and see what it really does.

with 2 stroke engines I have seen more restrictive exhaust mufflers causing as much as 2,000 RPM drop in performance sometimes more too. But I haven't tried measuring a 4 stroke engine yet to see what happens.

clytle374

Yeah, 2 strokes won't tolerate back pressure since scavenging isn't positive like a 4 stroke. Not to mention how much easier carb tuning is on a 4 stroke. I'm never going back to 2 strokes, in fact I'm waiting for 4 stroke chainsaws.

I'm kinda tired of working on this plane for now, but sometime I'll take the cowl off and try different setups for comparison.

Thanks
Cory

Hobbsy

My Feedback: (102)

OK Saito friends, I finally finished a home for my Saito .40a I bought from MM37 about 4 years ago. I tried the little .30 but the plane was way tail heavy. Using the .40a, putting the battery under the tank up against the firewall and using Harry Higley's Spinner nut and lock nut it is perfect. It hangs perfectly level at 3.5" behind the leading edge. Hope you like my, I'll know when it upside down scheme. I could use my old FA .40 but it looks kinda big on there.

huck1199

Is that a MKII with aelierons?

Hobbsy

My Feedback: (102)

Yes sir, Thanks. It also has a bolt on wing using a single bolt, very easy to do

PS, if it hadn't had ailerons it would have ended up with them anyway, I'm just that way. The entire plane is glued using SuperPhatic from Hobby-Lobby.

RC Specialties

Cory,

Using the 90 degree adapter should not result in a power loss. However, the header pipe should not be threaded in passed the bottom of the female threads in the adapter. Doing so could create a restriction in flow. I have many customers using this arrangement with no power loss.

Jim

clytle374

I'm sure I screwed them together as far as I could trying to keep from fracturing or striping the thread. I'll check that right now that I understand exactly what you mean, should of foreseen that myself. My concerns are more with the length and number of restrictions than the 90 itself.

Thanks
Cory

RC Specialties

Cory,

This arrangement should not cause any problem. As another poster suggested try it both ways. You should be okay.

Jim

clytle374

I had the manifold screwed all the way in creating a large restriction. Not complaining, but might want to put a note in the package. I wasn't complaining about your product, it's much better and lighter than the Saito 90.

Please don't misunderstand my question. It was merely me wondering if the neat and quite setup was hindering a plane built for power.

Thanks for the easy and free increase in power.
Cory

RC Specialties

Just trying to offer a suggestion. Happy Flying!

Jim

mike early

Love it. Everyone should have a plane with a Saito .40a.

frets24

My Feedback: (15)

Mike,

What RPM's are you getting from that combo? Reason I ask is that I have a used 91 that just got new bearings and a Bowman ring in prep for powering a 72" ws/12lbs warbird and I'm not sure whether or not this is going to be a good choice for this model in the end.

hsukaria

Nice plane!! Wouldn't 12 lbs be a little heavy for a 91?

clytle374

I just tested the engine after fixing the manifold being screwed in too far. I had to do some major retuning. Before for engine peaked at 8400 and backed off to 8100. Now it peaks a touch over 9000 and I backed it off to 8700. I'm guessing 600rpm will be quite noticeable in flight. Isn't a 7% increase in rpm more than 7% in power? Sounds right, but not sure right off hand.

I'm so happy, I'm sending you a Christmas card this year.

Cory

frets24

My Feedback: (15)

Thanks; It's a KI-61 Tony. Started off as an arf but has been stripped down, disassembled, modified and rebuilt....probably would've been a lot easier if done from scratch...if I had access to a canopy it would've been!

Very abreviated build thread begining at post #22 here. http://www.rcuniverse.com/forum/m_80..._1/key_/tm.htm

Don't know...I've never really known of a formula for engine to weight ratio, but it would be nice to know as a jumping off point. The plane was supposed to be 60 2c/90 4c and looked a bit over powered in the advert vid. I'm pulling a 8lbs12oz 62'' wing Me109 with a Saito 62 over proped with a 12x8 3 blade and it does pretty well at 7700RPM....was just kind of using that as a basis.

As always; I'm open to insight, suggestions, experience and commentary The 91 is new to me so I'm not sure as to what to expect from it prop and RPM wise.

Thanks!!

Rudolph Hart

Thanks frets,everytime i see someone flying a warbird that ain;t a spitty or mustang is good,specially with a fourstroke i fly a midget with a 115

mike early

I will tach the .91 with the MA 13x8 3-blade. I have before but have forgotten. You will love it.

frets24

My Feedback: (15)

Thanks, Mike.

lopflyers

My Feedback: (12)

Hey guys I have a question.
I need a new muffler for my 62, 4 stroke, is it 12mm or 13mm?
Where is the best place to find it?
Also I am getting a knocking sound from this engine and I am not sure if it has to do with the broken muffler??

retransit

My Feedback: (18)

It's a 10mm. See RC Specialties:

http://rcspecialties.net/products.php?model=TH10X1A

Nice products.

Bob

earlwb

I had a pilot error today and killed my low wing aerobatic plane. I needed about 6 more inches of ground clearance and it wasn't there. The wing is about 100 feet back behind, and with assorted parts in between is the horizontal stab. The battery is where I stood to take the pic. The poor Saito .80 looks to have turned out OK though as the plane came in flat with the landing gear taking the hard hit. A good washing and oiling and it'll be as good as new again. But no worries, I have been flying the plane since circa 1991, and I still have two more like it in the shed I can put together. It was a "Split S" too close to the ground that didn't work.

w8ye

My Feedback: (16)

Our thoughts are with you on your loss.

clytle374

Ouch, sorry about your loss. At least it had a good life and went out like a plane should. I can't seem to identify the remains, what was it.

Cory

PS the extra 600rpm was a great addition to my Edge today.

earlwb

It was a RB-3 design from the early 1990's. It a ARF design with a 1 piece wing (no gluing the two halves together) and has a a balsa and plywood  built up fuselage with a foam core wing and is painted. There were three different models, the RB-1 was a flat bottom airfoil high wing, the RB-2 was a Symetrical airfoil sport plane, and the RB-3 was a low wing pattern style of plane. They were made in the Philipines at the time and imported by my best friend. But due to manufacturing problems with the painting they never made it to market.