mike early

Horizon is sending me a replacement on the flex pipe. They are back-ordered until June.

Everyone uses the flex pipe on this plane, it seems. It worked great while it lasted. I realize now what the black stuff inside the cowl was. The flex pipe was leaking. I imagine that decreased performance.

The fuel tank had a problem. The cap-plug was loose. I have changed it to a different one. I am presuming I had no pressure on the tank. How much would that, coupled with an exhaust leak, affect performance?

Hobbsy

My Feedback: (102)

Mike, is there enough room for a TurboHeader?

mike early

No...I have only 3/4" from threads to cowl. I even had to grind down the 90ΒΊ fitting to get it working.

Shack

In an earlier post I said w/a flex pipe you need to anchor it near the end to keep it from vibrating [metal fatigue]. Put some kind of heatproof rubber around it & use an adel clamp [Lowe's has them.] I have seen two break when not anchored.
Shack

Hobbsy

My Feedback: (102)

Mike, this is the difference between the Horizon 90 and the RCSpecialties 90, the RCS being the compact one, I am not trying to be a salesman and I'm net even sure Jim makes the 13mm 90 yet. This is the 14mm one.

RC Specialties

Hobbsy & Mike,

I do offer 10, 11, 12, 13, and 14mm size adapters.

Jim

Hobbsy

My Feedback: (102)

Excellent, I wasn't sure of the 13, Thanks Jim

blw

My Feedback: (3)

Mike- are you getting a lot of visible smoke in your exhaust when you run the engine? Those are low numbers. The first thing I would look at would be for rich settings, especially on the low end.

Hobbsy

My Feedback: (102)

Mike, I tried to come up with some comparable props for my 1.25 to get some numbers, I don't have very many APCs as I don't fly them.
Saito 1.25/stock exhaust
WildCat 15% fuel with 18% 80/20 blend
Fox Miracle plug

MasterAirscrew Classic 16x6===9,450 rpm
MasterAirscrew K 15x8======8,975
Graupner 15x8===========8,795

And, just for kicks
Enya 1.20 GP
WildCat 5% fuel with 16% lube and 3 oz of castor added
Enya #3 plug
Graupner 15x8======9,050 rpm, not too shabby for 5% nitro.

jdr43

"I tried to come up with some comparable props for my 1.25 to get some numbers, I don't have very many APCs as i don't fly them. "


Hobbsy, just curious why don't you use APC Props ?

Jim R

mike early

I also have the MasterAirscrew K 15x8. My #'s for that prop are in the low 8000's. I tried the stock exhaust without the 90ΒΊ elbow, thinking the elbow was a restriction affecting my performance. Not the case. The #'s were about the same with elbow as without. Flex pipe has been welded and repaired, while I wait for the backordered replacement.

I've set the low end where it will transition between idle and WOT without dying. One click either way has an effect. The high end I've experimented with. I can get lots of smoke or barely any smoke. I can slowly lean it until the RPMS drop and then go back to max and then a couple hundred RPM lower.

I'd gladly sacrifice the low end reliability for increased power. It's not like I ever go back to idle when flying anyways. Does the low end setting affect WOT at all?

I have a perry pump that I've never used. It's the pump that runs off crankcase pressure. I'd have to "T" the crankcase but that's no problem.

Any suggestions?

Hobbsy

My Feedback: (102)

The LS needle will effect the performance if too lean, it will render the HS ineffective but that's not the case if you can reduce the rpm by richening the HS needle.

mike early

the 16x6 number of 7700 or so is the Evolution 16x6 prop. I have the APC prop of the same size, but have yet to grind out my spinner for it to fit.

The zinger 15x6-10 prop was 8100 or so.

The MAS 14x7x3 is 8400

mike early

Well, actually the top end needle is rather mushy in it's effect. I patiently wait for the effects before turning it further, but usually nothing happens.


Even if the transition is perfect, the LS might be too lean?

Hobbsy

My Feedback: (102)

Mike, those Zinger props with the 6-10 designation are hard turning props, I can put a Graupner 12x8 on my Fox .74 and get 11,200 rpm but put the 12x6-10 and only about 10,300.

mike early

Surprising, but informative.

I might have had a hole in one of my tank hoses. It seems that one of the lines were pinched at the end of the metal tube. How much affect would zero tank pressure have on performance? I presume it cuts down fuel flow...but I was still able to richen the HS until I had lots of smoke...

Blazer1

My Feedback: (1)

I am new to Saito's as well as 4 strokes and wanted to post some numbers to get your thoughts. I have a Saito 100 on a Pulse XT 60 turning a 14x8 APC 9750rpm on the ground burning 20%/20% Wildcat fuel. The engine has about 1/2 gallon of fuel through it so it is fairly new. What do you think about the rpm? Is it close to right? Will this fuel be alright?

w8ye

My Feedback: (16)

That rpm looks pretty good to me

blw

My Feedback: (3)

I was getting somewhere around 9500 RPM on my 1.25 with an APC 15x6 on the first gallon of fuel. I haven't tached it in a long time.

mike early

I ran two 16oz tanks through it today, tinkering. MAS K 15x8 8250RPM is about the average. I hit 8450 once. I have re-checked the valves. I have decided the exhaust is not a big enough factor to be concerned with (flex vs muffler, etc.). The Air Filter does not make noticeable difference, either. The last tank was the end of the 2nd gallon.
I started back at factory settings and experimented. Transition was never a problem. It always shot to max RPM immediately. It idles below 1900 for quite a while and never misses a beat. I ended up having the low end about 2 turns in from flush. I start 5 turns out on HS and it ends up about 2 turns in from there.
I get more smoke in the mid throttle area than WOT. During transition is the most smoke. WOT is not much smoke at all. I am happy how easy it is to start and how rock-solid it runs

It flies pretty nicely at this power level, but I think I am entitled to more power. Maybe I should get the 15x6, but I am doubting that will give me 1250 more RPM. Or might it?

RC Specialties

Mike,

The 15x6 could very well give you another 1000 rpm. I run an APC 15x6 on mine and it tunes out to about 9250.

Jim

mike early

Using the free prop/power calculators, I would be certain this engine is supposed to produce at least 1000 more RPM with a 15x8. I am sad.

mike early

My flex pipe is supported at both ends, but still vibrates in the middle. Maybe I should try to support it in the middle?

Hobbsy

My Feedback: (102)

Mike, please don't confuse the props with the 6-10 designation with 8 inch pitch prop, they are more like 10 inch pitch props than 8 inch pitch. The only place I've found the 6-10 type props to do a good job is on Diesels. The Diesels thrive on a heavy load and of course idle very slow so you can land with the steep pitch.

mike early

I've cut my spinner out to accomodate my APC 16x6. We'll see how she flies with it tomorrow