w8ye

My Feedback: (16)

Some people say you can run a 15-8 but Mine seem overloaded with a 14-10.

They are happy with a 14-8.

Don't remember what rpm they turn. I just remember they are happy. Been a couple weeks since I ran one of mine.

daniel9314

Looks like I need to just try a couple different props myself and see what works best.

I'm new to these Saito's, and 4 strokes in general, but already hooked.

Thanks for the help, this forum is a great resource.

w8ye

My Feedback: (16)

A MAS 15-6 will do a pretty loud buzz on a 100. Great on a war bird. The buzz is loudest just as the plane passes in front of you.

stallwart

Since we are talking prop sizes, what thoughts does anyone have for a FA82a on a 5-6lb plane? I've been running a 12x8 from first break-in run.

w8ye

My Feedback: (16)

A 12-8 should be a good choice for a war bird. Should give you a little speed.

Would hurt to try some different brands?

See which one you like best.

People vary in their taste for props. What works for one guy may be different from what his friend likes?

stallwart

I've tried both the MA and APC 12x8s. The MA pulls great, allowing non scale, almost vertical takeoff, and the APC provides plenty of speed, with sufficient pull for takeoff.
Since I am also new to 4 strokes, any input is greatly appreciated.
BTW, the OS "F" plug has worked wonders.

NM2K

My Feedback: (14)

"BTW, the OS "F" plug has worked wonders."



----------------



They always do. <G>

Hobbsy

My Feedback: (102)

So far, my experience is that the OS-f changes nothing when you use it, if it did I'd be raving about it too.

WMB

My Feedback: (1)

I'm getting more time on the 45 now and it runs real nice, idle really coming down. It starts real easy with a good wet prime, rotate prop clock wise till it bumps against compression, five clicks throttle, install glow starter, back flip against compression and it's running. That worked when it was warmer. Last time I flew was 48 degrees and humid with wind out of the north. With the colder weather, it wouldn't hand start, but fired right up with the electric starter. Got it tuned and after it cooled, still couldn't hand start it. Not a real problem, but curious if this is normal? I have the same routine for a Magnum 15 and it also needs the starter when it gets cold.
Speaking of cold, woke up to snow and still snowing but letting up. No wind though, maybe I'll fly this afternoon.
Take care, MikeB

JettPilot

My Feedback: (6)

That is kind of a cop out. Some props are clearly superrior to others, and some have horrible efficiency.

APC is one of the best props you can get, it turns power into thrust better than most things out there.

There are people out there that like Yugos, Dictators, and many really bad things. That does not make them right. Just because some guy likes an inferrior prop, that does not make it best for him, it just means that he is not to bright.

JettPilot

Hobbsy

My Feedback: (102)

Not all of us are convinced of that, no matter how preachy you get, it just ain't so.

blw

My Feedback: (3)

JettPilot-

I think he meant something like general preferences like sport flying, or pattern, or whatever. Some people really like wood props and it's their hobby to enjoy. I like the black blades with white tips of the MA even though I'm not using them now. What's inferior to your enjoyment is superior to some people. Performance isn't everything to a lot of folks. Truely bright people get this concept!

Tom Jones

My Feedback: (4)

blw,Here,here!!Tom

JettPilot

My Feedback: (6)

When talking about a the best prop, most people want the most thrust for a given amount of power, which is usually APC. Its that simple.

Sure some people prefer old fashioned wood props, but this does not make them better. When these throwbacks from the past say that wood is "best", they should be honest enough to post that wood props are inferrior in turning power into thrust, and that their plane will not perform as well. I have never seen anyone be that honest in a post.

Most people that like wood try to sell them as being best, without being honest about it. That is what I take issue with.

JettPilot

William Robison

My Feedback: (3)

JP:

The APC may possibly be the most aerodynamically efficient prop line available to modelers. But I prefer not to use them.

One, our aircraft are normally so ridiculously overpowered we just do not need a really efficient prop.

Two, there are two types of fliers using props: those who have stuck their hands in the prop, and those who are going to. Using a Master Airscrew or similar prop you will have blunt trauma, some bruises and maybe torn skin. The APC with its sharp tip and leading edge will make multiple slices to the bone. Much more damage, longer to heal, and a lot more expensive when you have to call the neurosurgeon.

The final nail in the APC coffin – there is a spread sheet model called “Prop-Power” that works very well to predict engine and propellor combinations. While the MAS props are rated as the standard (and lowest efficiency) the APC only beats the Mejlik-N and our good old MAS. The standard Mejzlik, the MenzS, and even the lowly Zinger have a higher rating. Best of all? Graupner.

Here’s the rating list from the SS model in order of increasing efficiency:

MAS 1.00
Mejzlik-N 1.12
APC 1.15
Mejzlik 1.18
Zinger 1.20
MenzS 1.31
Graupner 1.45

I use mostly Zinger and MAS, with a few Graupners in the mix.

Bill.

jessiej

Honestly, trying to equate an individual's preference in model airplane propellers with that person's intelegence sounds pretty stupid.

jess

SigMan

My Feedback: (21)

now jess, you sound like a very honest fellow....lol !! [sm=lol.gif]

JPal101

My Feedback: (32)

Ok lets get back to business, I just started using the Klotz in my fuel and what a mess, I guess it is worth it. My question is how much ARO do you inject into a 100 or 125, I have a suringe and can meter any amount.

Thunderchild

Intelligence versus Prop efficiency. New concept dude.

Most of our retired club members are on fixed incomes and prefer the MAS props due to their "tarmac tolerance". You bash the ground with an APC prop and its history. You bash the ground with an MAS prop and it lives to fight (flight) another day. Much cheaper option for these guys. Efficiency has nothing to do with it (though I like your chart comparison Professor Bill)


Of course INTELLIGENT pilots probably never have to worry about making a mistake with resultant prop strike and also may well be rolling in greenbacks so have thousands of replacement props to choose from. The lesser mortals amongst us plan for mistakes and buy robust machinery to compensate accordingly. The MAS prop is a fine example of this planning from old grey heads.

Pretty intelligent thinking from our wizened old folk I think.

Me? I use APC, Graupner and MAS as the fancy takes me but then, I'm not retired - and I only ever said I grew old but I never said I grew up so I guess I'll never qualify as intelligent. [8D]

TC

DandGMartin

Hi Guys, I've been mining this great vane of knowledge and experences for the better part of a year and have found a bucket load of great information. Thanks to all for their contributions. I was given (yes given) a Saito FA80 by a good friend. I really like it a lot, I have changed it to ceramic bearings and outfitted it with a viscosity stack and a blu line filter. It sure handles my UCD 46 well. Sad news, today on my third takeoff run I heard a noise like when a motor kicks a prop loose and then it died. Upon bringing it home and tearing it down I found one of the bolts that holds the clyinder to the case missing. When I removed the remaining three bolts the corner of the case where the bolt was missing fell off. I don't see any other damage. What could have caused this and what else should I look for and expect to order to repair this jewel of a motor.
Thanks for your inputs.
Don

rajul

My Feedback: (58)

Don, the engine could have had some crash damage by the previous owner?

fiery

My Feedback: (2)

I can't get over graupner props being more efficient than APC's ...

Are we talking about the graupner grey nylon props?

Also, I wonder ... there are a few APC blade profiles ... the narrow blades are pretty different to the wide blades (ie APC 18x8W).

fiery

WRM

How do I get in to Club Saito, I have two 82a & 125a.

William Robison

My Feedback: (3)

Teryn1:

Sorry I’m so long getting back to you. There is no simple timing tool for the FA-325R5 radial; all \five cam shafts have to go in at the same time, Saito has some sort of jig for the assembly, lacking that it’s a real bear. It can be done, but the first one or two you put together are going to be a pain.

If you are very careful (and lucky) when you take it apart you can engrave witness marks on the timing gears for reassembly, but you’ll still have to time the gears to the crank. At least you will have simplified it somewhat.

Please note you can get all the cams timed correctly to their individual cylinders and still be wrong – if you set the firing order to anything other than 1-3-5-2-4 the engine will not run well. Post on page 176.

Artisan (and others):

Lessening the load on an engine, when it’s adjusted for a heavier load, will tend to make it effectively rich, not lean. Best example I can come up with is a chain saw. When you set the high speed you have to leave it quite rich running with no load, else it will go lean and quit when you start cutting. This note goes back to page 176 of the thread also.

Tukkus and others:

For maximum strength the muffler head pipe should be screwed into the cylinder as afar as possible; if your pipe is straight with no curve it should be bottomed in the cylinder, if curved bottom it and then turn it out only as far as necessary to get it pointed in the right direction. This is something that hasn’t been mentioned in the notes about the exhaust coming loose, and it should have been. It is not possible for a four thread engagement to be as strong as a ten or twelve thread engagement. This should be obvious, I guess that’s why no one has said anything about it.

If you have the straight machined muffler, you can not screw it too far on the pipe. The cast muffler is different, it should be screwed on no more than about 3/8’ deep – the pipe can go too far and hit the opposite side, this will increase the back pressure at high throttle. Again, page 176.

Les:

Detonation doesn’t happen at idle. Preignition yes, almost without exception caused by the mixture being too lean or the engine overheating. Page 177.

Stall:

A MAS 12x6 three blade prop would look very good on that plane. They are what I’m running on the FA-82 engines.

JPal:

Three or four cc of oil should be enough ARO if you spin the engine up with your starter after its injection to be sure it gets all through the engine.

Klotz supplies pure synthetics as well as synthetic/castor blend – I’ll assume you’re using the blend.

If you’re getting excess oil from the breather line you may have more oil in your fuel than needed. I stay at 18%, but some have gone as low as 12% and claim no problem. If you decide to try less oil, keep the castor around 4% and cut the synthetic only.

Also, careful placement of the breather pipe can make most of the oil blow away from the plane. Takes experimenting.

DandyDon:

No words of wisdom concerning the cause of your case fracture, but I’d ask Horizon about it. They might be willing to help since this is a truly unusual break. Cracking around the mounting lugs is the normal area of breaking a case in a crash.

Fiery:

I’m sure the relative numbers on the props are generalities, as you point out a different blade shape will change things.

And yes, it’s the grey Graupner props.

Regarding [prop efficiency – “Everybody” says three blade props are bad. I fly three bladed props almost all the time. The only plane I’ve found to work better with two bladed is my little Tiggerkitty. It does work better with 6x3 two blade props than with the 5x4 three bladed ones. I think this is because of the greater disc area than having one more blade. If there were a better selection in the small sizes I might have found a 3b than works as well as the 2b of larger diameter.

Picture is part of my 3b stash, the ones from seven to sixteen inch diameter. With these I have the ability to try several different ones and pick the best. Props include Tornado, Zinger, Graupner, and even one 11½x8 home made wooden one.

Bill.

>>EDIT: Forgot to add the picture. wr.

William Robison

My Feedback: (3)

Barber:

You’re in.

Latest additions:

379 teryn1-RCU
380 les40
381 DandGMartin
382 barber 701

Welcome all.

Bill.