bob27s

My Feedback: (19)

For what its worth....

I am flying a H9 1/4 scale J-3, powered by a 'vintage' OS 1.20 Gemini twin (forerunner of the 160 twin)

Turns a 18x5 Zinger at 7000 rpm. Will turn a 16x6 up closer to 9000. For the J-3, that 18x5 is my prop of choice.

No, its not a pattern engine, does not put out nearly the HP as a YS120 or OS120 single, and it will not hover my 14 lb Cub..... but the engine is absolutely perfect in this application. It flys and sounds like a real cub, only with a bit better rate of climb With the glow driver (expert) and that 18" prop, the engine idles about 800 rpm.

I would imagine the 1.60 twin from OS, APS or Magnum will work just as well in the supercub, unless you were looking for serious showtime performance.

Bob

iflyj3

My Feedback: (7)

Deleted, sorry about the thread drift.

Phil Heller

My Feedback: (9)

Dr. pepper

Your new 182T should do fine in a J-3. Mine was in a Sig Cap EX and was capable of everything but all out 3D! I used an onboard glo-driver (McDaniels) and Wildcat 20/20 fuel. with the driver I didn't need an auxiliary starting battery as I installed a 2000MaH Battery. Needle vale extension was flexible cable. Vibration? It ran like a swiss watch! could hardly see a shake! Finally replaced it with an OS 160 2 cycle to get lighter weight and more power.

Check it out at http://www.quiknet.com/pheller

Phil

JCOKEEFE

My Feedback: (2)

[8D]It's interesting how these threads evolve. The original
inquiry had to do, I believe, with an OS Gemini 1.60 vs. a
Saito 1.82 twin and now has run the gamut to a 3.20 displacement.
I have an OS Gemini 1.60 twin and it is an EXCELLENT engine.
I currently have it installed in a Stinson Reliant SR9 with a
weight of approx 20 pounds. The prop/size is 18X6X10. It
will fly the Stinson more than adequately at 1/2 throttle.
Forget about 3D, get a helicopter, let's fly!!! This engine is
easy to start and vibration is minimal.

spitflier

My Feedback: (2)

I am also considering a satio vs OS vs magnum any thoughts on the magnum cost is a consideration I also am looking for help with smoke from a twin what mufflers do I use
Steve

JCOKEEFE

My Feedback: (2)

[8D]I have no knowledge of the Magnum product.
Perhaps someone will respond with some good
information about Magnum engines.

William Robison

My Feedback: (3)

Steve:

I've been off line for four days, sorry for the slow response.

The OS 1.60 twin is a fine engine, and it's even better when bought with the Magnum name on it. If you are going to spend the bucks to get the OS label, just add a little more and go for the Saito.

Bill.

PlaneKrazee

My Feedback: (14)

Bill,

Until someone posts rpm data I would not say the Magnum is equal to the OS.

I'm still waiting to read what the rpm data is for the 182.

REDLAWNPILOT

With about 1 gallon of 15 % through my Saito 182t, I'm getting 8000 to 8200 rpm with an APC 18x6. Engine is in a 140 (1/4 scale) tt Giles 202.
Hopefully once it is broken in it will do about 8700 to 9000. Vertical is out of sight. And no it does not shake very much. The sound is much like a Harley at idle.

Jim

William Robison

My Feedback: (3)

Brian:

As most of the parts interchange between the OS 1.60 twin and the Magnum 1.60 twin, I'd say that any rpm variations would be due to production tolerances.

The only real difference I've noted is that while the FEMA starter will bolt up to the OS with no modification, there are a couple nubbins on the Magnum case that have to be cut down to mount the starter.

Bill.

elmshoot

My Feedback: (6)

I am currently running a 1.82 The engine does vibrate a little but no big deal. Nice running engine. We have a guy at our field that has quite a few 1.60's I think mine is a little more powerful but he doesn't lean on his very much. I run 20/20 fuel and at full power it is over 2oz per minute! I have on board glow ignition haven't dropped a CLY in quite a while. If I do I just turn the ignition on. I'm running 2cell setup on the EGass system.
Next time out I'll get some # for you. I did have the linkage between the carbs have one of the rivits fall out. If you want I will describe my fix.
Sparky

alpinestar

Hi Sparky
Saw that you have experience with the saito 182 twin; I have recently mounted one on a GP GeeBee. What a sound!! I have noticed a moderate surging of RPM at full throttle (200-300 rpm) & the needles, particularly the starboard cylinder, seem to be quite insensitive to adjustment. I'm runnng an APC 16x8 with 15% Omega. I seem to get 8200-8500 rpm, with occassional surges to 9000. Any insight you might have would be greatly appreciated!!
thanks
m

elmshoot

My Feedback: (6)

First the setup that works for me.
OS F plug in all 4 holes
YS 20/20 fuel (Wildcat brand)
APC 18x6 wide
around 8.5K RPM
Idle with out glow heat is <2K
I ONLY dial the engine with a Tach. The needles are very insensitive I go to peak on each side then back off about 200 rpm.
The surging could be an air leak. You may be spinning the prop a little too fast as well, try the APC 18x6. If the engine is low time check the valve lash as well.
They do sound neat.
Sparky

JCOKEEFE

My Feedback: (2)

[8D]Well William, I probably sound like your mother. but, why are you promoting
the company that copied the OS 1.60 twin????? I have been an OS user
since I got into the hobby in the early 1980's (long before there was a "Magnum").
Let's forget about price and look at quality. I have been buying and flying OS
4 stroke engines from day one and they have never let me down. I have used
the OS 1.20 Gemini and now the 1.60 Gemini and they are excellent engines.
Shoot, anyone can copy what someone else has engineered and developed!!

William Robison

My Feedback: (3)

Jerry:

The Japs were copying long before the Red Chinese started doing it.

So long as Magnum is making the same engine for a lower price (four stroke) or making a better engine, also at a lower price (two stroke) I see no reason to pay OS' price.

Bill.

JCOKEEFE

My Feedback: (2)

[8D]Are you sure that they are making a better engine??? Also, William, I would, as a
"Community Moderator", just try to be a little more PC. Today, our Asian
friends are referred to as Japanese.

planet4393

hi from oz. i have a saito 2.70 twin, (twin carb/plug/pumped) am having a bit of trouble starting it, starting backwards, throwing props, etc. it has a FEMA on board starter however i am not happy using it as am worried about bending a rod with all the back firing at present. I replaced the origonal saito plugs with os 4stroke plugs and this has improved things somewhat. am using 10% nitro 2% castor 18% syn and balance methonal. energising tyo plugs . should i be flicking thruogh compression ie anticlockwise, or bouncing it clockwise??? any advice would be appreciated. How do you feel it will be suited to the 27% G/Planes Christen Eagle??? thanks for your time Tony Perth Australia.

William Robison

My Feedback: (3)

Jerry:

PC is neither.

As far as Japan is concerned, our word "Japan" comes from the Chinese language, and is in any form "Jap,' "Japan," or "Japanese," an irritant to them. The Wade-Giles Romanization of the Mandarin name for Japan is "Jihpen," common usage ground it down and it became "Japan" in English. The two characters translate as "Birth (of the) Sun." The Japanese name for Japan is the same two characters, but their pronunciation is different. Obviously if you are standing on Honshu the sun does not rise from beneath your feet, not only is their language descendant from Chinese, the name of their land also comes from the Chinese. All of this is a constant irritant to them also. As a nation they are the world's most racist nation, extremely xenophobic, and almost incapable of admitting any other nation or group can approach them in intelligence, education, or quality of production. Have you ever seen one of the older Japanese instruction manuals? A good proof. They wouldn't accept the fact that their command of English was not perfect, that gave rise to the term "Japlish" for the wordings you found in them.

Their word for their nation is most commonly written as "Nippon," but also sometimes as "Nihan," "Nikkon," or a variant. As an example "Nikon Kogaku Shimbun Fukyu" translates into our more usual wording as "Japan Kodak (camera) Company, Limited." Or as you and I see it, "Nikon Camera Company."

None of this is to say their current products, for the most part, are not good quality. My "Good" 35mm camera is a Nikon, the Leicas are just too expensive. The Nikon is another example of excellent quality for a lower price. And their current cars are good, a great contrast to the ones of 40 years ago that were drive two years and toss. If they actually lasted two years.

Also, it doesn't alter the fact that some of their products that used to be excellent both in price and quality, have gone to pot. Some. like the OS ringed four stroke engines, are merely overpriced and still of good quality. Other products have gone down in quality and still have exorbitant prices.

NOTE: On the language comments, I was an Asian language major in college, I've traveled there extensively, and not counting Viet Nam, I lived in the Far East for about six years. I can speak on this subject with authority. How much time have you spent in Japan? I know the Chinese and the Japanese, my preference should be apparent,

OK, "Mother" OKeefe, I've made my argument, it's your turn.

Bill.

William Robison

My Feedback: (3)

Planet:

Starting your 2.70 can be done either forward or with a back flip. If you don't have it "Wet" enough with prime on a cold start it will tend to backfire, but with sufficient prime there should be no problem,

My set-up on the FA-300TTDP is OS "F" plugs in the rear, (These are the ones to heat for starting) and K&B 1L plugs in the front. I'd think your 2.70 would work well with the same combination.

The twin carb engines can be frustrating to get right, a temperature gun is highly recommended for setting the mixture - check head temperatures for balancing the mixture. If the valve lash is off, or the cams have worn unevenly getting good engine run is almost impossible. Set the valves at 0.002" with as much accuracy as you can, then check temps to adjust the carbs.

If you have a degree wheel and a good dial gauge set you can check the cam wear without taking anything apart, or you can actually pull the cams out for a visual inspection. Leave that as a last resort, though.

When it's right a sloppy prime will give perfect easy cold starts, a hot start wont need much more than a touch of the starter.

Finally, the FEMA starter, while strong, is not strong enough to bend a rod in your engine. Don't be afraid to use it,

Bill.

planet4393

Thank you for your promt and imformative reply. I have been energizing the rear plugs, so I will change that, Iput O.S. 4 stroke plugs in and that has improved things somewhat. Good idea about tuning mixturu with reference to cyl head temp, do you think a multimeter with a thermo couple would work ok? more akward no doubt but the principle is the same I guess.Ill let you know how things go. Do you think it would cope with the extra weight associated with a FEMA in a 27% GP Christen Eagle and still be capable of 3D type manouvers??

William Robison

My Feedback: (3)

Planet:

I like the FEMA starters, but I don't like the weight when the starting batteries are in the plane. If you use LiPo the weight penalty will be much lower, but the "Wallet" penalty will be much higher. My way is a jack in the plane for connecting a large battery pack for cranking the engine, and using that I decided the on board starter wasn't really that great. Just use my ordinary hand held starter.

The 2.70 should fly the Christen "Eagle" very well, but you may want to leave the starter out to keep the weight to 14 lbs or less. It should still fly it with the starter and a LiPo pack, but you might not get as much 3D as you'd like. Bear in ind the Eagle isn't intended for 3D anyway.

A multimeter with a temperature probe will work, but the reaction time is much slower than the IR temp gun. If you can get two probes and attach one to each glow plug it should work fine. Just be sure to check them one to the other, there could be a variation there. So long as you know what the variation is it shouldn't cause a problem. One of the reasons I bought my Raytek was tuning multi cylinder engines, it made life much easier. Highly recommended. Price is down to $70 or so now, mine has the laser designator and was $120 when I got it. Should I have waited? No. There are IR sensors available for $30 now, and it doesn't matter if they are 40-50 degrees off in their readings, you just want both heads to read the same. Not intending to say the cheapies are that far off, just that it doesn't matter so long as the one you get is consistent in its readings.

Enjoy the engine and the plane. I think it will make a good combination.

Bill.

JCOKEEFE

My Feedback: (2)

[8D]OK, Bill. You certainly gave me a lesson. Peace to all. Amen.

jaimicook

The Magnum 160 is a very pretty engine, in fact it would look very nice in a walnut display mount. It is, however, not as powerful as the FS120 single. It does, like most twins, require hot glow plugs for reliability. It has a great sound, and really looks nice in an appropriate size airplane such as a J3, an Areonca K, or a Mooney mite. It had, at one time, a problem with the con rod bolts. This seems to have been corrected in later units.
JJ

old-pilot

Mr. Robison; Could you explain in a little more detail your technique using the Raytek to adjust multi-cylinder engines? I have a Saito 182 that is giving me trouble.

I have been using an OS 160twin and the Saito 270 (single carb) for years with good luck but the 182 so far hasn't been flyable. BTW, I have many,many, single cylinder 4 strokes working great.. thanks a bunch..

Roy Courier, AMA5272, IMAA3860, W0SHY

William Robison

My Feedback: (3)

Roy:

If your Saito twin is one of the engines with twin carbs cylinder balance is usually trivial.

First, check the valve lash. If it's off you will not be able to balance the engine's running. Use a 0.0015" feeler. Yes, that's one and one half thousandths of an inch. The metric equivalent is 0.038mm. The factory recommended minimum is 0.04mm, if your 0.0015" strip slides in with a little drag you're fine.

Peak both needles, richen them evenly to get your 300-400 rpm drop, then check the exhaust temperatures after it has run at that setting for a minute or two. Go slightly richer on the hot cylinder, or slightly leaner on the colder one. You should be able to get the EGT really close, and with that, balanced power from each cylinder.

You can also check the actual cylinder head temperature, but the EGT reacts much faster. Just be sure your measuring point is as close as possible to the same place on both cylinders or exhaust pipes.

Some engines you wont even out with mixture alone, that's when you have to play with the only other variable you have - the cylinder's pumping efficiency. You do that by changing the valve timing. Nothing radical like resetting the cams themselves, just changing the valve clearance is all that's needed. And this is one of the reasons we set the valves to minimum clearance, we can still loosen them a little.

On whichever cylinder has the higher EGT, open the intake clearance just a little, and recheck the balance. Keep doing this, you should get it to come in nicely. If you can't balance the engine with the intake alone go to the exhaust and open it up.

If you end up with one cylinder's valves both at 0.004" and the other still at minimum clearance you have further problems. Either live with it, or overhaul the engine.

On the engines with the single carb, the valve lash is the only method you have for cylinder balance.

Bill.