Mill:

I got two of the Hobby Shack special deal RCM 40 sets.

When I saw the magazine ad I got on the phone, and in spite of my immediate response they told me I was #281 on the back order list. Got mine about three months later.

Bill.

I have a TT 46Pro and a TT 42GP. I love the TT46Pro for its power and easy starting. This motor seems to run and run with little or no fussing. The GP is new but so far it starts well and is going into my Hanger 9 Solo trainer. The 46 is in my Midwest starduster.

Several years ago, I had an OS-40FP and bougt TT 40GP. I got excellent much better performance from the TT engine than I did from the OS. I then bought a TT Pro46 and was amazed at the performance. I only compared it with one OS-46FX and it performed better. I will not use this to say that it is a better engine but simply to express my experience. I bought a second Pro46 and later bought a 42GP. All of the engines have given excellent service and the price is very reasonable.

Hey guys,

I ran a search in the engines for sale section for this engine and found someone about 2 months ago who was selling one but didn't seem to sell it. I then wrote to him and asked if he ever sold it and he said yes, but that he had another he was getting ready to sell. He said that he had about 4-6 hours on it and ran it kind of rich for longevity. He still had the muffler and paperwork on it and is willing to sell it to me for $58 bucks including shipping! I told him I'd take it.

I think I'm going to start on building a spad Debonair and at the same time finish the aerostar kit. Then atleast I get to hurry up and fly!

Could anyone out there give me some quick pointers on upkeep for this engine? I ask this because he said that he ran it rich and I wanna keep the engine running good for as long as possible.

Nuke:
Yeah, that sig that I made from Woodsy's saying is pretty sweet. Thanks again Woodsy for the advice.

Thanks Everyone,
James

Has anyone had any experience with the Super Tigre .51 Ringed engine for use in a Sport 40L plane low wing trianer plane. Is this a high quality long lasting engine that runs reliably that can give a good amount of power for low weight. Or is the O.S. Ringed better - but it's $50 more.

Basil:

The Italian built ST engines were very good.

Production has been moved to Red China, the jury is still out on the new production.

I see no reason to think they will not be as good as the Italian ones, though. The Magnum engines are made in Red China and I have always been pleased with them

Bill.

If I purchased one now I think it would be the italian one - correct me if I'm wrong but I heard they haven't produced the SP's in china yet and the china ST's will be out in late summer.

Basil:
You are probably right.

But a K&B 61 is lighter, and at least as powerful.

Bill.

MockV,

You do realize that there is a possibility that the engine might not be worth 58$ Thats a risk you take buying sight unseen.

You do realize that your only saving $19 bucks when compared to a new one at $77 at tower hobbies

But is the K&B .60 a ringed engine.

Basil:

The K&B model number 6550 is a ringed engine, weight is 17 ounces. I fly them with 12x8 3 blade MAS props.

http://www.modelengine.com/price.htm

Look also at the 61 "Twister" on special for $100 - but that one is an ABC design. Number 6170.

Here are the specs for the three K&B .61 models:

http://www.modelengine.com/aero/aircraft.htm

I have some 6550 engines, an 8360, a couple 4011s, these are all ringed, and have given excellent service. And I have no objection to the ABC engines, I just don't have any from K&B.

But you said earlier that you had already bought the Super Tigre, so I suppose it's a moot point. Unless you are going to buy another engine.

Bill.

The K&B does weigh the same - the ST .51 weighs 12.7 oz without the muffler and 18.3 with. As I'm reading about the ST, I have found that they are designed for overseas where they fly with very liitle or no nitro content. This allows better performance with fuels that have lower nitro levels. At 10%nitro this engine might have great performance. could be a money saver also.

Basil:

My "Standard" fuel is 15% Omega, this is the blend with castor oil, the pink fuel. When I say standard I mean it. Same fuel in all engines, from the Cox 0.020 PeeWee on my "Littlest Stick" up to the Saito 4-strokes.

The 6550 K&B isn't the most powerful 60 class engine available, but it will run forever unless you mistreat it. I'm sorry I didn't buy a case lot of them when they were easily available.

Bill.

Hmmm...ran rich for 4-6 hours...not my idea of a good break-in for this engine...or for longevity...buy a new one and get a three year warranty.

TT PRO .46's need to be broken in HOT...one click shy of full lean for two minutes with a 9x6 prop, then go to a 11x5 and run it through 3-4 tanks at full throttle a couple of clicks lean past the rich/lean break setting. It will just keep getting better after that.

After any running ALWAYS use an after-run oil. I will typically fill the carb venturi with oil and then work it into the engine. Then let it flow to the head and then drain off the excess through the muffler.

Engines treated in this manner run flawlessly and seem to last forever.

So the break in for the ST 51 Ringed will be nothing like the TT F91S four stroke I just brioke in. Took me 1 gallon of gas and it still is a little rough and hunting. But had started to improve greatly on that last tank.

Basil:

Generally speaking, break-in for a ringed engine is moderate rpm, rich, with short bursts at peak rpm, lengthening the high rpm bursts until the engine will hold at peak. The older lapped piston engines were done the same way.

ABC engines, if not kept hot will bind and wear rapidly. They MUST be broken in at a point close to max lean or they stay too cold. Use a fairly small prop and let them wind. Leads to best engine life.

Bill.

So the break in for a ringed 2 stroke is very simular to a
4-stroke engine. Your running very lean at low RPM's untill you wear in the rings then lean up and as you run a few tanks through it, pushing the throttle reving the engine after a few tanks.
How does engine vibration factor into the break in. If there's some vibration at higher RPM's are things still tight or just adjustment problems. I am getting some vibration on my TT91 at four stroke (at higher idle) even after 1 gallon of break in.

Basil:

Break-in methods are dependent on cylinder/piston type, two or four stroke has nothing to do with it.

There are three schools of thought on vibration and balancing:

1) Balance everything, including the spinner. This is the way I do things, and I don't have vibration problems, new or well worn engines.

2) Find the heavy blade of the prop, and install it with the heavy blade down when the piston is up. Some people claim excellent results this way.

3) Forget balance, bolt the prop on and go. This is the method most people use. And they seldom have trouble caused by imbalance.

But I would suspect your TT 91 has a balance problem.

Bill.

Is there a quick way to find the heavy side of the pop by using a screwdriver or some other tool easily available. I have never used prop balancers. I'm going to switch from the Master Airscrew to an APC 14x6. You cant even get a spinner to work with the MA there isn't any shaft left for the nuts when the spinner backplate goes on the prop hub is so thick. It did look like the MA's tips were moveing forward and backward a hair on 5k RPM's, I just thought it was because the engine was loading up.

Basil:

Not terribly accurate, but better than nothing is to look through the hole in the prop hub to center it on the shaft of your srewdriver. You can get a rough balance check that way.

Great Planes has what they call the "Fingertip" prop balancer, costs a little over $4, and works well.

For reasons of appearance as well as noise, my prop of choice is the Master Airscrew three blade series. I've not had spinner fitting problems with them. Perhaps your engines just don't have long enough threads on their cranks.

Again, because they're noisy, I use the APC props only where I need their high efficiency, ie on "3D" [lanes.

Good Morning.

Bill.

I just got the Master Airscrew 3blade 13x8 for my TT91 that will allow a spinner. I might just go with that prop because the engine will be going on a H9 P51D mustang. I'll pick up the $4 GP balancer. That's a good idea of putting the heaviest side of the prop down when the piston in the up position.

Basil:

The TT91, MAS 13x8, and the H9 Mustang should be a good combination.

You might find the engine will idle better also, due to the greater rotating weight of the 3 blade prop.

Bill.

I have had some issues with my TT.46 with the idle -- perhaps need a hot idle-bar plug (Fox or K&B?), rather than stock Tower plug?
pj