Funtana + Four Stroke = Cool!

13-04-2004

Finally got some flying on my Hanger 9 Funtana 40S tonight after fitting an ASP 91 four stroke a while ago. Previously it was fitted with a Thunder Tiger 61 Pro two stroke.

Well, let me tell ya, this finally clears up the argument for me over whether two stroke or four stroke engines are the best for 3D flying! Four stroke wins it hands down!

With the two stroke 61 I could barely hover and the pull out was gonna end in disaster sooner rather than later. Throttle response was pretty good and clean but didn't translate into thrust somehow. This is difficult to explain but those who're flying their 3D models on four strokes after using two strokes will know what I mean. There was also a problem with the engine leaning out when inverted - not a problem - but it's like someone else is controlling the throttle!

Ah, but the four stroke! What a revelation. Despite the fact that its about one bhp LESS powerful than the two stroke it hovers easily and climbs out with authority - plenty of go even despite the fact that I'm using a 14x6 while we're running in AND she's really, really rich. What this motor is gonna be like when it's run in and using a 15x4W I just can't imagine! Should be a rocket! A big efficient prop' makes a huge difference, couple that with torque and you have exactly what you need for 3D.

The next thing is controlability. You ask for a bit of power and you get it immediately. It just provides the thrust exactly when you want it. It makes all the usual pattern type manoeuvres a sinch - in fact it seems odd to be throttling back on the vertical manoeuvres. Superb. AND it sounds absolutely great. I'm sold...

15-04-2004

Well, now I've got a bit of flying in with the Funtana all the much reported wing mount faults are appearing. The wing dowels have worn with the vibration and the wing can move on the wing seat - makes for scrappy flying when your wing incidence keeps changing!

Also the wing can move side to side at the rear so...

Fitted block infill to the wing bolt cross-spar so the rear of the wing actually bolts down to the infill. Side to side movement cured.

Fitted 10mm alloy tube over the wing location dowels and bored the former to fit. Soaked the periphery of the holes with thin CA to toughen the wood. Also added a ply patch behind the former at the dowel holes to give more support area to the dowels.

This , hopefully, will cure all! The engine continues to improve, by the way, and will soon have enough running on it to fit the 15x4W. I'll let you know how that goes.

adzam · 15-04-2004

all seat of the pants stuff m8,

15-04-2004

If you only knew mate, if you only knew...

19-04-2004

More Funtana news:

That wing dowel modification has cured the terrible tuck under in knife flight. A slight increase in wing incidence did the trick. There's still a bit of roll couple but nothing serious.

The new ASP 91 four stroke has become a bit finicky after running in and, as its finale, it threw its prop off today! Anyway, remembering previous four strokes, I removed the silencer pressure to the tank and spent the rest of the afternoon setting up the carb to suit. Now running great throughout the whole flight with much sharper throttling.

Falling in love with this aircraft. It's gone from a complete dog to my current favourite, and it was all down to the motor and aircraft set up.

23-04-2004

Latest update: Now running the APC 15x4 prop', and what a difference! Much better pull and acceleration. Hovering is easier too with sharper acceleration on pull out. Little vibration compared to the 14x6 Master I was using previously. It's also a terrific airbrake in a dive with the engine at, or close to, idle. All good news with the APC it seems, until you factor in the price - £14.25!

adzam · 23-04-2004

love the sound of those 4 strokers

shame you cant get a decent priced one for cars

23-04-2004

Yes, Adzam mate, don't we all! The killer is the price we have to pay for them, but, as you say, nothing else even comes close for that wonderful relaxing, realistic sound. Superb. If I could afford them, I'd use nothing else!

Just the very thought of having to go electric leaves me cold. Bloody airbourne food blenders!

Mind you, in view of the fact that the electric motor is never going to quit in flight you could always use a personal stereo with earphones playing a recording of the engine noise of the actual full size aircraft! Hehehee.

17-05-2004

More Funtana news:

Hanger 9 seem to have a problem with their plastics! First the lower engine mount (glass filled plastic) broke off through an engine mounting screw hole. Rang the local model shop where I bought the model and got, "Ohhh, dunno mate, could take a while to get a replacement." In model shop speak that'll mean six months then!

So made my own up from half of a two piece aluminium mount. It's about an ounce heavier, but is quite nice actually.

Next thing is while working on the mount I notice that my wheels seem to have holes in them five times bigger than the axles! On investigation it seems the centres have disintigrated leaning the spokes running on the axles. One I got them off you could see the plastic is crap stuff. Replaced them with nice soft wheels with good centres.

Took it out and flew it tonight and it seems the same as ever with perhaps a little less vibration. Spongy wheels are great, really work well. Engine mount is much stiffer and I didn't notice the extra ounce when flying.