G'day Oily hand people.

I bought a little Airsail Heron Gas Buggy of a friend a couple of days ago. It came with a free engine - a little Silver Swallow 1.5 with a cute pinkish anodised head. I fired it up yesterday. Gave it a prime through the port and a couple of drops down the venturi, a few flicks and it fired so I increased the compression a little and it was soon running on the prime. Filled the tank and away it went.

I know these are not exactly the height of the diesel makers craft but so far this little engine runs very well. I am still giving it short richish runs but it looks like it will be a useful little engine for the Gas Buggy.

This particular model was built by a long time modeler and has been built with more elevator area and a larger rudder than shown in the plan. This should help me to control it in flight. The other one I have I built to the plan and it is just about impossible to control with its very small control surfaces which are really only trims.

I found my Gas Buggy very sensitive to power. Too much and it would dutch roll severely. I tried it with a Taipan Tyro 1.8cc diesel and this was *way* too much. I ended up flying it with a Gilbert .07 which was about right. The fin is too small for the amount of dihedral on this design, but it can fly very slowly with the undercambered airfoil.

G'day John. You are absolutely right. Dutch rolled all over the place. Crashed twice but it seems to be a tough little fellow. I might have to put the prop on backwards or decompress the engine a lot. It is certainly unstable at about 90% power.

This one has been modified by Col from Wombat. He has divided the horizontal stab into two and made half into elevators and he has increased the size of the vertical stab and cut it in half too. The original Airsail surfaces are really small. I have another one with a small electric in it and it flies OK but it is barely under control and has a huge rate of sink. I tried packing the leading edge of the wing up but I suspect I need to pack it up even more.

Is your club in a large paddock with some transmitter towers in the distance near Mitchell and Watson? My son lives in Watson and we dropped in when I was in Canberra one Sunday but there was only one bloke left playing with a large electric conversion of a pattern ship. I must call in again some time when I am in Canberra again. If you came to the Diesel Day in Cowra last year I was there selling some of my PAWs.

Mike,

Can't say I'm familiar with the Silver Swallow 1.5, as such, but I have a pair of Jin Sheng 1.5s from the same factory. The more recent Silver Swallow and CS engines seem a bit prettier, but still about as useful as the SS or JS earlier editions.

To sum up: they work, about as claimed in the instruction sheets. If you need something else, look elsewhere. The Silver Swallow 2.5cc (actually claimed as 2.47cc) engines worked, but were not exceptional either way - bad or good - but were dependable.

You may have a very enjoyable combination! Enjoy it so long as it iS enjoyable...

Hobbies are for fun: ulcers are for proffesions.

G'day

I agree, they are not great engines but as this one was "free" I am not too worried. The main problem here is not the engine but the plane its self. It is a bit on the tail heavy side I suspect and the mods to the control surfaces have made them a bit too powerful and worse, the vertical stab is not quite straight. Still, it is fun to play with.

I do have several other small diesels. I have a PB 033 which is a gem, a Taipan Tyro which is well worn but goes OK, a PAW 1.5 single ball bearing R/C which is in a Dalaire 50% and which works really well, A PAW 15 RC in a Sig Kadet Seniorita which is great so long as there is not too much wind around and a PAW 35 R/C which is looking for a suitable home. I still have a Super Tigre G2015 D which I made from scrap parts back in the 1970s and which we used for ages for a rat racer. It still runs well.

I am also waiting for David Owen to release his reproduction Taipan 15 and there is a rumour that Peter Burford may also be going to do a run of a repro early Taipan. Good usable early Taipans are becoming hard to find these days and often bring extremely high prices on a certain auction site.

My SS 2.47 is a decent sport engine...nothing special.

George

Mike,

try it with a 10X4 prop and undercomped, so it just puts around.

A mate of mine is finishing off a Humbug for the Vets Day (2&3 May - Muswellbrook). He's using a 1.5 Taipan with a similar prop so it just kind of PhttttS about.

G'day

Thanks for the info. Will try ASAP. I figured I would have to do something like this but I had no idea of the actual details.

A question if I may - would an electric 10 x 4 prop be better than a normal "glow" one as it is lighter. After all, it is not as if it will be revving hard or as if it has a great deal of power. Just wondering. Or a wood prop?

Hi George, I have 7 or 8 SS 2.47s, two are Jin Shi versions. The Jin Shis have a larger crank with a larger transfer port.
One of them is in a Dumas Tomahawk, and it's special because I taught James Zchou to fly control line with it.
James had about 45min. training with a Mackey's control line stunt kite first. That Dumas Tomahawk is over 25 years
old and had been powered originally with a LLLAM 2.49cc diesel, then three different SS 2.47cc diesels before installing
the Jin Shi. I fly it on 60'x.015" lines and use a 9X4 Taipan. Both Jin Shi's turn a Taipan 8X4 14,600-14,800 rpm. Mr
Gau told me the SS 1.49s were based on the middle 1950s Webra 1.49 engines. I've got one SS 1.49 but it doesn't
have much time on it, it didn't want to rev up without vibrating. Mine has an incredibly heavy unbalanced piston etc....

Tony G

G'day The little SS 1.5 that started this thread is quite a sweet running little engine. It was extremely easy to get running, easy to tune and while no Super Tigre or Oliver Tiger Cub was quite powerful - too powerful in fact for the little Gas Buggy. I was quite surprised at how well it ran. I had the 2.47 version some years ago but I did not ever get round to running it and it moved on via a certain auction site which shall remain nameless.

Hi Mike,


Yep, thats my club. I live the other end of Canberra in Tuggeranong, but the Belconnen club has more old-timer modellers so that's where I go.

I remember you from the Cowra diesel day. In fact I think you might have bought my PAW .35, right? That was a good day, I hope they do it again.


cheers,
John VB