Bluehawktechnologies Posted September 1, 2008 Posted September 1, 2008 Greetings everyone This may sound very odd. I have four Victa 160cc mower engines (old type) that produce 4 horsepower per unit. I was intending to use them on a design I have been working on,But I have a few little questions though. * What size prop can these safely use I have been looking a 28 inches. * Would they need a ratio box or is Direct ok The ultralight would have four of these motors mounted on the wings. This is just as a side project to keep me busy Has anyone else used or considered to use these engines? In my engine tests I got 4 horsepower from each motor and a fuel rate of 500mL/Hour/engine at running speed. Well any help would be good Thanks
Guest palexxxx Posted September 1, 2008 Posted September 1, 2008 Sounds like a fun project. Good luck
Guest J430 Posted September 1, 2008 Posted September 1, 2008 you are kidding me....right??? 20-30 years ago the founders of RAA were doing exactly this and many of them shortened their lifecycle rather successfully! What ever you are thinking, fit a Jabiru/Rotax/Lycoming/TCM or some other well proven U/L engine or you may end up like this........... J ...... (Raining on the parade of Bluehawktechnologies)
Bluehawktechnologies Posted September 1, 2008 Author Posted September 1, 2008 the aircraft would not use a single 160cc but four 160cc engines. Jabiru/Rotax/Lycoming would not scale well into the airframe. as for the TCM I will have to look that motor up. I have a Lycoming 350Hp Blue motor sitting in my Garage as a spare for one of the company's aircraft but I am not going to waste such a motor. This is a scaled four engine WW2 bomber with a wing span under 10m. Currently it is a cozy 600mm wide and 5600mm long and weight all up is under 300Kg. I have heard of the accidents the single engined aircraft had and took note what motors/carbys were used. These engines are third generation not first/second generation and the Carby systems are different. This is being built as a fun little toy for weekends play.
Flyer Posted September 1, 2008 Posted September 1, 2008 I was under the impression that ultralights or RA-Aus machines were restricted to 1 engine. Would need to be VH reg for multi engine... and you would need to hold a multi engine endorsement as well....:thumb_up:
Bluehawktechnologies Posted September 1, 2008 Author Posted September 1, 2008 I was under the impression that ultralights or RA-Aus machines were restricted to 1 engine.Would need to be VH reg for multi engine... and you would need to hold a multi engine endorsement as well....:thumb_up: I personally am qualified for Fast Jets and Helicopters for my company. We operate Military Class aircraft and Ex Military Aircraft. So that side I am covered and as for VH registration I am not 100% sure. I have seen CASAs requirements for strength of the airframe/wings and so far we have surpassed them,We have made many scaled aircraft for fun in our South African office and being ex military we tend to go troppo in regards to making it strong. Our test wings we piled 950 Kg in the ends of each wing and it still did not bend. The airframe is made of Aviation Aluminum,Foam,Fabric (control surfaces) and Perspex The foam is very handy for the leading edges and being fire retardant it is also handy for around the fuel tanks. Most aircraft have one or two wing spars This project operates two box spares and a tubular spar.
Guest J430 Posted September 1, 2008 Posted September 1, 2008 You could do it under the EXPERIMENTAL category. See the SAAA. I am sure you will get it to work somehow but the airframe to support the 4 engines etc etc etc....... may end up needing more HP! Victa did make these though......... http://www.airtourer.asn.au/main.htm J:thumb_up:
Flyer Posted September 1, 2008 Posted September 1, 2008 Sounds like legalities covered so lets look at the rest. The victas are slugger motors I'd think..low revs but reasonable torque. We run a Zenoah 62 in our giant scale pylon machine. The Zenoah makes about 4hp at 8500rpm. It quite happily turns a 22"x10" prop. Some of the other guys run DA100 motors and are up around the 28" and I think around 14" of pitch although dont quote me on that one. For 160cc I'd think that they'd probably only rev to 5000rpm so I'd be looking for maybe about 30" diameter and probably 14-18" of pitch. To keep it simple, I'd use direct drive... We use Bolly props amongst others on our models. Bolly has a website and does a variety of props. Have a surf... Have fun, try not to kill yourself and let's know how the project goes...:thumb_up:
facthunter Posted September 1, 2008 Posted September 1, 2008 Victa 160. These are well made engines but not light in weight. The biggest problem is that they have a cast-iron barrell and this just does not get the heat out, so you need to give the piston lots of clearance and it will still be subject to all the oiling problems associated with running too hot. I suggest you use chainsaw engines, with nikasil cylinders and forced air cooling, or go-cart engines a la Cri-Cri. (Cricket in francaise). Nev
Bluehawktechnologies Posted September 1, 2008 Author Posted September 1, 2008 Flyer I will take a good look at those motors and props you were talking about. I am currently using a wooden prop for tests, facthunter oil wise it is a 2 stroke motor normal operations is 25:1 but I add 10%more oil in the mix for safety. I do not mind the cast barrel and with in behind the prop cooling does not seem an issue. My clearance for the engine barrel is three inches each side I can not use a chainsaw motor because of the aircraft size and its weight (it would not get airborne) I have gone overboard with its structural strength to increase the odds of survivability if it does need to engage in a hard landing,belly landing or collision at least I will be able to walk away
jcamp Posted September 1, 2008 Posted September 1, 2008 Pay to check this but IIRC under 95.10, no of engines (or type) is not specified ie you can have as many as you want.
Flyer Posted September 1, 2008 Posted September 1, 2008 Just a point on oil mix BlueHT.. if you put in an extra 10% oil, your mixture will be 10% leaner and this may cause lean running... I.E. hotter motor than necessary... I used to think that more oil made it safer until a bike mechanic pointed out a couple of things to me.. Just use a good quality oil :thumb_up: I'm not a mechanic so stand to be corrected....
planedriver Posted September 1, 2008 Posted September 1, 2008 I imagine you are right there jcamp, because the Lazair has two motors.
Bluehawktechnologies Posted September 2, 2008 Author Posted September 2, 2008 Just a point on oil mix BlueHT.. if you put in an extra 10% oil, your mixture will be 10% leaner and this may cause lean running... I.E. hotter motor than necessary...I used to think that more oil made it safer until a bike mechanic pointed out a couple of things to me.. Just use a good quality oil :thumb_up: I'm not a mechanic so stand to be corrected.... I use the old Castrol R4 oil (castor oil) this gives good lubrication and prevents lockup. If I use the 25:1 mix straight I am worried about under lubrication of my barrels. I looked at CASAs rules about ultralights and they did not seem to suggest a limit to the number of engines The Cri Cri (french microlight) has two engines
Guest ozzie Posted September 2, 2008 Posted September 2, 2008 I've seen plenty of Victas flying and once they are set up right with a pumper carby they are as reliable as any other two stroke. A belt redive is recommended not only for the extra thrust but the crank has a hard time with direct thrust loads. some turn the engine around and bolt the prop on the flywheel end, similar to my little pioneers on the lazair. there are plenty of aftermarket ign kits to make them even more reliable. early versions seem to produce the best power. I like the sound of what you are building even if you will have to find your own 'area 41' to fly it in. is it a scale B17? Ozzie
Guest Mad Dave Posted September 2, 2008 Posted September 2, 2008 Have you got any photos of this project? Sounds really cool!!
Bluehawktechnologies Posted September 2, 2008 Author Posted September 2, 2008 I've seen plenty of Victas flying and once they are set up right with a pumper carby they are as reliable as any other two stroke. A belt redive is recommended not only for the extra thrust but the crank has a hard time with direct thrust loads. some turn the engine around and bolt the prop on the flywheel end, similar to my little pioneers on the lazair. there are plenty of aftermarket ign kits to make them even more reliable. early versions seem to produce the best power.I like the sound of what you are building even if you will have to find your own 'area 41' to fly it in. is it a scale B17? Ozzie It is a scaled B24 Liberator early model (without the powered turret) I chose to make this one because of its size and no one else has made an ultralight version I will have to look at your belt redrive idea as I am not sure about those types The sizes are Wing span = 9600 Fuselage length = 5600 Fuselage width = 600 Fuselage height = 800 So it is a cozy fuselage indeed,I chose the early B24 due to its perspex nose (this will help landings),Fuselage height and high wings.
Guest ozzie Posted September 2, 2008 Posted September 2, 2008 try finding some old scouts they have what you are looking for, some have robyn 250 with belt drives. the real early ones have a chain drive not very reliable as the chain gets red hot, breaks, flys off and starts grass fires. The belt drive is actually three? narrow belts. they work fine. I will dig around my old files tonight and see what i can find. Ron Wheeler is still around maybe he can help. as i already fly a twin engine ultralight maybe i can get my multi ticket:big_grin: i have thought along the lines of a scale single seat mitchell bomber powered by small radials. but wrong country for that:confused: ozzie
Bluehawktechnologies Posted September 2, 2008 Author Posted September 2, 2008 try finding some old scouts they have what you are looking for, some have robyn 250 with belt drives. the real early ones have a chain drive not very reliable as the chain gets red hot, breaks, flys off and starts grass fires. The belt drive is actually three? narrow belts. they work fine. I will dig around my old files tonight and see what i can find. Ron Wheeler is still around maybe he can help.as i already fly a twin engine ultralight maybe i can get my multi ticket:big_grin: i have thought along the lines of a scale single seat mitchell bomber powered by small radials. but wrong country for that:confused: ozzie The Germans have a 3 cylinder radial engine for light aircraft (but they look pink if that worries you) I have made a few scaled replicas in my company these have been P38 Lightning (we used the German 3 cylinder engines for that) P40 Kitty Hawk ( chev full alloy V8 ) P51 Mustang ( Chev V8 full alloy ) Spitfire ( we cheated with this as we used a clancy skybaby engine ) and now this project. If you wish the web site for the German company whom sells the engines I will find the address for you. ozzie what kind of ultralight do you fly? it sounds fun
Guest ozzie Posted September 2, 2008 Posted September 2, 2008 I fly a Canadian Lazair. It is fun when i can get out and play with it. Not fast but is great for thermalling, ridge soaring and playing my own version of red bull. only burns about 4 lts an hr total. i've just about had enough of the two strokes i want to convert to electric. www.lazair.com ozzie
vk3auu Posted September 2, 2008 Posted September 2, 2008 Back a few years ago, someone had a 4 engine aircraft at Narromine. It actually flew too. Someone on the list should have some details. David
Teckair Posted September 3, 2008 Posted September 3, 2008 This sounds like a interesting project some comments that come to mind are, you and the aircraft will have to be very light and low drag to fly on 16 HP. Under ANO 9510 you can have multi engines. I am not aware of any requirement for a multi engine endorsement. More oil mix in the fuel will decrease your safety rather than increase it. Best to use the highest quality oil. Can I ask how far along is progress with the project? Regards Richard.
Guest ozzie Posted September 3, 2008 Posted September 3, 2008 that was a modified Lazair with four pioneers on it. it wasn't legal. it belonged to a guy called Fanando he ended up taking it back to Portugal. There are some photos on the web somewhere. there are several lazair 'multis' in the US and Canada with a mixture of engines. inboard 185 rotax and pioneers outboard. even a tri motor with the third behind the pilot. ozzie
Bluehawktechnologies Posted September 3, 2008 Author Posted September 3, 2008 This sounds like a interesting project some comments that come to mind are, you and the aircraft will have to be very light and low drag to fly on 16 HP. Under ANO 9510 you can have multi engines. I am not aware of any requirement for a multi engine endorsement. More oil mix in the fuel will decrease your safety rather than increase it. Best to use the highest quality oil.Can I ask how far along is progress with the project? Regards Richard. I am regular weight (ok maybe a little bit more) The airframe itself is exactly like the real thing just smaller (other than the canopy of course) I only added more oil to prevent lockup during the tests. but I have to run some tests with the standard mix as well. I use the same oil that racing go carts use by Castrol. I have completed the one piece wing and 54% of the fuselage.all the framework is completed I just have the long process of fitting equipment. The landing gear retracts to help minimize drag as well. (it is the old windup type similar design to a threaded car jack with gas assistance) My aim is to keep the whole aircraft total under the 350Kg mark. I may have to take up jogging to hit that mark.
Teckair Posted September 3, 2008 Posted September 3, 2008 With ANO 9510 max TKF weight is 300 kg. I am not sure about the experimental category I think 544 kg but I am not sure if you can have multi engines when experimental, maybe not. I don't want to be negative but I think you will run into problems with power to weight issues. To me you have two main issues to consider power to weight and will it fit into a category. Good luck with the project.
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