onetrack Posted February 2 Share Posted February 2 A GX390 Honda single-cylinder industrial engine, producing 40HP?? For how long?? They produce 13HP in their industrial form! You'd think they could've souped up a V-twin Honda GX690 at least - with twin cylinders and 688cc, there's better inherent balance, and more cubic capacity for upping the power output. 1 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 2 Share Posted February 2 100Hp/Litre is pushing that engine. Nev Link to comment Share on other sites More sharing options...
onetrack Posted February 2 Share Posted February 2 Nev, at 40HP for 460cc, that's just under 87HP per litre. Still a lot of output for a little industrial engine. The single cylinder level of vibration would be my main concern, in such a lightweight airframe. Link to comment Share on other sites More sharing options...
Garfly Posted February 2 Share Posted February 2 Okay ... but to be fair, it is called a Thump-Air (from Chaos Concepts ... powering the Badlands ;- ) 2 Link to comment Share on other sites More sharing options...
Litespeed Posted February 2 Share Posted February 2 I guess the weight is the issue. I agree the v twin would be much nicer for nvh. 1 Link to comment Share on other sites More sharing options...
BrendAn Posted February 2 Share Posted February 2 There is a Honda v twin conversion used on legal eagle I think. 1 Link to comment Share on other sites More sharing options...
turboplanner Posted February 2 Share Posted February 2 Singles are fine on space frames, just a matter of what material and dimensions the space frame is, and what the engine mount design is, non-flex being the best. 2 Link to comment Share on other sites More sharing options...
Garfly Posted February 2 Share Posted February 2 (edited) Here's Kid Khaos demonstrating a prototype and explaining/defending his concept in the YT Comments (Watch on YouTube to see them). And here he is doing some crow hop flight testing. https://www.youtube.com/watch?v=swBVXPkzWUo Edited February 2 by Garfly 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 3 Share Posted February 3 (edited) I would have thought 390 would be it's displacement. A singe without counter rotating balance weights would be rough. WITH weights it would be heavier. Often FLAT Twins are rough torsionally as the pistons stop and start at identical times' and they have offset cylinders. A Vee twin is better in that respect. An angle around 67 degrees is near optimum. You'd still have to determine the engines best balance factor. It's a long time since ordinary cars had SINGLE cylinder motors but they had BIG flywheels to smooth the pulses out. Nev Edited February 3 by facthunter 1 1 Link to comment Share on other sites More sharing options...
jackc Posted February 3 Author Share Posted February 3 On 6/7/2023 at 2:41 PM, facthunter said: Some people taught themselves to fly on the Plane they built and there was no FAA to check anything out for them. A coiuple of Brothers named WRIGHT. and others. We've gone a bit from that and all fighter pilots etc were trained by "INSTRUCTORs' who hopefully Knew what they were doing. This process stops people finding out a lot of things the HARD way. With Aviation you can learn by your mistakes but chances are you won't live long enough to make them all. You also don't have to work out what makes a plane fly and be able to be controlled. There's NOW plenty of information readily available. All that's left is the basic structure and testing sample and sand bags will do that.. A slow plane is not likely to suffer flutter either and lands at a speed you could almost run at. Nev IF you are smart, study a lot of YouTube videos that are now out there AND have a decent paddock and others surrounding your take off and landing location. Look at wind conditions, with a few bunny hops and NO Instructor, you have a very good chance to teach yourself to fly an Ultralight and do it well, with careful practice. The way our sector of Aviation is going, I don’t blame anyone for giving it a go, in our current declining regulatory environment, sad but true 🤢🤢 Link to comment Share on other sites More sharing options...
onetrack Posted February 3 Share Posted February 3 Nev, the Honda GX390 is 390cc in it's original form, they bore them right out, and fit new steel cylinders, and then stroke them with a new crankshaft. So the engine goes from 390cc to 460cc. https://www.nrracing.com/searchresults.asp?Search=460cc&Submit= 1 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 3 Share Posted February 3 I think you are going out on a limb doing that with an Industrial engine A reliable GENSET engine might be a good start. The NAME on the BOX doesn't tell you who made it and from where. these days. I'm seeing good Chinese brands being used by good name companies. I have a LONCIN engine in a ride on zero turn and It's fantastic with 250 hours on it now. 24'5 HP. Nev 1 Link to comment Share on other sites More sharing options...
jackc Posted February 3 Author Share Posted February 3 6 minutes ago, facthunter said: I think you are going out on a limb doing that with an Industrial engine A reliable GENSET engine might be a good start. The NAME on the BOX doesn't tell you who made it and from where. these days. I'm seeing good Chinese brands being used by good name companies. I have a LONCIN engine in a ride on zero turn and It's fantastic with 250 hours on it now. 24'5 HP. Nev There are many offerings, the VTwins also offer a solution, too https://www.aero-news.net/index.cfm?do=main.textpost&id=63F35D18-EDC6-45F4-99FC-0AC80745BEE4 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 3 Share Posted February 3 Yes I've been watching them all along. Note you reference is dated 2019 and there are more options now than then . Also a few HOPEs have died and we'll keep looking. The BASI motor has to be sound and worth spending time and money on it. Nev 1 Link to comment Share on other sites More sharing options...
Garfly Posted February 3 Share Posted February 3 12 minutes ago, facthunter said: I think you are going out on a limb doing that with an Industrial engine A reliable GENSET engine might be a good start. The NAME on the BOX doesn't tell you who made it and from where. these days. I'm seeing good Chinese brands being used by good name companies. I have a LONCIN engine in a ride on zero turn and It's fantastic with 250 hours on it now. 24'5 HP. Nev As far as I can tell, it's basically a one man operation. One guy with a passion. Here he (in orange) is taking on some of the YT critiques: @andrekemp5059 2 months ago Nice HONDA @kidkhaos6427 2 months ago There are exactly zero parts of this made by Honda. Yes it is loosely based on a Honda. @andrekemp5059 2 months ago @kidkhaos6427 Ok. So is it Chines parts or car parts in there. Because Honda crankshaft and piston rod are great and high quality. Koyo bearings. @kidkhaos6427 2 months ago There are very few chinese parts, but yes a couple. Most are US made from various racing industries or here in my shop. Every part and specification is important and I have not just simply put a prop on a generator engine here. I have gone through several iterations of this to reach successful reliability and power delivery. I have tested multiple combinations of valves, pistons, camshafts, carburetors, exhaust configurations , and so on. The engine you see in this video actually now lives in a box in the attic. It was brutally murdered between the test stand and two different airplanes. I have also revised the reduction drive design since this video was made. This is simply a snapshot along my journey. 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 3 Share Posted February 3 We ALL tend to do this sort of thing if we are Engine Possessed type of people. (REVHEADS) I had a Fiat 760 doing 10,000 RPM at 100 MPH and Other engines putting out 4 times their original power. I've got that Out of my system now Had plenty of big engines fail in planes so the Love /hate relationship turned more into waiting for the next blow up and some form of HATE. A piston motor has personality but putting a stethoscope against parts of it when running would really concern you with the dreadful noises you will hear. It's all tortured metal and has to be done very RIGHT to do the job in a plane. A Clapped oily motor can get you to the Pub and back for years but in a plane it has no place. Ther's plenty of things to go wrong without having a dicey motor in flying. I'd still fly an original very old primitive engined plane but only from a suitable airport and surroundings . Balance the ODDS. A jet engine has no personality at all. It's somewhere between a blowlamp and a reversed vacuum cleaner Nev 2 Link to comment Share on other sites More sharing options...
Garfly Posted February 3 Share Posted February 3 A rival forty-horse, 4-stroke, one pot screamer is the Airtech AERO1000: AERO 1000 HO ENGINE PACKAGE – Air-Tech Inc. Ultralight Aircraft AIR-TECHINC.COM 1 Link to comment Share on other sites More sharing options...
facthunter Posted February 3 Share Posted February 3 I'm not surprised by the short life. A speedway bike engine lasts a lot less time You get the performance and have low Mass It's at the peak and you decide if that's what you want. A top 4 stroke single Motorcross does about 200 hours and it's NOT flat out all the time. Nev 1 Link to comment Share on other sites More sharing options...
Garfly Posted March 26 Share Posted March 26 1 1 Link to comment Share on other sites More sharing options...
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