Recent content by MGriffin

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  1. MGriffin

    Low budget Ultralight Aircraft

    I was thinking along the same lines. I shouldn't have to run it at 5000rpm or above very often. Maybe for takeoff and situations where I needed to climb out quickly above trees or power lines at the end of a field, but I should be able to run it pretty close to the ideal 3600rpm (or maybe even...
  2. MGriffin

    Low budget Ultralight Aircraft

    I have a plan. Before I get too in-depth with my design, I should buy the Vegas Carts motor and Ace redrive. If I can get Jan Carrlson, (the prop genius) to help me, I can choose an optimal propeller size. Then I build a cheap test stand to mount all of that on. Then I do some static...
  3. MGriffin

    Low budget Ultralight Aircraft

    You may be right about the altitude power loss being too great. I may have to start looking at other alternatives. On second thought, the VC460 might put out more than the advertised 25 hp since I'd be getting the forged flat top piston. The compression would be boosted to around 13:1...
  4. MGriffin

    Low budget Ultralight Aircraft

    Vegas Carts was very helpful. They gave me the exact specifications for the side cover mounting holes that are near the PTO shaft. The 4 bolts are 3.5" center to center, so they are on a 5" circle according to my rough sketch. This is a very common pattern, and it might be the exact same as a...
  5. MGriffin

    Low budget Ultralight Aircraft

    The people that are going direct drive are using big block V twins. They are using aerodynamically efficient esigns like the luciole. The people using small blocks, like Kevin Armstrong, use aftermarket power mods and redrives. A completely stock small block V twin won't have enough power. I...
  6. MGriffin

    Low budget Ultralight Aircraft

    What kind of performance do people attain with the gx690 direct drive? I wouldn't mind going with a gx690/if it didn't weigh over 90lbs and generated decent thrust. It would vibrate a lot less than the VC460 ;)
  7. MGriffin

    Low budget Ultralight Aircraft

    The valley engineering setup is really neat. But it kinda gets away from low budget at $5495. And it weighs 120 lbs... If you design for the extra weight, then no problem. I've already accepted that something will break on the VC 460 eventually. It definitely isn't the be all end all, and...
  8. MGriffin

    Low budget Ultralight Aircraft

    A completely stock V twin running at 3600 rpm that puts out 25 hp reliably in its stock form would weigh around 100 lbs stripped. You could always try lightening the block. But like you said, you'd start to become your own mechanical engineer. So without modifying your V twin engine, I think...
  9. MGriffin

    Low budget Ultralight Aircraft

    The main issue I have with the industrial V twins is the extra cost and weight. They're a wonderful choice if you have the money, but you'd be looking at at least $1000 for a new V twin. And that would be a totally stock V twin. You'd have to dump probably another $700 into it to get all the...
  10. MGriffin

    Low budget Ultralight Aircraft

    I'm fairly certain that you could run the VC460 with a billet aluminum flywheel. Vegas carts does sell one for $240 http://www.vegascarts.com/product-p/arc6622.htm But if you installed it, you'd either have to resort to hand cranking or an electronic starter. You can't use a pull start with...
  11. MGriffin

    Low budget Ultralight Aircraft

    You're absolutely right Bberson. There is nothing wrong with experimenting, and the only way to know is through experience. We'd all still be in the dark if Thomas Edison was too afraid to test his light bulbs. I greatly appreciate that you are concerned for my safety, but you have my word...
  12. MGriffin

    Low budget Ultralight Aircraft

    Ace aviation makes a redrive unit for the Honda gx390. I think this may fit a VC 460. http://www.aceaviation.co.uk/index_files/Page718.htm I'm going to email VC to see if the front cover bolt pattern is the same. If it is, then I'm going to drop the money for this combination. I'd be looking...
  13. MGriffin

    Low budget Ultralight Aircraft

    I completely agree with what you said Topaz. I'm not going to be flying over the rocky mountains. I certainly won't be flying over densely populated areas. I just want a cheap way to get in the air and have fun. I find it hilarious that the armchair experts use "plastic parts" and reliability...
  14. MGriffin

    Low budget Ultralight Aircraft

    I'm new to this forum, but I've read several threads discussing potential low budget aircraft builds. One of these threads that caught my attention went over the biggest problem (in my opinion) with a low budget aircraft. The engine. If you plan on buying a purpose built aircraft engine, you...
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