• Welcome aboard HomebuiltAirplanes.com, your destination for connecting with a thriving community of more than 10,000 active members, all passionate about home-built aviation. Dive into our comprehensive repository of knowledge, exchange technical insights, arrange get-togethers, and trade aircrafts/parts with like-minded enthusiasts. Unearth a wide-ranging collection of general and kit plane aviation subjects, enriched with engaging imagery, in-depth technical manuals, and rare archives.

    For a nominal fee of $99.99/year or $12.99/month, you can immerse yourself in this dynamic community and unparalleled treasure-trove of aviation knowledge.

    Embark on your journey now!

    Click Here to Become a Premium Member and Experience Homebuilt Airplanes to the Fullest!

Search results

Find deals on ebay
Find deals on amazon
This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.
  1. Lucky Dog

    Harbor Freight Predator 670 V-Twin Horsepower tests

    Or, use the three holes on the steel fan washer to mark your puller plate...
  2. Lucky Dog

    Formula-I?

    .
  3. Lucky Dog

    Formula-I?

    With great respect to the efforts of all on these threads, the more I see black and whites of 1947 aircraft and and plans from Mechanic's Illustrated for a proposed Formula Industrial racing class, the more depressed I become that this project will never fly. (Except, I want a Baby Bullet) The...
  4. Lucky Dog

    Video series on TIG welding thin wall aircraft tubing

    I've watched Scrappy's videos and can vouch for all of his information and techniques. Best I've seen for homebuilders.
  5. Lucky Dog

    Harbor Freight Predator 670 V-Twin Horsepower tests

    NO... the dead side compression will sap a lot of power, but you can ground one coil and taxi around to assess the possibility.
  6. Lucky Dog

    Formula-I?

    Yes, thanks
  7. Lucky Dog

    Formula-I?

    Fixed, thanks
  8. Lucky Dog

    Formula-I?

    Here are a couple of screen shots of a flying Hummel, powered by a stage-one modified 670cc Predator v twin. The URL is included in the screen grab so you can watch the video on FB if you want. The engine has a redrive (1.8:1, I believe) and probably a very efficient three blade e-prop, which...
  9. Lucky Dog

    Formula-I?

    dead link
  10. Lucky Dog

    Formula-I?

    Check out the Riblett GA 30-6012 airfoil
  11. Lucky Dog

    Harbor Freight Predator 670 V-Twin Horsepower tests

    3600 rpm, when there is a load. This is not to ensure reliability. 3600 rpm ensures 60 cycle electric output for generators, so it is the industrial standard for governed engines of all displacements. At or above 5000 rpm is where the stock rods become a liability and also, the cast iron...
  12. Lucky Dog

    Formula-I?

    I suggest we take a deep breath and consider the most likely customer/competitor who will be attracted to FI. If we accept that most will be homebuilders, then the sport will require a three year maturation period while the participants settle on various materials and aircraft configurations...
  13. Lucky Dog

    Harbor Freight Predator 670 V-Twin Horsepower tests

    TIG welding nubs onto the intakes and machining the injector ports may be a worthy shortcut.
  14. Lucky Dog

    Formula-I?

    A redrive would fit all of the industrial engines mentioned here and, once vetted for durability, would be reliable and safe for all models. Direct drive options would be a guessing game until each engine and prop arrangement was vetted in competition by the individual designers. My vote is...
  15. Lucky Dog

    Formula-I?

    Not with a fixed pitch propeller. One degree in pitch, one inch change in blade length can murder the thrust of these engines. Without a constant speed or in flight adjust prop, we would need a dry lake runway to get a 200 mph 40 hp aircraft to clear powerlines with a fix pitch. For a reality...
  16. Lucky Dog

    Current redrive options for Predator 670 project?

    What he said!
  17. Lucky Dog

    Drilling metal tube

    Now that you have stalled at the half way point, finish the hole with a 1/4 inch coarse round file. It will save you the time and material. Next time, drill a 1/4 inch pilot hole and then use a 3/4 inch metal cutting hole saw with the center drill reversed, so it acts like a bare centering...
  18. Lucky Dog

    Formula-I?

    Oval track racing at the proposed speeds will be neither challenging nor visually stimulating. Also, the oval format evolves into an ultimate speed equation that puts a premium upon high priced, fractional performance gains. I propose a pylon course based upon a wide, left turn oval, with three...
  19. Lucky Dog

    Formula-I?

    The 35 hp B&S 627cc with the 1.8 : 1 reduction puts out 225 lbs thrust at 4500 rpm with a 62 inch two blade prop.
  20. Lucky Dog

    Formula-I?

    All true if the engines are run direct drive at those propeller rpms. The path to extra HP is more pops per minute, Yes, peak torque falls off gradually as rpm increases past 3000 RPM, but that is only an issue for direct drive engines. The key to small engines is to increase RPM to some...
Back
Top