Potential firewall forward for high efficiency ultralight?

[boingk]

Hey guys, as a few might know I'm looking into making my own plane with a few basic criteria:

 

1. Carriage of a single person with minimal luggage
    
    
   
2. Easily constructed in a garage by an amateur
    
    
   
3. Construction costs no more than $10k
    
    
   
4. Cruise of at least 70kt
    
    
   
5. Fuel burn <10L/hr
    
    
   

 

 

This has led me to consider such designs as the Leeon Davis DA-11 and SD-1 Minisport, both high efficiency designs suitable to being powered with anything from a 20 to 40hp engine. Cruise figures vary from 80kt to 110kt TAS and fuel burn from 5L/hr to 10L/hr.

 

The current 'firewall forward' package I'm considering would be similar to this:

 

http://www.ebay.com.au/itm/221032070447?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

Its a derivative of the Briggs & Stratton 18hp Vanguard industrial engine, with twin cylinders comprising a 680cc capcity and ~20hp output over a widish range (up to 3600rpm). Removal of fan cooling would significantly reduce the weight of the engine, as would other modifications such as exhaust tract. They may also increase performance marginally (parasitic action of fan).

 

Before I continue down this path, does anyone have any other kind of idea for this kind of motive power? Criteria are weight of less than 40kg all up for firewall forward, with cost under $2k and at least 20hp sustainable.

 

Cheers all - boingk

 

 

[Sapphire]

I guess you considered the Sapphire, boingk? Are you still going to do the Hummel Bird? Couldn't see much welding on it and you don't need years of experience to rivit.

 

 

[boingk]

I've considered a lot over the past few months, Sapphire!

 

The Sapph and Hummel have both been on my radar, as well as stuff like the SD-1 Minisport (a wooden DA-5 in reality) and DA-11.

 

In reality I've found it a much more viable option to simply buy a plane that somone else is selling. I would still like to build my own single-seater someday but for the moment I think I will stick with my newly-aquired Gardan Minicab :D

 

Cheers mate - Enoch

 

 

[Sapphire]

Good choice. If you build a plane you are lucky to get your construction cost back. No payment for time. Fix up some one elses "gotten tired of it" plane.