Re:Engines for the Quickie

Someone found a solution to connect the prop in the Chinese V-Twin engine diesel?

Hi ! the VTwin diesel engine I got has a standard 1" key shaft , any hub for this kind of shaft would suit , in case it's not difficult to have one made from plans using CNC from aluminium.
At this moment I left this project aside , busy on another
but if you feel like having one done we can share the cost , making 2 copies would be cheaper at the end
here is shaft a1biofuel.net/Pics/25hpWin-Shaft.JPG

Lemans wrote:

During cruise with partial closed carburettor fuel burn can go up to 1liter/hp/hour on a 2-stroke engine.

I found this quite interesting...

I am not an engineer, but I have to admit a (an almost morbid?) fascination with the old military drone - the McCulloch 0-100 4318. I have several of them - and in fact i actually have one of the six-cylinder versions (not planning to use that on my Quickie - just to set everyone's minds at rest). But I HAVE considered the 4-cylinder 0-100...

Here's the "general status" the way I understand it (and trust me - digging out real world info on these McCulloch's is NOT easy). The bearing failures aren't an issue - updated bearings are available. These engines were last produced in 1988, but parts are still reasonably available. Rated at 72 hp at 5600 rpm. Designed as a tractor engine, so thrust bearings should NOT be an issue. The most widely used application has been in the gyrocopters - and some are still flying - but even on the gyro boards, more info is somewhat sparse...

These are two-stroke engines, though, and only weigh about 80 pounds (yup - great power to weight ratio). My thoughts were as follows...

1.) Is fuel injection an option? (and what would it take to BUILD such a system...?)
2.) Does ANYONE produce a tuned exhaust for these?
3.) Can they be run at lower rpm to effectively get into the 35 hp range? What kinds of problems do you run into trying to run a 2-stroke at lower RPM's?

If I do something like this, i think I'll pop for some dyno time and see if i can get some real world numbers on HP, torque, rpm, and fuel burn.

Skeet Wyman has apparently flown one very successfully on a Hummelbird.

One of the problems we face in the Quickie is a very small fuel tank - so fuel burn really IS an issue. Personally, I think I'd like to have about 35 hp up there - I fly out of CA, so density altitude CAN be a real issue (I remember trying to start my Twin Comanche late one July afternoon up near Winslow AZ - learned very quickly about leaning out for density altitude!!!) And I think 25 hp is on the lighter end of what i would consider acceptable.

The 1835 VW provides a lot of punch - I don't have all of the prior owner's data, but I remember some of the video he had taken, and I watched him fly it around the patch - plenty of climb, and plenty of speed! But that comes at a cost of weight and fuel burn.

We just don't have lots of options in the 35 hp range, do we?

(BTW - not recommending, endorsing, building, or even PLANNING to use one of these yet - just hanger flying here...)

Here is someone else running a Briggs and Straton on an airplane. I have searched a pretty good bit trying to find more information about Briggs on aircraft but haven't found much so far.

sdplanes.com/sd1buildersa.htm

and a video:

sdplanes.com/sd1video.htm

Hello Keuhjo,

I think I spend almost 6 months the last 2 years thinking about an engine for my future Q1 and I must admit that it??s a lot more complex to build a good small engine for an airplane than a big V8 for a racecar. Well, let??s try to answer your questions??

1.)Is fuel injection an option? (and what would it take to BUILD such a system...?)

2-stroke ore 4-stroke makes no difference in used fuel injection systems. These systems are on the market and are quit cheap, 200$ for a digital programmable unit

2.) Does ANYONE produce a tuned exhaust for these?

Yes, but as every modified engine needs a different calculated and tested exhaust,I expect it to be very expensive.

3.) Can they be run at lower rpm to effectively get into the 35 hp range? What kinds of problems do you run into trying to run a 2-stroke at lower RPM's?

Port timing on 2-strokes is provided by the form of the ports in the cylinders and the pistons.
So, it??s almost impossible to use a 2-stroke @ lower rpm??s without burning excessive fuel.It??s simply not build for it and you can??t change the timing with an other camshaft as in 4-stroke engines.

We just don't have lots of options in the 35 hp range, do we?

No, and that was the biggest surprise for me at the time I swapped from 4 wheels to 2 wings.

Regards Lemans

Ok - so next question then...

If the 2-stroke Mac really isn't a viable alternative (and it may not be for a VARIETY of reasons), then how much do those cylinders on the 1/2 VW really shroud the canard?

I'm certainly game to try and build a decent cowl out of fiberglass - but even if you can build a good cowl, does the whole effect on the canard negate any advantage in using this slightly higher horsepower engine?

I would so love to find a 2500 rpm 35 HP motor....

(ok - I guess that's redundant in this thread, huh?)