[simpits-tech] Need a plan

[Matt Bailey]

On Thursday 27 January 2005 05:43, Bubba wrote:
> Bubba wrote:
> > Bubba wrote:
> >> It's been decided, I'm going to build an RV-4 :)
> >
> > Scratch that. RV-8 :) I'm 6'4" and 265#. The bigger cockpit would be
> > nice.
>
> Ok, scratch that again ;) I'm thinking KR2S with a 110 hp Corvair engine
> now.

	Idea: wait about 2 years after "deciding" on your plane before actually 
purchasing/building it. ;)

> I've been wanting to convert a car engine to spin a prop for years and
> the Corvair looks to be about perfect. The only 3 problems I see with
> converting car engines are the lack of thrust bearings (not that big of a
> problem, look at all the VW motors flying around), the power range being
> way wrong, and no way to use a hydraulic CS prop. Everyone tends to stick
> gearboxes on there to slow the prop down, but there's a better way. Just
> get a camshaft ground for the range needed. The prop thing isn't an issue
> anyway since I'll be using an electric prop anyway. Best part of the whole
> car engine thing is that you can buy an engine, rebuild it with the best
> parts there are, convert everything for use in the air, and still spend
> half of what a used Lycoming goes for.

	Hummmmm, I dunno. I've always had reservations about car engines in planes. I 
guess if you totally redid the engine and used high quality aviation stuff 
throughout, you might be ok, though I would expect potential problems like 
cracked cylinder heads or thrown pistons, valve troubles, etc to be a little 
more likely on such an engine (due to the probable case of it having lower 
quality alloys and less stringent manufacturing process control when made).

> I think I'll make a few test pieces
> to compare the weight and strength of the all wood fuselage construction on
> the plans (plywood over sticks) vs. my prefered wood stringers infilled
> with foam and glassed inside and out. Stick/foam/glass is WAY easier to
> build since you only need half as many vertical members (if that) and no
> gussets, but it is heavier. And I can still use the waterjet to cut stuff
> like all the 4130 fittings, the foam infill panels, firewall, panel frame
> and subpanels, etc. The thing is designed to be a 2 place, but
> realistically my fat backside makes it a single place with lots of room for
> camping gear ;) I'm going to see if it's feasible to set up the seat back
> with the ability to fold forward to make a big, flat area in the tail for a
> bed. The wing's too low to sleep under ;)

	I just looked it up.......cool looking plane! Only problem is it's a 
side-by-side seater, and too fat. :P The KR1 I see is a single seater, but it 
looks like a bad cartoon knockoff of the RV-3.

> Now to get that job, clean out the garage, order the plans, and start
> throwing cash at a hole in the air...
>
> First thing I'll build is from the firewall to the seat back using cheap
> materials (pine, cheap pink Home Depot foam, Bondo glass cloth, and cheap
> epoxy) to use both to get used to building HUGE model airplanes and to use
> as one helluva big joystick ;)

	Ah, a "functional" mock-up, good idea. :)

	-Matt Bailey