Wood and Chevys

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Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
I Joined the forum about a month or so ago, and someone suggested I start a new thread and introduce myself and share what I've been designing. Since I'm a spaz when it comes to online forums/discussion group websites, it took me a couple weeks to get around to figuring out how to start a new thread. Anyway...good to be here...Lots of good people and good stuff on here.
I've had it in my head for nearly 15 years to design and build a high performance airplane around originally the trusty ole chevy smallblock v8s...Now it's evolved to the state of the art LS series of (Corvette) chevrolet engines that I'm interested in. My airplane will be mostly spruce with birch & mahogany plywood. I'm just a wood guy...love the stuff....Love gluing things too...like my fingers for example...
Some of you have already seen a few renderings but here is the latest. Biggest change to the drawings are the radiators in the wing just like the DH Mosquito..After much reading and researching and looking at what others have done and experimented with, I just couldn't figure out a better way to incorporate the radiators. One thing I've learned quite some time ago is designing an airplane is a heck of a lot more work than flying one!
There is an album in my profile page with a few additional recent AutoCad renderings.
Feel free to question, poke fun, make suggestions, joke, ridicule. All welcome..Keeps me on my toes
4ft step ladder is for size comparison...to hard and time consuming to draw a 3d human in autocad:gig:
64.jpg
 

Autodidact

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Joined
Oct 21, 2009
Messages
4,513
Location
Oklahoma
Check out this website (if you haven't already), Mark-15 PSRU, by EPI Inc.. There's more to it than just a gearbox - such as the electronic engine control issue - but I really like those contra-rotating props and the redrive EPI is developing will be both handed rotation. He seems to know what he is talking about (as far as I can tell) and by the time you get the design work done, they might be ready, hope you have some disposable income! Being wood, your aircraft sort of reminds me of a twin engine Falco.

Here's a page with dimensioned drawings and a link to a 3d model download to help with design and lofting - sounds like he is getting closer to making these things available: Mark-15 PSRU Dimensions
 

highspeed

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Joined
Apr 10, 2011
Messages
275
Location
Spring, TX
I like it, especially the wood construction. The configuration looks pretty well thought out, what has your initial analysis shown? One question stands out in my head: Have you given thought to fuel tanks? Those V-8's are going to suck down the petrol at takeoff power, and cruise fuel consumption will be pretty awesome. Tip tanks?
 

Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
Well, as far as initial analysis, looks like it's going to be tough to keep the empty weight under 2200lbs. I've had a couple guys comment about center of gravity problems. I don't see a problem there in my preliminary calcs and eyeballing (and head scratching). There is plenty of room for fuel, I just haven't decided where to put it yet. I like the tip tank idea and this thing really looks wicked with the tip tanks on. I'll have to do a render of it with the tip tanks and belly tank installed so ya'll can see.....and actually the later LS series of Chevrolet v-8 are insanely fuel efficient considering the power available. The new Corvettes get 26mpg and go 0 to 60 in 2 seconds....it's ridiculous. But it's an EXPENSIVE engine. Really wouldn't be any worse than if I used a pair of 300hp IO 540's..Same goes for weight, A typical installed weight of a 300 hp Lycoming can go well over 600lbs..The Chevy LS 7 or newer LS9 can get under that even with radiators and all accessories. I like the LS9..it has a steel crank and titanium rods. And a pair of those with the geared drive would be just loafing along with 220knots showing on the ASI...That's the other thing that occured to me...this thing would cover so much ground in a given time I could probably get away with just 50 gallons of fuel per engine. The wings have enough volume that its just a matter of deciding how much fuel I want to carry. And honestly, I couldn't care less about ultra high cruise efficiency...It's a sport plane, so the wing planform is more like a competition aerobatic plane than anything else. It will also be as strong. I'm sizing the spar for 10g's..Well, actually, it's now more like 7g's with a 1.5 safety factor..I'm going to need someone smarter than me to help me with that area...hanging engines on the wing make it not so simple and I'm lazy when it comes to math. I can do it...just lazy...LOL...Fortunately I know several young smart structural engineers.
And thanks Marcel, ..yes I discovered those people and their drives are probably the best available (and most expensive)...there is also another very smart guy with a lot of racing and aviation experience that produces one that also looks very good. I'm not not worried about the money any more...that's what has stopped me before, and now that I'm 59, I realize that if I keep saying it's too expensive or to difficult, I will never do it. You only live once, and my time is growing short. I still have my health, and as far as money,.. like my best friend in San Antonio says..you cant take it with you. I think he's probably going to help out on money anyway.
Also, it looks like at 3000lbs, with this wing and some decent flaps and the power available, you could easily slow fly this thing at 55 knots..Sweet! You wouldn't want to do that down low for obvious reasons but, looks like it could do it. The point is, approach and landing speeds with be pretty low. But It's the minimum control speed with one feathered that will dictate approach speeds. Looking like wing loading will be 21-23 lbs per sq foot...compare that to a Cessna 310 (around 30lbs sq ft)
I'm tired of typing so thanks for the comments and keep it coming. All you guys are pretty smart and anything you say will get my attention...
thanks a lot!
 

Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
PS This is purely a sport plane, I did however, conceive of this with the idea that I could put 2 people with baggage, fishing poles, etc., and go somewhere very fast and still get into a relatively small medium altitude grass field. and maybe do a few aileron or barrel rolls along the way
 

bmcj

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HBA Supporter
Joined
Apr 10, 2007
Messages
13,300
Location
Fresno, California
Cool looking plane! I was trying to tell where they wing mounts relative to the fuselage. Is there a spar carry-through in the cabin?
 

Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
Spar is right behind the seats...and it's pretty massive, by the way. (about 13.5" deep by 6" wide presently) Behind the spar..or between main spar and aft spar is room for luggage area or aux fuel tank, camping gear, dogs cats etc....I thought about trying to put a third seat back there but gave up on the idea. Since its a mid wing design, the rear spar gets in the way and if I were to move the wing down and make it a low wing, it would just be a totally different airplane. You could mount a small seat for a child though, just the way it is
 

Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
Hey thanks!...I really like the mini Dyke Delta, despite my obsession with the ultimate personal twin ,I've also fooled around with designing a very small delta (or close to it), much like what your're doing....It looks very cool! And it looks like it would fly well!
 

deskpilot

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Joined
Jun 30, 2009
Messages
1,121
Location
Morphett Vale, South Australia. Just south of Adel
Hey thanks!...I really like the mini Dyke Delta, despite my obsession with the ultimate personal twin ,I've also fooled around with designing a very small delta (or close to it), much like what your're doing....It looks very cool! And it looks like it would fly well!
Especially with a lightened Rover V8 (all aluminium) up front. One day..............................maybe!
 

Dan Thomas

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Joined
Sep 17, 2008
Messages
5,230
It does look like it might have CG issues. Both engines and the cabin's occupants are ahead of the lift. Fuel behind the CG will cause a forward shift as it burns off.
 

topspeed100

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May 4, 2009
Messages
4,063
Location
Oulu/Finland
Dan's concern is worth to check.

I like wood too. I found yesterday the wing construction of the MC30....it has wood, foam and carbon...that's the way to do it !

I have my ancient v-8 racer enclosed below...with John Roncz's help...maybe a pretty fast too ? I would have intercooler behind the spar and inlet scoops on top of the engine aft...dotted line....outlets in the end of the scoops ( split vertically ) ! This was a secret until today.

Foil is very natural flow laminar of my own design ( with considerable lift at low Cd ).

May the force be with you and welcome !
 

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orion

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Mar 2, 2003
Messages
5,800
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Western Washington
It does look like it might have CG issues. Both engines and the cabin's occupants are ahead of the lift. Fuel behind the CG will cause a forward shift as it burns off.
I gave that advice in a previous thread and in more detail. Too bad he's going through all this work - it's a nice configuration but may be unworkable due to that and one or two other issues.
 

Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
"It does look like it might have CG issues. Both engines and the cabin's occupants are ahead of the lift. Fuel behind the CG will cause a forward shift as it burns off."
"I gave that advice in a previous thread and in more detail. Too bad he's going through all this work - it's a nice configuration but may be unworkable due to that and one or two other issues."

All airplanes and airplane designs have "issues"..Cessna 150's have issues...LOL...Goef Siers's all wood Barracuda has issues..A couple guys that have built them reported they were ending up with some severe tail heavy issues...Its a very straightforward but pretty short coupled airplane with a big heavy 540 Lycoming way out on the front end...and these guys were shocked when they realized how much extra length they going to have to add to the engine mount...I don't know what happened or what was going on,,maybe they used oak to build the tail...My point is, it's easy to look at something and thing Gee that's gotta be tail heavy or nose heavy or just plain heavy....or that just ain't gonna work...I do it myself occasionally....but there it sits and apparently it does in fact fly
Don't forget the famous DH Mosquito....Similar layout, similar proportions. One of THE best flying aircraft of that era

Most airplanes with the engine stuck out front will have the engine ahead of the "lift" so not sure what your getting at there ..but I'm easy to confuse...LOL....occupants will be sitting right in the middle of CG range so will have little to no effect on whether it's nose heavy or tail heavy. 2/3's or all the fuel will be carried ahead of the main spar, which in this airplane will put it all right in the 25-33% area of the average wing chord so not really a problem there either. If anything it will lean a bit towards the front of the CG range with the gear down....as My engineer buddy said..wait till it's all built and sitting on the gear before the engine mounts are built....positioning the engines will set the final CG point and I have a couple feet to play with there.

So no worries guys. CG issues aren't any better or worse than with any other airplane. I initially had my engineer buddy that I work with, help me get more accurate on weights, moment arms etc..I'm pretty good at that but he's REALLY good at it. I'm pretty much dead on as far as and weight estimates. If and when it gets built the airplane will be weighed just before the engine mounts are fabricated. I'm more concerned with where I will get the exta cash to start getting serious about actually building it..It's just to pretty not to proceed.
Ok, I'll shut up...I need more coffee
 

Wagy59

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Joined
Nov 25, 2011
Messages
270
Location
Farmers Branch, Texas
Hey topspeed, that racer is radical...I love it! It'll be nosehaeavy!!!...LOL..couldn't resist...I been hearing that a lot lately...
 

topspeed100

Banned
Joined
May 4, 2009
Messages
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Oulu/Finland
One little detail...it could be made to fire rearwards too..increasing the thrust by 110 lbs ( what a regular paraglider engine produces ) making the small nimble craft go supersonic ( hopefully if needed ) in a shallow dive.
 
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