Two stroke engines in a racer ?

[First time Juke]

Re: Two stroke engines in a racer ?

I'll have some of what he's smokin' please!

Juke, I know its the middle of the long cold winter and your bored but give me a freakin' break. Your not going to build a plane with an empty weight of 150 lbs and a gross weight of over 300 thats going to carry anybody safely around anything at over 200 mph, with a model airplane engine of 10 hp, even on fuel and with a pipe!

I dunno what you referring at, but Cri Cri already weighs 145 lbs empty. This is smaller and Cri Cri flew 35 years ago..techniques have developed a lot since. I say at least 180 mph and take off from harvested field even.

[First time Juke]

Re: Two stroke engines in a racer ?

Juke,
If you have a motor that spins that fast, why have the added weight of a reduction gearbox, use one of those unducted/supersonic fan/prop. gizmos. They like to be spun fast. And it wouldnt be racing without alot of noise right?

http://en.wikipedia.org/wiki/Propfan

Something like this on the front end of my supposed design ?

I think I need that type of system if I wanna go 500 mph ?!

Noise is good in racer..but does 180 mph sound too slow.

[Bob]

Re: Two stroke engines in a racer ?

Something like this on the front end of my supposed design ?

I think I need that type of system if I wanna go 500 mph ?!

Noise is good in racer..but does 180 mph sound too slow.

It will work at slower speeds to, the prop dosnt care what the ias is, its just designed to spin alot faster than a regular prop. and its a small diameter so you even get less drag. You just need a motor that can spin it at the speeds they are desined at. There was a biplane at the races this year that was supposed to use one, with just two blades, unfortunatly he crashed and passed. The crash wasnt from the prop not working, his motor wasnt running properly.

[First time Juke]

Re: Two stroke engines in a racer ?

I think I just need 18/18 props instead of the 28/10 and some 12 000 rpm ( with tuned pipes and nitromethane ). When a plane is lot smaller than a BEDE-5 ( = almost same lenght and span with Cri Cri ) I need also a lot smaller props in a twinengine aircarft ( and lotsa balls to fly it ! ).

I dunno 18/18 prop looks ridiculously small...22/14 and 12 000 rpm would yield 160 mph ( VNE also ? )...that is not bad is it...looks convincing in a 3-view here on my other tube. Is it badly supersonic still on prop tips ?

I get 189 mph top speed with 22/16 at 12 500 mph and some 210 mph VNE. With VNE I am referring to a speed where the prop starts to works as a brake. I guess it is wise not to design a plane to faster than that !

If that is AOK then it is the goal ( Lamborghini top speed was the initial goal ).

[First time Juke]

Re: Two stroke engines in a racer ?

I know by experience that a prop turns approx. 10% faster in the air than on the ground so to reach 190-200 mph I need 20-30 hp / engine to turn these props.

[First time Juke]

Spooky !

..and now gets really spooky...10% to that 520 mph gives 572 mph !

Watch out Rare Bear ( please tell me what is wrong here ) ! It is the thrust 48 lbs per engine is not enuf..I'd need 120 lbs per engine at least right ?

I checked in the net that Honda RS 125 ccm output can be 62 hp....

....even 100 ccm engines can have 22 hp.

---------------------------

Chart 3 ( second ) clears the problem..212 lbs of thrust looks plausible right ? That 28 inch dia prop looks enermous in a plane this small.

[First time Juke]

Re: Two stroke engines in a racer ?

Here is the ARNOLD AR-5 record setter !

http://www.ar-5.com/

If I had 30 hp per engine ( and least 2 x 125 ccm engines or nitrous in 100 ccm) I think this kite if well built and aerodynamically refined/studied and most of all flown by excellent pilot could be pretty close.

AR-5 had 65 hp engine.

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Here is a chart ( 4 ) that explains what Tweedy could do with existing paraglider 100 ccm 22 hp engines with regular gas !

[Bob]

Re: Two stroke engines in a racer ?

Juke,
You need to find and buy this book.
Two Stroke Tuners Handbook by Gordon Jennings. Its the bible for two stroke engines, this guy is amazing. I met him way back when my brother was racing ow41 and ow42 yamahas. An amazing man.

[First time Juke]

Re: Two stroke engines in a racer ?

Juke,
You need to find and buy this book.
Two Stroke Tuners Handbook by Gordon Jennings. Its the bible for two stroke engines, this guy is amazing. I met him way back when my brother was racing ow41 and ow42 yamahas. An amazing man.

I believe you Bob.

I made a RACER version and specs for a SUPER TWEEDY !

1:1 power to weight ratio ( hp/kg ) should bring it to where no man has been before.

3 cylinder row or 4 cylinder boxer 2 strokes 250-300 ccm with tuned pipes should yield 110 hp each ( using methanol and nitro ) and 70 hp when using regular gas ( latter for a 2 seater aerobatic trainer ).

Bob, if you make the engines I will provide the planes..and let's make a factory to manufacture both.

rgds,

Juke

[First time Juke]

Re: Two stroke engines in a racer ?

the 300 ccm 4-cylinder boxer is already here;

http://forgues-research.com/page8.html

Here is the Tweedy speed chart for it too:

[Box A35]

Re: Two stroke engines in a racer ?

Just go big and get a couple of these 530+ hp snowmobile motors.

http://www.youtube.com/watch?v=qpoEjY7KDdo

[First time Juke]

Re: Two stroke engines in a racer ?

Just go big and get a couple of these 530+ hp snowmobile motors.


http://www.youtube.com/watch?v=qpoEjY7KDdo

In fact over the weekend I made small 3-d model of wood and I realized the plane is way to small ( I followed missleading data in wingarea ) and now the plane is circa 12 ft long and 14 ft span ( previous was 9 ft and 15 ft ) and in fact with a straight wing that engine might be doable with wingtanks ( as a P U S H E R ) !

I think there are too many hp:s...or we need a 5-6 blader prop ( to increase the thrust and making the prop smaller to avoid the supersonic propspeeds ). The PSI 995 ccm at 225 hp would go very fast too..with methanol and nitrous it could be doubled.

This new version gear arrangement will allow a pusherversion to be made..and these charts ( Case 1 and 2 ) refer to this very low drag coefficient pusher only. I think we only need a man like Eric Ahlstrom to work on this to make it real and someone to fund it !

If my mind doesn't play a trick on me I think I did solve the problem of the directional stability problem ( experienced by mr. Penney with Learfan 2000 ) with a new kinda fuselage ( and engine cooling airflow ) as well.

If I am not mistaken a direct drive from engine could be used on the prop via shaft.

See yourself data for the engine and props;

[First time Juke]

Re: Two stroke engines in a racer ?

This has been developed for UAV:s

http://www.evo-engines.com/products/results.php?family=12

50 hp at 15 kilos..and roughly 500 ccm.

New Tweedy could do 250 mph with those for certain.

[First time Juke]

Need for a cheap transport ?

Does it really exist ?!

I ask this because many people seem to take me as an idiot at least here in Finland about this 2-stroke thing.

Regular gas costs here 8 USD a gallon. Would you be concerned and seeking a really cheap way to go from point A to B at 250 mph at these gas prizes..I am a bit concerned that none here seems to be.

rgds,

Juke

[First time Juke]

THRUST HP values !

I just want with certain sadness inform you that this THRUST HP program that calculates speeds and horsepowers in this thread is inaccurate..it seems to be true in .15 - 0.3 size engines ( models ), but when I went and placed Dago Red prop into the program and wanted 517 mph it told that I need 27 440 horsepowers.

What it actually means is that TWEEDY can go lot faster with less hp:s as does Dago Red in reality !

so be informed,

rgds,

Juke