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homemade jet

Posted: February 16th, 2012, 6:05 pm
by 2strokeforever
heres my 3rd and best running jet, made it in grade 10 summer holidays, figured the dimensions i wanted, cut out the steel, found someone to roll it, brought all the pieces to my uncles house and welded it up.......

then i set the turbo on a rock, with a cordless drill spinning a chevy oil pump which was sucking out of a 1qt oil bottle :rotfl:(i had about $7 into it at this point)

the look on my uncles face when it fired right up was priceless :lol:

the camera makes it sound quiet, but its loud, cant hear yourself yell loud
[youtube]http://www.youtube.com/watch?v=5PRgOxTj ... e=youtu.be [/youtube]

right now it runs off propane and makes 28 lbs thrust at 30 psi boost (guessing/hoping 160 000rpm) and will idle down to 1/2 a psi of boost. 30lbs isnt enough to power a go cart.... but if (when) i get it converted to shaft power that will be 25-30 horsepower at the wheels

heres my bigger jet, 55lbs thrust (60 000rpm ish) i start it with propane then run it off diesel, gas, used oil.... but since i was too broke to buy proper nozzles it ran kinda crappy, 10 second delayed throttle response :shock:
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right now the plan is to hook up the hot section of the big turbo (in the pictures) to the exhaust of the jet in the video..... that will be easy, the hard part will be converting 60 000rpm and 2.5 ft/lbs torque to 6000 rpm and 25 ft/lbs
(im pretty sure the aluminum compressor blades are the weak link and without them i can hit 80 000 rpm safely)

so if anyone knows where i could get a 1" gear and a 10 or 12" gear, or something close..... im looking, too bad i dont know anyone willing to lend me a milling machine for a day

Posted: February 17th, 2012, 10:21 am
by NightBiker07
Not sure I quite understand how this runs? I looked at a few builds of these, and dont quite understand it.

:cool:

Posted: February 17th, 2012, 7:59 pm
by 2strokeforever
imagine a turbo diesel engine running at heavy load.... all the turbo sees is fuel getting burnt in between the output of the compressor and input of the turbine
im just replacing the diesel engine with a tin can designed to shield the flame from getting blown out

Posted: February 18th, 2012, 12:23 am
by NightBiker07
Always thought Turbos used the exhaust gas pressure to spin the turbine, which spins the compressor to force air back into the motor?

Posted: February 18th, 2012, 7:58 pm
by 2strokeforever
yup thats exactly how they work...

Posted: February 18th, 2012, 8:15 pm
by NightBiker07
2strokeforever wrote:yup thats exactly how they work...
So...you make fire in a combustion chamber, pumping fuel and air in, the pressure created runs through the turbo?

Posted: February 18th, 2012, 8:43 pm
by 2strokeforever
turbo compressor pumps air into combustion chamber, then its burnt
the hot air goes thru the turbine, which powers the compressor

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the theory is real simple, getting one to run isnt that hard, getting one to run good with low EGT is real tricky
the lower your egt the smaller nozzle (more back pressure) you can run which makes more power

next i will be running a compound setup, and if i can get over 100lbs thrust with afterburning then ill keep it thrust powered, if not i will convert to shaft power

Posted: February 18th, 2012, 9:41 pm
by NightBiker07
Definitely has a Cool factor. But is there any real advantage here? seems like it would eat fuel?

Posted: February 19th, 2012, 7:13 pm
by 2strokeforever
But is there any real advantage here?
i guess you could say with a few tweaks you can run it on ANYTHING that burns, propane, diesel, strong whiskey, coal dust, and if you did a major overhaul you could run firewood, garbage...
one day i will make one that burns tires, my way of telling greenpeace what i think of them :lol:
seems like it would eat fuel?
ya, a propane tank with no regulators or restrictors cranked WFO will only rev it to max boost if its warm, on the little jet...

that same propane tank on the big jet will get it to 4lbs boost, then everything is hot enough to switch over to my used oil/diesel mix which is pumped by a ford diesel fuel pump (no restrictive nozzles), which barely gets it to full power


interesting fact, on the big jet the exhaust turbine extracts 135 horsepower to power the compressor, and theres still 60hp left at the nozzle

Posted: February 19th, 2012, 7:22 pm
by NightBiker07
2strokeforever wrote:

interesting fact, on the big jet the exhaust turbine extracts 135 horsepower to power the compressor, and theres still 60hp left at the nozzle
next challenge is getting it to the wheels. I imagine a responsive throttle is hard to get as well.

Posted: February 19th, 2012, 7:23 pm
by NightBiker07
Would make an awesome apocalypse generator though. run it on garbage/wood/etc....

Posted: February 20th, 2012, 9:25 am
by B440
NightBiker07 wrote:Would make an awesome apocalypse generator though. run it on garbage/wood/etc....
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Posted: February 20th, 2012, 8:29 pm
by 2strokeforever
next challenge is getting it to the wheels
got the turbine.... but 60 000 rpm transmissions arent easy to come by
im looking for a small set of spur gears aprox a 1 inch round and a 8-12" round both roughly 1/2 wide, will pay a fair price
I imagine a responsive throttle is hard to get as well
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not bad, from 5lbs boost i can get to wfo in 3-4 seconds
(at 1/2 a psi it takes 30 seconds), once i get a transmission i will have a "clutch" that dumps all the pressure before the turbine
and ill run it at or near wfo then use the "clutch" instead of the throttle