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Post by racket on May 30, 2018 17:51:33 GMT -5
Hi
Before going too far down the freepower road you'll need to establish just how much "energy" you have exiting the gas producer , thats is , mass flow, temperature and total gas pressure , its pointless considering the freepower build until you have that data ..................but in the mean time get the kart engine sold and start having a think about general layout for the gas producer positioning , oil/fuel tanks/pumps , batteries etc etc ....................and possibly whether or not you want to go with a simple "chain redux" and restricted power output or gearbox and full power potential ..............a lot will depend on the actual "energy" the gas producer is able to provide , and you'll only know that after getting it fired up as a pure jet and measuring the jetpipe energy parameters.
Cheers John
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Post by azwood on May 30, 2018 18:01:10 GMT -5
Yeah ill get it mounted in and running to test the thrust and see what it actually does antill now its been hard to move farward without something to mount it in Hi Before going too far down the freepower road you'll need to establish just how much "energy" you have exiting the gas producer , thats is , mass flow, temperature and total gas pressure , its pointless considering the freepower build until you have that data ..................but in the mean time get the kart engine sold and start having a think about general layout for the gas producer positioning , oil/fuel tanks/pumps , batteries etc etc ....................and possibly whether or not you want to go with a simple "chain redux" and restricted power output or gearbox and full power potential ..............a lot will depend on the actual "energy" the gas producer is able to provide , and you'll only know that after getting it fired up as a pure jet and measuring the jetpipe energy parameters. Cheers John
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Post by azwood on May 30, 2018 18:11:22 GMT -5
Before bolting the engine in the frame i need to work out if i can run it left to right rater than stright firstly it might fit better and the flow path to the power turbine could run straight than any throughs on this anyone
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Post by racket on May 30, 2018 20:40:11 GMT -5
This is where things get "awkward" , because you don't have any data for the energy level exiting the gas producer its hard to decide on what freepower you need , and its the positioning of the freepower which will heavily influence the positioning of the gas producer so that the interconnecting plumbing is as simple/efficient as possible . With my 2 shaft kart jetandturbineowners.proboards.com/thread/40/2-shaft-turbine-kart-build I built the freepower stage first using standard kart engine mountings for it to simplify construction , this then necessitated having the gas producer positioned where it was . As I already had extensive amounts of data for the TV84 gas producer having operated it as a pure jet as well as a gas producer in my freepowered bike , it wasn't a problem to do the freepower "design??" ....................the Cummins turbocharger turbine wheel I used for the freepower was grossly undersized flow wise for the TV84's exhaust gases , hence the need for the "dump" duct and jetnozzle to process ~40% of the TV84's gases , the other 60% went through the freepowerwheel. As I was using standard karting chain and sprockets , again to simplify the build , horsepower/rpm output needed to be restricted to what the karting chain could survive with , namely ~30 HP and a max of 20,000 rpm at the freepower shaft ( N2) .................with a gearbox the freepower could have been spun to >45,000 rpm , and because of the lower output shaft rpm a more robust chain could have been used to handle the extra horsepower . If you intend using an Allison C20 freepower wheel , they turn anticlockwise when looking from the discharge side of the wheel.. Your gas producer is capable of producing more power than karting chain can handle if all the gases are used , it'll depend on what you hope to achieve from your kart build as to how complex the freepower stage needs to be . Throw some thoughts at me, and I'll throw back my 2 cents worth :-) Cheers John
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Post by azwood on May 30, 2018 20:44:02 GMT -5
Yeah i want to use an Alison wheel but like how Johansson did his bike running straight threw the wheel This is where things get "awkward" , because you don't have any data for the energy level exiting the gas producer its hard to decide on what freepower you need , and its the positioning of the freepower which will heavily influence the positioning of the gas producer so that the interconnecting plumbing is as simple/efficient as possible . With my 2 shaft kart jetandturbineowners.proboards.com/thread/40/2-shaft-turbine-kart-build I built the freepower stage first using standard kart engine mountings for it to simplify construction , this then necessitated having the gas producer positioned where it was . As I already had extensive amounts of data for the TV84 gas producer having operated it as a pure jet as well as a gas producer in my freepowered bike , it wasn't a problem to do the freepower "design??" ....................the Cummins turbocharger turbine wheel I used for the freepower was grossly undersized flow wise for the TV84's exhaust gases , hence the need for the "dump" duct and jetnozzle to process ~40% of the TV84's gases , the other 60% went through the freepowerwheel. As I was using standard karting chain and sprockets , again to simplify the build , horsepower/rpm output needed to be restricted to what the karting chain could survive with , namely ~30 HP and a max of 20,000 rpm at the freepower shaft ( N2) .................with a gearbox the freepower could have been spun to >45,000 rpm , and because of the lower output shaft rpm a more robust chain could have been used to handle the extra horsepower . If you intend using an Allison C20 freepower wheel , they turn anticlockwise when looking from the discharge side of the wheel.. Your gas producer is capable of producing more power than karting chain can handle if all the gases are used , it'll depend on what you hope to achieve from your kart build as to how complex the freepower stage needs to be . Throw some thoughts at me, and I'll throw back my 2 cents worth :-) Cheers John
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Post by racket on May 31, 2018 1:28:19 GMT -5
OK , so potential for maybe say 75 HP with full gas flow and full potential rpm of the freepower.
What sort of chain/sprockets are you thinking of using , possible gearbox ,ratios, speeds , etc etc .
You should be able to produce ~80% potential HP at 50% freepower rpm , so say 60 HP at maybe 15,000 rpm ...........this is motorcycle territory , maybe use a small single cylinder bike engine ,and fit the freepower shaft in place of the crankshaft , use the gear primary redux , weld the clutch closed and simply drive in the gear that produces the desired top speed
Cheers John
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Post by azwood on May 31, 2018 1:36:16 GMT -5
OK , so potential for maybe say 75 HP with full gas flow and full potential rpm of the freepower. What sort of chain/sprockets are you thinking of using , possible gearbox ,ratios, speeds , etc etc . You should be able to produce ~80% potential HP at 50% freepower rpm , so say 60 HP at maybe 15,000 rpm ...........this is motorcycle territory , maybe use a small single cylinder bike engine ,and fit the freepower shaft in place of the crankshaft , use the gear primary redux , weld the clutch closed and simply drive in the gear that produces the desired top speed Cheers John I was thinking of useing a chain probley a 520 as far as a reduction i like the gearbox idear a harly gearbox would be good
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Post by azwood on May 31, 2018 1:40:17 GMT -5
On the outherhand what sort of potential does running a pure jet with an afterburner have for speed/acceleration just wondering
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Post by racket on May 31, 2018 1:59:03 GMT -5
Theres no comparison between thrust power and shaft horsepower , the shaft horsepower unit will accelerate much faster , pure thrust is really inefficient at our low vehicle speeds , it gets better as speeds increase , its a foot pounds per second thing , so at 550 ft/sec 1 pound of thrust is equal to one horsepower , but at 275 ft/sec its only worth half a HP, it gets really pathetic at low speeds
If you take your engine and afterburn it , install it in a kart , it might reach 120 kph in a quarter mile , but with the potential for 75 HP of shaft power it'd be closer to 200 kph .
I wouldn't go Harley , wrong sorta engine , you need a compact single cylinder, unit construction with gear primary drive, its the gears that allow high rpm of the turb shaft, chains are a low speed device .
Cheers John
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Post by azwood on May 31, 2018 2:03:57 GMT -5
Seems free power wheel is a no brainer.i just thought harly gearbox the old style were separated from the engine they were really small but a gearbox from a 2 stroke dirt bikes small too i get what your saying about the reduction on the crank gear Theres no comparison between thrust power and shaft horsepower , the shaft horsepower unit will accelerate much faster , pure thrust is really inefficient at our low vehicle speeds , it gets better as speeds increase , its a foot pounds per second thing , so at 550 ft/sec 1 pound of thrust is equal to one horsepower , but at 275 ft/sec its only worth half a HP, it gets really pathetic at low speeds If you take your engine and afterburn it , install it in a kart , it might reach 120 kph in a quarter mile , but with the potential for 75 HP of shaft power it'd be closer to 200 kph . I wouldn't go Harley , wrong sorta engine , you need a compact single cylinder, unit construction with gear primary drive, its the gears that allow high rpm of the turb shaft, chains are a low speed device . Cheers John
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Post by azwood on May 31, 2018 3:46:43 GMT -5
Anyway i pick the kart up tomorrow so things will go from thair
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Post by racket on May 31, 2018 4:08:23 GMT -5
Yep , it'll be much easier deciding on things once you have the kart at hand and can physically start positioning things , theres a fair bit more space in a kart than a bike for the installation , but it still gets a bit tight
Cheers John
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Post by azwood on May 31, 2018 4:12:38 GMT -5
Yep , it'll be much easier deciding on things once you have the kart at hand and can physically start positioning things , theres a fair bit more space in a kart than a bike for the installation , but it still gets a bit tight Cheers John Yeah its a better layout i don't mind extending the back if i need to because id love to take it to lake Gardiner and do some land speed raceing being longer would help
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Post by racket on May 31, 2018 4:53:39 GMT -5
A longer wheelbase on the kart would help with stability by allowing most of the weight to be between the wheels rather than overhung past the axle , with a very heavy engine at the back things can get twitchy
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Post by azwood on May 31, 2018 5:02:22 GMT -5
Whats the fastest you have gone in one of yours? A longer wheelbase on the kart would help with stability by allowing most of the weight to be between the wheels rather than overhung past the axle , with a very heavy engine at the back things can get twitchy
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