BFTO
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Joined: February 2016
Posts: 128
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Post by BFTO on Oct 23, 2016 9:32:09 GMT -5
We are three friends who have just started building a turbo based jet engine on our free time. These are the components we have acquired so far: The engine is based on a "Holset H2D twin scroll" with the following measurements: Compressor: Inducer: ~65mm Exducer: ~92mm Turbine: Inducer: ~85mm Exducer: ~77mm The flame tube has a diameter of ~130mm with a total length of ~470mm, including the reducer. The three evaporation tubes have an inner diameter of 13 mm and a total length of 150 mm. Our plans are to build a control system based on a Arduino mega that regulates the fuel pumps with temperature-, oil pressure- and RPM- sensors. We are going to use diesel as our main fuel and propane as heating agent. When we get this setup to work we intend to add a AB. Our cancerns are: • How do we throttle the fuel pump (Bosch 044) in a easy/efficient way? • How should we design the failsafe control? Our plan is to set limiting values for temp, pressure and rpm to either kill the pumps or shut down the fuel flow with a valve. • What is the best/cheapest way to measure the RPM? Thanks to Anders and John for guidance.
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Post by Johansson on Oct 23, 2016 14:29:19 GMT -5
Great that you started a build thread, this build reminds me of my old jetcart which used a similar turbocharger. To throttle the 044 pump I´d use a simple PWM controller, you can find a 2kW controller on Ebay for just 10 euros. I use a Hobbs pressure switch as a safety cutoff for the fuel pump, I have connected it to the P2 gauge line and set it to 3 bar so in case I have a runaway the fuel is shut off when the boost gets too high. An exhaust temp shutoff might cause some trouble, especially while starting when the temps can climb very high for a few seconds. If the engine is built correctly the temps should stay in line as long as the revs are kept under control. My 5 cents at least. Cheers! /Anders
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mitch
Senior Member
Joined: August 2014
Posts: 285
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Post by mitch on Oct 24, 2016 12:35:35 GMT -5
As far as controlling fuel pump speed, as Anders said, you could use a pwm controller, or use the Arduino and a MOSFET to make your own higher power motor controller. I made one for my 12v oil pump. Or you could just use a simple switch and a bypass valve to mechanically control fuel pressure, which is a bit more simple and "safe" in my opinion. This looks like a cool build!
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BFTO
Veteran Member
Joined: February 2016
Posts: 128
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Post by BFTO on Nov 25, 2016 16:28:04 GMT -5
Thanks for the input, the engine is coming together slowly, but surley The propane injector and the diesel injectors will be finished next week, we will be looking into the plumbing and the electrical after that. Two things we know nothing about . Anyone have a schematic on optic RPM reader or tips on how we can make one? The next thing i need to draw up is the afterburner, I have drawn up the fuelring/flameholder. But where can i get some formulas to estimate the proper ID/Lengths/nozzle?. I have guessed 115mm dia, 65mm nozzle and total length of 800mm. Thanks to HydSupply Örnsköldsvik for the oil pump with internal pressure regulator, what a beauty
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Post by racket on Nov 25, 2016 18:18:52 GMT -5
Thats one very nice oilpump :-)
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Post by Johansson on Nov 26, 2016 2:43:18 GMT -5
A very nice transition for the pipe going into the combustor!
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BFTO
Veteran Member
Joined: February 2016
Posts: 128
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Post by BFTO on Feb 24, 2017 16:17:30 GMT -5
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Post by Johansson on Feb 28, 2017 17:13:30 GMT -5
Nice meeting you at Speed Weekend! My thoughts are in 100 places during those race weekends so I hope I didn´t look too distracted while chatting with you.
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BFTO
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Joined: February 2016
Posts: 128
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Post by BFTO on Mar 1, 2017 9:12:19 GMT -5
Nice meeting you at Speed Weekend! My thoughts are in 100 places during those race weekends so I hope I didn´t look too distracted while chatting with you. It was nice to talk to you! Got alot of footage of all the jet vehicles. I will look at the footage if something is worth upload. I miss gas turbines at the event, planning to change that in the future when I got more time and money. Need to get hold of a 553 or more powerful engine and build a car around it.
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Post by Johansson on Mar 2, 2017 2:38:29 GMT -5
That sounds like a fun project, I agree that there is waaaaay to few turboshaft vehicles at Speed Weekend.
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Post by Johansson on Mar 3, 2017 9:02:44 GMT -5
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BFTO
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Joined: February 2016
Posts: 128
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Post by BFTO on Mar 3, 2017 15:52:08 GMT -5
Yes, i was tempted to buy the car and motor last time it was out for sale. I have to wait some time before i buy engine/car. Im in the middle of kitchen/bathroom/laundary/Porch renovation and its not cheap
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Post by Johansson on Mar 3, 2017 16:41:39 GMT -5
Yes, i was tempted to buy the car and motor last time it was out for sale. I have to wait some time before i buy engine/car. Im in the middle of kitchen/bathroom/laundary/Porch renovation and its not cheap Ouch, doing those all those rooms at once get expensive really quick. If I were you I´d build a DIY turboshaft to race instead, much more rewarding and you can fix it when it breaks down. An old Boeing/Rolls Royce/whatever is just a pile of scrap if something breaks since you probably can´t afford having it repaired. A small wheel driven streamliner with a 90mm or so inducer turbocharger based turboshaft engine would be a really fast one, 100-ish HP and little air resistance would be fun for sure! Cheers! /Anders
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Post by racket on Mar 3, 2017 19:00:10 GMT -5
Hi Anders
My old TV84 based engine with its 89 mm inducer was good for 200 kph with me sitting upright and flapping in the breeze, with bits of bike hanging out everywhere .
Hi BFTO .............your current build with a suitable freepower would get you into the 60+ HP range which would get you to some decent speeds with a bit of streamlining
Cheers John
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BFTO
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Joined: February 2016
Posts: 128
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Post by BFTO on Mar 4, 2017 3:23:34 GMT -5
Yes, i was tempted to buy the car and motor last time it was out for sale. I have to wait some time before i buy engine/car. Im in the middle of kitchen/bathroom/laundary/Porch renovation and its not cheap Ouch, doing those all those rooms at once get expensive really quick. If I were you I´d build a DIY turboshaft to race instead, much more rewarding and you can fix it when it breaks down. An old Boeing/Rolls Royce/whatever is just a pile of scrap if something breaks since you probably can´t afford having it repaired. A small wheel driven streamliner with a 90mm or so inducer turbocharger based turboshaft engine would be a really fast one, 100-ish HP and little air resistance would be fun for sure! Cheers! /Anders I need a bigger gas producer for a power turbine in my opinion, not worth the time for that kind of numbers A couple of jets from last weekend.
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