Gas Turbine : LUSENET : Scrapheap : One Thread

Why not challenge the srapheap teams to build a gas turbine engine? A simple gas turbine engine can be constructed from a complete automotive turbo charger with no precision engineering and the additon of a few "Junk Yard" items. See posting on CH4 site.



-- Ian F Bennett (, November 07, 2000


I like that Idea because the experts again would have to be used to make the engines

-- Gareth Hay (, November 08, 2000.

One problem with a subject like "gas turbine" is that there isn't much room for multiple aproaches. About the only one I can think of, would be solid vs liquid fuel. (wood or coal fired vs parrafin). Since its a lot easier to produce a solid fuel burner, it would be too one sided.

-- Jeff - Team "The NERDS" (, November 09, 2000.

Gas turbine engines can run of liquid, gaseous or solid fuel if it is burnt under special conditions. There would be many challenges in building one -

Combustion system e.g. air distribution what materials to use Type of fuel gas/liquid type of burner atomiser/ vapouriser

Starting system e.g. compressed air, direct motor conection, air blowers etc

Ignition system - blow lamps, spark generators back lighting/relighting etc

Lubrication of a turbocharger e.g. re using oil pumps pressurised oil tanks, oil recovery using other types of pumps, re using hydraulic pumps.

This is a great challenge and it can be done easily and at low cost!


-- Ian F Bennett (, November 09, 2000.

What application do you envisage the turbines being put to? In other words, in the last portion of the show, the test day, what will the teams be doing (that's exciting)?

best regards,

Dom McCarthy, researcher, Scrapheap Challenge.

-- Dom McCarthy (, November 10, 2000.

Putting a gas turbine to use is a perhaps tricky task, a homemade unit which runs is an achievment in its own right. A turbo charger based unit is unlikely to produce enough thrust to propell a vehicle unless it was very light e.g. bicycle (Has been done). A truck turbocharger might produce around 50 lBs of thrust. A GT could possibly be used to supply compressed air for some purpose, blow objects over or through another turbine provide mechanical effort.

Perhaps the two teams could simply be tasked with who can produce the most thrust as measured on a spring balance. Or with a lever arangement two engines could fight each other!

In believe that constructing a gas turbine is no more difficult than a steam engine and a more likely task with scrap yard components. I bet there are more turbo-chargers in scrap yards than there are steam engines!



-- Ian F Bennett (, November 10, 2000.

My brother and I built one about 18 tears ago when modelgas turbines were just being explored, we used a lorry turbo ,some stainless elbows and flanges possibly ex aircraft, a cenral heating oilburner nozzle and pump.We simply connected one end of the turbo to the other with a length of stainless pipe for the combustion chamber, the oilburner nozzle was fitted inside by brazing in a couple of flow deflectors and attaching it to them.To start it we used an old spindrier motor and held it against the front of the compressor nut with a bit of rubber tube between them, the pump was driven by a variable speed electric drill and ignition was by blowlamp.The whole thing was very bodged, but it did start and self sustain albiet only for short periods at a time.As it was a large lorry turbo it had ballraces and lubrication was just by filling the bearing housing with engine oil.The best effect we had was to kill the grass on our parents lawn due to the heat and oil fallout. It would be possible to add a second turbine to the exhaust and drive an alternator and see how many lamps could be lit by the completed turbines. Paul.

-- Paul Franklin (, November 12, 2000.

I'm a gas turbine engineer working at Pratt&Whitney here in Canada. Bare with me, while I put in a few of my random comments.

One problem with gas turbines is the speed at which they operate. The smaller the engine the faster they have to spin inorder to generate a reasonable amount of power. The engines I have experience with (0.5m dia., 1-2metre long, 1-8000lbt) run at 10,000 to 30,000RPM. Turbocharger based engines I've heard about run faster. This could make it difficult to attach loads to it, if that is the show's challenge. (On the other hand it could be a lot of fun (-: )

Also, the vast majority of the problems with modified turbocharger turbines have been starting. You have to get the airflow, pressure, temperature and mechanics just right to get them started. I'm not sure, but it may be a challenge for one day.

Some uses for gas turbines (besides airplanes) have been: - electrical power generation - locomotives and automobiles - ship powerplants - snow removal

All gas turbines are made up of 3 parts, compressor, combustor, and turbine, and there is nothing preventing each of these parts from being the basis for a very interesting show. The centrifugal compressor(pump) was used already in the fireboat show. How about a airegation(sp?) system, or a water wheel, or race for the hottest blast furnace, or giant vacumn cleaner ? "Think outside the box" as a good friend of mine keeps on reminding us.

Finally, this is by far the most enjoyable show on television. It reminds me of my days in University. I don't think I've ever been more proud to be a mechanical engineer than the day some of my collegues put a living tree, which was in front of the engineering building, through the middle of an intact car !

As for Cathy Rogers, thank you for looking so absolutely beautiful, and for showing us, by example, that engineering is not something abstract and difficult, but is simply everyday useful common sense.

Regards, QZ

-- Quan Zhang (, December 28, 2000.

Speaking as someone who has built a gas-turbine engine from a turbocharger, check out for details, I have to say that it's not that difficult to get something that works.

As others have pointed out, the problem might be finding a way to competitively test two teams.

A better idea (from a producer's perspective) might be to make the challenge just one of building "the most powerful jet engine" -- and this would also allow the inclusion of pulse-jets which are also very simple to build out of scrap - requiring little more than a selection of bits of pipe, some welding, drilling and an old spring-steel tape-measure or two for valves.

The challenge could see the two teams engines mounted on trolleys connected back-to-back by a wire and made to pull against each other for a full minute. This would allow all personnel to stay well clear of the running engines (for safety's sake) and also require that the engines be capable of running for more than just a few seconds in order to win.

Maybe the only remaining problem is that you can build one of these engines in well under 10 hours -- so there might need to be some other element introduced to complicate the matter.

-- Bruce Simpson (, December 30, 2000.

I'm still struggling with the problem of what task to put the jets to. It seems like such a waste of time to build a complete engine from scratch when there seems to be so many IC engines lying around for tractor pulls and races. Unlike myself, I just don't think viewers would be that much interested in the various ways of burning pressurized air and passing it through a nozzle.

-- Quan Zhang (, January 04, 2001.

To compare two homebuilt gas turbines a simple thrust measuring device could be constructed from a spring balance or weighing machine. The teams could be shown the thrust measuring equipment before they attempt to build their own turbines. Both teams could experiment with RPM, pressures and nozzle seizes to get the most thrust and compete against each other for maximum thrust however small or large this may be.

A turbo based gasturbine could be a genuine scrapheap product, there is potentialy an enourmous amount of excitement here, the spectical of a running engine makes great television which is what Scrapheap is really all about.

-- Ian Bennett (, January 04, 2001.

How about a gas turbine scrapheap challenge tug of war? The object would be to build a self propelling gas turbine on a trolley of some sort. Each teams turbo trolley would be hitched via a wire rope to the others. The whole lot could be put inside a test cell, or far enough away from anything to do any harm and remote control / monitoring arranged for each team. The winning team would be the one who dared to take the turbine up farthest / EGT highest / quickest etc, but it would be the best of 3 pulls.

Since even very small gas turbines make enormous amounts of noise, and they can explode extremely spectacularly, it would make brilliant TV.


-- Lisa Jane Kingscott (, January 23, 2001.

Two gas turbines could "Compete" for thrust if mounted at the ends of a pivoted arm, the arm would then move in the direction of the most thrust and could be brought up against stops or biased with a spring.

It may be difficult for two engines to pull against each other unless sepparated by some distance.

Of course individual thrust measurements could be made and simply compared afterwards.

I look forward to this exciting and genuine scrapheap challenge!

-- Ian F Bennett (, January 23, 2001.

why don't you have two turbine in a tug of war over a muddy area that blows it up if u lose

-- james (, February 20, 2001.

Even more fun would be to seed the yard with a couple of functional surplus jet or turboprop engines of about equal thrust, and have the teams build some kind of contraption that will effectively use the power of the engines. Don't laugh, it worked for steam engines, and would be WAY more exciting!

-- Waddy Thompson (, February 24, 2001.

Using real aircraft components would certainly be intersting and fun but does not fully enter into the spirit of the scapheap. Hi tech aerospace components are not common in scrapheaps. Turbochargers definitely are!

The real challenge is to get a homemade turbo based engine to run, this is entirely possible with scrap components, turbo-chargers are also much more common than steam engines!

Gas turbines produce much heat, smoke, flames and noise ideal for this form of television genure.

-- Ian Bennett (, February 25, 2001.

The gasses flowing from the exaust of the engines travel extremely fast, if an object "A Small Jar of Flower" was dropped into the stream it could be blasted into a target with great force.

The idea is to see who's engine can knock over the Santa Claus dummy in the most exciting fashion.

I was once talking to a man from the Air Force who told me that he and his Air Force buddies stood throwing fruit into the afterburner of an F111 while it was secured to the ground. He said that the fruit exploded as it approached the stream of super fast gasses. I laughed and thought "so thats what the Australian Air Force buget goes into".

-- Jordan Thomson (, March 05, 2001.

Using the jet eflux from a gas turbine to blow objects over might be the basis for a competition between two turbo-charger based engines. Objects could be placed at various distances from the exhaust nozzle, the furthest away to be blown over signifies the winning engine!

A fun and stimulating way to demonstrate the principals of a gas turbine engine.


-- Ian Bennett (, March 05, 2001.

Several amateur turbine builders have reported getting around 50lbs of thrust from their turbocharger-based engines built around large truck turbos and that's more than enough to propel a one-man vehicle.

Likewise, I've just finished building a pulsejet with 100lbs of thrust and afixing it to a simple gokart frame with very exciting results. I'm now building a valveless engine that has no moving parts and should produce around 70lbs of thrust.

All of these engines require nothing more than simple welding skills and an understanding of the theories involved (that's where the "expert" comes in).

Come on -- let's get a jet-engine tug-of-war tournament going!

Imagine the room for dramatic choreography :-) The pulsejet would likely have more thrust and win round one but then the turbine team could strike back by lighting up their afterburner in round two and scoring their own victory-- following which the pulsejet team could mount their thrust augmentor and leave it open for a nail-biting finish in the third round ;-)

-- Bruce Simpson (, March 18, 2001.

Dear Sir/Madam,

I am Master of Technology Student at Massey University New Zealand now doing research for thesis which is entitled “The Application of Cogeneration System to the cooling of food and Buildings in East Timor”, would like to know information about gas turbine which is operated with liquid fuel and can generate 1000 kWe. The waste heat can be used to drive absorption chiller to produce cooling capacity with capacity of 700 kW cooling. The information should include capacity, investment and installation costs, operating and maintenance costs. If machine guidelines are available, then I will be appreciate if you could send me one. If no gas turbine available in this range, then I will be happy if you can provide me information about the gas turbine which is operated in nearby of this range of electricity capacity.

Thank you very much your assistance and kindness.

Kind Regards,

Estanislau De Sousa Saldanha 2/45 Ada Street Palmerston North, New Zealand Phone: ++ 64-6-3573191 Email: or

-- estanislau de Sousa Saldanha (, April 20, 2001.

I agree with Bruce. Instead of just a gas turbine challenge how about a Jet engine challenge. It is possible to make a Pulse Jet (as in the V1 rocket bomb of WW2). This would give 2 approaches to the challenge. I would also provide a historical spin to the program explaining the development of the jet engine. As someone suggested previously the race could be a tug of war or tractor pull between the 2 types of engine (gas turbine V pulse jet). The race could be controlled from a safe distance. I would not like to be sat next the either type of engine in a vehicle.

Graham Wagstaff

-- Graham Wagstaff (, April 24, 2001.

I'm a third year mech eng' student,based in durban South africa.My passion for gas turbines and their immense dB levels and power, goes out even to simple engines using old truck turbos.I would love to see these machines on t.v, having build two turbojets from turbos, I have great respect for tur'blades spinnig at+-90K rpm. My only concern is that if an old turbo is actually in a scrapheap,it has long seen the day, and might cause injury if catasrophic failure occurs. So think hard! Turbines are alot different then pulsejets,and much more dangerous if you dont know what youre doing!!

-- alistair sharp (, September 18, 2001.

Many people have now built turbocharger-based turbines and, to the best of my knowledge, nobody has been injured as a direct result of one exploding.

If a "jet engine challenge" were to be run it would be a fairly simple matter to require that a safety shroud be placed around the engine in the same plane as the turbine and compressor wheels. This would simply be the same level of commonsense that sees most of the vehicles built in the show fitted with good strong roll-cages.

When you look at some previous challenges (particularly the one with the scrapyard hang-glider and canard glider), the prospect of a nice jet engine is almost a relief from a safety perspective ;-)

It's a shame the producers haven't followed up on this suggestion -- jet engines have all the things that "real men" look for in machinery:

- lots of noise - lots of power - lots of flame and heat - the potential for lots of speed

Oh yeah!

Come on guys -- let's have a jet-powered dragster competition!

Bruce Simpson

-- Bruce Simpson (, November 20, 2001.

keep watching...

-- dom mccarthy (, September 08, 2002.

What about ATR rocket engines (

or steam rockets

have anyone built these at home garage?


-- j6w (, October 01, 2002.

Does anyone out there know where I can buy 2nd hand gas turbines in the UK, I'm looking for a T62-T32 used in a USAF Airport genset?

-- Chris Rye (, January 10, 2003.

Just a though for you contest-minded folks who are suggesting a tug- of-war with jet engines: You don't have to separate them by a distance, to keep the two opposing blasts from interfering with each other. You connect the engines head to head so they are pushing each other instead of pulling. Duh! Then it's "push-war" instead of tug of war.

-- Dan Hartman (, February 12, 2003.

good idea

-- Tijmen de Haan (, February 03, 2004.

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