Snowmobile Project feel out (seeking info)

[jaw818]

Hello all, 

I have always been fascinated by turbojet engines, I have built one out of an automotive turbocharger, and have a number of idea I would love to pursue using them. However, unlike my normal gear-head projects, where 2-stroke and 4-stroke gas motors are abundant in every size shape, and application you can imagine, turbine engines are not exactly just laying around where the average person with an average billfold can pick one up and stuff it in what ever crazy idea he has been dreaming about.


So I live in MN, I have a fair amount of experience fabbing and working on different vehicles, but as stated before, very little experience hands on with turbine engines. 
Ive seen them stuffed in golf carts, boats, go-karts, etc... but what I really want to do is put one in a snowmobile. Not a thrust powered sled, but a turboshaft powered sled. 

For those of you unfamiliar with snowmobiles, they are generally a 2-stroke powered machine, anywhere from 250cc to 1200cc (averaging 440-600 most commonly). They average around 100 HP, weight between 400lbs and 800lbs w/o a rider. Their power band is generally betwenn 8k-12k RPMs, and they use a centrifugal clutching system that engages between 5-8k RPM and can be adjusted to engage at any RPM, with a belt to transfer power from motor to chain case, and the chain case drives the jack-shaft (drive shaft) that spins the track. Most modern snowmobiles are capable of 100+ MPH, and can near that speed in less than 1000 feet. 

So in the research I have done, I have found that many APU and Starter jet engines weight less than 100 lbs, produce around 100 HP, and turn massive RPMs that are generally reduced in gearbox to a PTO. The dimensions, weight, and power all seem to be prime for a snowmobile application. The centrifugal clutching system used is perfect to help overcome the torque issue by allowing the motor rev up, and Snowmobiles are designed to be operated at High RPM. So in my poorly educated understanding, it would seem that a snowmobile would be a great application for a Small turboshaft engine. 

So here is what i would love some help with

1st: Has anyone ever seen this done? I have looked all over the web with no success in finding a turboSHAFT powered sled. Just jet powered ones. 

2nd: what would be the best engine to use taking into consideration price, dimensions, power, reliability, etc. Where nd how would one be aquired. 

3rd: How difficult is it to convert the fueling system to run on pump gas, E85, Diesel #2 or #1, or any other common and easily attained fuel?

4th: what input, advice, precautions, limitations, etc could be said about trying to stuff a turboshaft motor in a snowmobile. 

Thanks in advance.

[Johansson]

Hi and welcome to the forum!

Here in Sweden someone fitted an Rolls Royce Allison C18 helicopter engine in a Yamaha V-Max chassis 10 or so years ago, they used a hydraulic drive and with the engine, drive and oil tank it must have been very heavy.

I did a quick search but couldn´t find anything about it on the web, perhaps you have better luck.

Cheers!
/Anders

[racket]

Hi

Theres no reason why you should have any problems fitting a turbine engine .

"Best engine" ...........well , whatever you can find at the price you want to pay , there isn't a lot of choice available .

"fueling system" ............no dramas changing to diesel or a diesel mix.

"advice, precautions" ..............LOL , that could take a lot of explanation , its doable , so get started :-)

Cheers
John

[gidge348]

Good project, I personally would look at an APU engine as opposed to a starter, starters tend to be lighter and more power per lb. of weight, but the down side is they are not designed for long term running so will usually need modification to the oil system/cooling and carful monitoring of the temps if you want to run them for more than a few minutes.

When looking try and find a free power turbine as opposed to single shaft engine. Turbines only produce good power over a very limited rev range so a free power turbine allows you to use power over a wide range of output speeds, also you can ditch the centrifugal clutch.

Apu's and starters are not generally throttle able so if you are good with electronics you may want to tackle a FADEC engine if not have a good look at the fuel system and how you can throttle it.

Once you have done that be sure to post your build on this forum, sound like fun... & lots of good smart people here

Cheers
Ian...

[jaw818]

All good info. I'd like to see that v-max. However a id imagine a hydro system would be heavy and not provide the rpms a snowmobile requires.

I had not considered that a starter motor would be undesirable for extended run times. Can you explain what a FADEC engine is and explain the free air system a little furthers? I'd assume is a turbine PTO seperate from the intake/exhaust turbine shaft, but I'm not certain.

There used to be a video of a blue 1970s golf cart a guy put a turbo shaft motor in. It looked really professional and he claimed it did 70mph. Also, the engine sat under the seat so the gold cart looked factory aside from an intake cowl on the drivers side. Wish I could find it again to see what kind of motor he used and how he addressed the throttle problem.

Still looking for more detailed info on specific engines. Everything online generally needs to be shipped, and descriptions are written for people who have intimate knowledge with these motors, which I do not.
So if I decide to take the risk and drop a few grand on an engine, I'd like to know which models I should be focusing on and what I should be looking for. Also what is the common prices for them.

Thanks for all the great info so far.

[pitciblackscotland]

G'day Jaw818,
I think i know which golf cart you mean that had a JFS 100 in it. Have a look at www.turbokart.com/home.htm he use a JFS for his go cart project work out really well, but as Ian said they need to be some modifications done on the engine. I had a chat to Dino from www.turbokart.com/home.htm and he got a hour run time from the JFS with no problems, but i am thinking the fuel tank will be empty in a short time so the engine would be shut down and refueled plus he was using air start aswell so the air tank would be good for so many starts. So really you could not run the engine for very long unless you had a large fuel tank on aboard. Have a look at my vid of the test i did on my JFS and you can see how much fuel it used in the kerosene bottle in the right hand corner of the vid that was a minute run time youtu.be/bi6FamS5aG8

Cheers,
Mark.

[jaw818]

Mark,

I not sure that is the same builder. I recall it being a different engine than the JFS 100, but I could be mistaken. It's been a year or 2 since I watched the video, but I do recall it being the most professional and functional repurposed turbine vehicle I've seen that doesn't fly.

As far as fuel consumption, I guess that was something I hadn't considered. I figured a turbine engine would be more efficient, considering there isn't all the dead strokes and barrage of moving parts that a piston engine needs to operate. My 600 triple arctic cat chugs down a liberal amount of fuel, giving me 10mpg on a good day of easy riding... 6-8 or less if you ask it for all 125hp. My 15 gallon tank gets me about 100-150 miles. So I guess a good question is how quickly a 100 hp turbine motor will suck down 10 or 15 gallons of diesel under load.

What about the solar turbines? They seem to be popular in golf carts.

[gidge348]

Hi Jaw818,

I think the kart you are describing is one that had a Plessey Solent starter from RR Spey engine. www.gasturbine.pwp.blueyonder.co.uk/solent.htm
jetenginetrader.co.uk/product-category/engines/plessey-solent-apu/.

Yep it was a really cool build, I was not aware as Mark said that Dino got 1 hour running out of his JFS 100 so maybe a starter would be fine.

A FADEC engine is one that uses electronics to control the engine speed based load temp and other parameters. Some really smart people on this forum (not me) have worked out to trick this system to act as a throttle. The other system uses a mechanical pumps and governors to control the speed.

The single shaft engine has the output shaft connected directly to the gas generator (jet engine part) the free power turbine has another turbine that sits in the "jet" air output and is "blown" by the hot air kind of like a torque convertor in an auto transmission. Watch a helicopter start and you hear the engine come up to idle and a little while later the blades come up to speed, that's a free power system.

Don't expect the engine to be cheaper on fuel than your 2 stroke these things DRINK fuel. The good point is that just about any liquid that will burn can be made to work in them.

If Racket (John) is listening here he may be able to calculate how much fuel a jfs/Solent would use per hour?

As for the Solar turbines, they make a lot of engine in a lot of sizes I have not seen any that very small (jfs/solent size) but that does not mean they are not out there. I am sure if you can find one anything can be made to work..... have fun

Cheers
Ian...

[racket]

Hi

A Solar T62 engine burns ~1 pound of fuel/ hp / hour at 150 hp , ~150 lbs of fuel at 150 hp or ~22 US GPH .

At say 50 hp it'll be ~1.5 pounds/hp/hr , at 100 HP its ~1.1 pounds/hp/hour so 110 lbs/hr ~16 US GPH

At idling conditions the burn rate is horrendous compared to even a 2 stroke IC engine , probably >4 GPH

Its basic thermodynamics , most small turbine engines use compression ratios of < 4 : 1 only half an IC engines , hence less energy extracted

Cheers
John

[gidge348]

Had a look at your question on fuel consumption.
www.avonaero.com/allied.htm
Usage 1.3 lb/shp(shaft horsepower)/hour
So 100 shp = 130 LBS/Hr
Jet Fuel SG ~ 8.34 lbs/gal
So 130/8.24 = 15.5 Gallons per hour usage..... not as bad as I thought? But I could have this all wrong.

Ian...

[jaw818]

All interesting. Fuel Econ isn't a huge concern. As long as 15 gallons can get me 20-30 miles I'd consider it viable.
I would imagine throttling could be tackled similar to a diesel, with an injection pump that delivers more fuel when more throttle is applied.

I like the free power idea. So this brings me back to my overarching question, which engines would work and where do I get one?

I think we have hashed out most things to convince me to start wasting money on an impractical vehicle that will make a good YouTube video (not that I needed much of a push to do that). Howeve I still am really at a loss for where to acquire an engine to fit the bill.
From what I've seen online I don't dare make a purchase. Some appear to only run on compressed air, others have no guarentee that they are even operational. Dies anyone have any insight or pointers on this?

[pitciblackscotland]

There are some turbines on ebay here are some to look at 141356376778 131411015796 281577975813 291362672227 This seller has some nice items for sale 301507800325. Was this the golf cart you were talking about? youtu.be/S_5x1IhN6CI

Cheers,
Mark.

[racket]

Hi

Your main problem with finding a suitable engine is your "limited" horsepower requirement , turbine engines are very expensive when new ,and it really doesn't make a lot of sense to make them in "small" sizes .

Most turbine engines in the ~100 hp range will probably be single shaft units made to drive a generator/pump of some sort at constant rpm , whereas a two shaft engine,with a freepower turbine wheel thats better suited for a "road vehicle ", aren't made in small sizes ................and is the reason why we make our own units .

Throttling isn't a problem , its simply a case of feeding more fuel into the engine , turbine engines are more like steam boilers than IC engines , theres an excess of air so all we need to do is add fuel even in the most rudimentary fashion and it'll work .

cheers
john

[jaw818]

Jan 28, 2015 23:06:20 GMT -5 pitciblackscotland said:

There are some turbines on ebay here are some to look at 141356376778 131411015796 281577975813 291362672227 This seller has some nice items for sale 301507800325. Was this the golf cart you were talking about? youtu.be/S_5x1IhN6CI

Cheers,
Mark.

YES!!! That's the one! I guess you were right, JFS 100, and it's been modified to have a PTO...  The description of what was done is far more detailed than the video I found a few years back. 

The ebay links you shared are not working on my device. 


Racket,
i had had considered building my own, but my shop is not a machine shop, I have a wire feed and stick welder, a torch, band saw and some cutting wheels, but no lathe or anything to extensive to allow me to make anything overly presice. 


The the automotive turbo that I turned into a jet  engine ran for about 10 minutes before the bearing melted down, though I expected that because there was a fair amount of shaft play before I started. I considered robbing some big old diesel turbos, doing a twin turbine unit, and trying to fabricate a system similar to the free power system for my PTO, but haven't been able to come up with a design that I know would work after putting that about of time and money into it.

[pitciblackscotland]

Mmmmm ok try this one stores.ebay.com/Avon-Aero-Supply-Inc Bruce at Avon-Aero-Supply-Inc has some nice Tiernay TT-40 gas turbine powered smoke generators for sale US $2,836.00 Here is Bruce email address

[e-mail]

Cheers,
Mark.