JFS 100 turbine

[ozrocketman]

Looking for a JFS100 engine, if anyone has one for sale or knows of one please pm me.

[pitciblackscotland]

Don't want to get your hopes up here mate but finding a JFS is going to be very hard to find, and why do you want a JFS? they are old turbines now if you do find one the will be clap out maybe good for parts only. Why not buy one of the new large RC turbines some are putting out 40kg of thrust or build one like some of the members on here have done.

Mark.

[ozrocketman]

Thanks Mark,

I do have several of the 40 kg engines but was looking something a bit more robust and with a longer time than the 25hr between maintenance on the RC type.

[pitciblackscotland]

OH!! OK I have sent you a PM.

Cheers,
Mark.

[Deleted]

The JFS100 doesn't use labyrinth seals in the gas producer. Instead, it uses a carbon disk ring seal that presses on a seal plate. The parasitic drag caused by this seal is tremendous and is also a very life limited component. I highly recommend a TS21 or the Rotax/Lucas series APU for a continuous twin shaft application.

[jetric]

Dec 10, 2021 1:28:50 GMT -5 @n1 said:

The JFS100 doesn't use labyrinth seals in the gas producer. Instead, it uses a carbon disk ring seal that presses on a seal plate. The parasitic drag caused by this seal is tremendous and is also a very life limited component. I highly recommend a TS21 or the Rotax/Lucas series APU for a continuous twin shaft application.

Hi,
The Rotax CT2023 and Lucas CR201 both have carbon seals on the compressor end of there shafts although these are not as large or heavily loaded as the JFS100 carbon seals so should last longer but they still do wear out eventually.
I have got two JFS100s and when I bought my first one 12 years ago I thought it was knackered when I turned the compressor shaft and it was stiff to rotate due to the drag from these carbon seals.
Another good contender is the Plessey Dynamics Solent if you can convert the oil system for continuous use, these engines use labarynth seals but the oil system is a one shot system. The Solent engine can be easily converted to a thrust engine aswell.

Richard S.

[Deleted]

I agree Richard,

It's impressive how free the Rotax engine rotates comparatively. The MK101 Solent is a interesting choice. I'm in the process of converting one to continuous which has not been as straight forward as I hoped. There's no oil jets in the engine other than the bevel gearbox and the scavenge ports are extremely small. The free turbine also has to maintain a circulated sump level for splash lubrication. It's going to work, I'm just curious if it will actually last a decent amount of hours without oil jets in the critical areas.

[jetric]

I have six plessey solents and I plan on converting these to continuous running sometime in the future when I get time, I also have one of the extremely rare solents that was converted by plessey for continuous running and the interesting thing is they still use the original drain ports but they are all connected to there own scavenge pump as there is a engine driven gear pump pack that sits next to the fuel pump.
The other issue with the solent is the fuel nozzles are staged to open in opposing pairs as the engine rpm increases to full chat but if you wanted to have the engine throttlable you need all the nozzles to be open so as not to create uneven temperatures and hot spots through the NGVs and turbine.
It's quite interesting to see the similarities between the plessey solent and the microturbo saphir, I wonder who copied who?
The easiest engine to convert to pure thrust and that has a decent amount of power is the Rover 2S 10501 Nimrod aircraft apu. Once the freepower turbine and NGVs are removed and a thrust nozzle fitted these can easily make 130~140lbs thrust all day long, this engine is what the Lucas and Rotax APU's where designed from.
Richard S.

Dec 10, 2021 8:04:21 GMT -5 @n1 said:

I agree Richard,

It's impressive how free the Rotax engine rotates comparatively. The MK101 Solent is a interesting choice. I'm in the process of converting one to continuous which has not been as straight forward as I hoped. There's no oil jets in the engine other than the bevel gearbox and the scavenge ports are extremely small. The free turbine also has to maintain a circulated sump level for splash lubrication. It's going to work, I'm just curious if it will actually last a decent amount of hours without oil jets in the critical areas.

[racket]

Have you looked at Horace's engines jetbeetle.com/JB_body_products.htm he's claiming 100+ hours of bearing life