I have to say these L3s are very nice motors. Of the small initial batch that Piotr has produced every firing has been easily accomplished with the thrust quickly steading and no sign of burn through on the 15mm diameter motors.
I just took one out for an air test on a 290mm span Depron [ ] and balsa T33. Weighs in at 40gms and got a very nice flight out of it.
Jetmaster motor as quoted in January 1954 aeromodeller engine analysis supplement advises jet master thrust as 1.875 ozs .
Jetmaster with short augmenter tube rated at 2.5 ozs thrust
jetmaster with long augmenter tube rated at 2.25 ozs thrust .
believe that 1 once force = 0.2780 newtons force so lets say L3 average at 500 mN from the graph then 1.875 ozs thrust = 0.52127 newtons or 521mN
So these L3 are equal to a jet master without augmenter tube -- does this sound about right .. i hope so ????
Piotr is now producing L4 motors and these are very nice.
Weighing in at 28gms fully charged and in 18mm x 66mm tubes with an average thrust of 850mN (87gm or 3oz in old money) for 20 seconds. They follow the same general design as the smaller motors and ignite easily and fire smoothly. In fact with a slightly larger exhaust I was able to see some very pretty supersonic shock 'diamonds' in the exhaust.
(although this is not seen in my video, I need a better camera!)
I can see these being just the ticket for larger models and even, dare I say it, radio control.
These look very nice indeed - there are some classic large duration models, like the 'Vindsvreen Viper' which would go very well with this motor. Add (say) rudder and elevator, and you have a great model for some small field thermal soaring. Even I could be tempted!
Also, a tethered car:
Above: this early Wilmot Mansour car (1948) was originally (I think) Jetex 350 powered
or hydroplane :
Above: Jim Free (now sadly passed away) powered his Hydrojet with a Rapier L-3. How he would have loved the new TSP L-4!