The previous page was getting a bit big so ive carried it onto this page.
---- April ----
Once i had it setup i turned on the gas and turned on the spark to see if it would ignite, it wouldnt. I realised that the spark plug couldnt get far enough into the chamber to ignite the fuel, so i got out the fill and opened up the opening so that the plug would fit. Once it was back in i tried to ignite it again but again nothing happened so i tried to blow a bit of air using the new leaf blower and this time it worked so i continued the air and reduced the fuel flow until it started to buzz.
With the increased air from the leaf blower it was definately much louder than before but still would not self sustain. At this point i noticed a few things about the operation of the pulse-jet as it was that made me think why it was nt working. This is what i think:-
- Air supply still not big enough, although the leaf blower has improved things the nozzle on it is rectangular where as my intake is circular so im going to make an adaptor that i can captor all the available air from the blower, as it is about half of the air goes down the side of the pulse-jet and is never used in the combustion.
- Fuel supply way to rich, im not sure if a pulse-jet can be supplied with too much fuel but looking up the tailpipe during operation i can still see a yellow flame burning continuously, there is a buzzing there but i think the continuous burning fuel may be what is stopping the engine from working properly. I think ill get a new regulator that lowers the pressure of the propane into the engine and should there fore stop the constant burning.
- One last thing i thought of was that the fuel wasnt being mixed properly, as im using direct injection the fuel and air are mixed inside the combustion chamber, the fuel enters from the middle of the valve retainer and i havent put any dispersal thing in to disperse the gas so as to get better mixing with the air. So im thinking of adding something to disperse the gas into the path of the air.
These are all possable things that could be wrong or i could be completely wrong and its something else but i will have to see.
i plan on adding the augmentor sometime soon even if the pulse-jet doesnt quite work yet.
The pulse-jet may not work as it is supposed to but if the conditions are right you can make it make one hell of a bang. I managed to do it on various occasions which the workers at the offices across the road found a bit worrying so the security guard came over but once he realised what it was he left.
To get the huge bangs i turned on the fuel and then turned it off then i turned on the ignitor and then the leaf blower just after and !!!!BOOM!!!!!! ive never heard anything like it form something so small. Although this isnt what the pulse-jet was designed for it was fun just seeing how loud we could get it. definatley worth a try!!
