Greeting from NZ I might add a few points There is also a return pulse where the exhaust pulse meets the atmosphere The pulse wave will go through the cylinder, transfer ports ,crank case,inlet when it is open and bounce off the inlet and also "turbo charge" the inlet "megafone will widen the rev range in which this occurs How wide is the power band I hope you put a patent on that design Good to see you have wood to survive Stamer's nut zero disaster that silver birch is good fire wood keep burning it keep warm
Thank you for your advise, it makes sense never thought of the pulse bouncing from atmosphere preasure, and it's the first time I've burnt birch, it dries well.
Very interesting. I'd like to model and tune this in a fluid dynamics simulation. It would be interesting to experiment with slightly different shapes. Maybe one day I will get time.
Very interesting content there, Sir. Besides installing an expansion chamber, are there any adjustments or modifications to the Carburater that need to be made? Thank you again for sharing this great information. Well done!
Hi, yes absolutely this expansion chamber won't do a lot on a standard saw as it needs to be capable of overcharging the combustion chamber so the muffler can send the waisted charge back into the combustion chamber.
Thank you so very much for sharing your knowledge and research with the expansion chambers. I'm playing with somewhat larger saws, 70+ and 100cc Husqvarna 3 series saws. My question is what percentage of the exhaust port are you masking with the freeway tube? Thank you again for your time.
Hi thank you for your kind interest, I would say I'm covering between a quarter and a third of the exhaust port, but you could use a bit less maybe as I've only built two pipes I doubt I've hit the sweet spot but it certainly works great.👍
Thank you Sir, you are definitely an undiscovered gem in the chainsaw world. I've very surprised you have less than 500 subscribers. Is there anything I can do to help get the word out about your channel? And do you have a public email that you're okay sharing with us? Have a wonderful day sir..
Hi Lutty, how are you managing to “shove” the charge back into the cylinder (thus supercharging the engine) with such a small length of pipe? I can see the concept however a true expansion chamber must be of a certain length in order to reflect the sonic pulse at the correct time
@@marklutwyche8578yes I understand the concept however it takes a certain time (physics) for the pulse to reflect , that’s why true expansion chambers are the length they are - the bleeder pipe seems like a workaround this - would you say your pipe delivers similar performance to a bona fide 20” long expansion chamber proper ? If so I am interested in obtaining one. I have built straight pipes using square tube approx the length of the stock muffler with a sonic plate on the end and 2 tube pipes on either side exiting about an inch before. They DO work and the torque gains are tremendous however they are loud enuff to wake the dead!
@fabzacres-blackcat yes the question about the distance is the key, on a saw we need a short chamber so the sonic wave is more constant and stronger and so would hold back the saw ,so that's where the freeway tube comes in to releive the preasure and shield a portion of the exhaust port to free up flow.
@fabzacres-blackcat I would say a proper expansion chamber of a known shape and size would be better, but if my pipes are developed and fee way pipe is ajusted to cover the port more or less also pipe size is tuned then I would say it could be as good, but it would be loads of work which I would not do I'm just having fun experimenting as a hobby.
Greeting from NZ I might add a few points
There is also a return pulse where the exhaust pulse meets the atmosphere
The pulse wave will go through the cylinder, transfer ports ,crank case,inlet when it is open and bounce off the inlet and also "turbo charge" the inlet "megafone will widen the rev range in which this occurs
How wide is the power band
I hope you put a patent on that design
Good to see you have wood to survive Stamer's nut zero disaster that silver birch is good fire wood keep burning it keep warm
Thank you for your advise, it makes sense never thought of the pulse bouncing from atmosphere preasure, and it's the first time I've burnt birch, it dries well.
Oh also there's a face book group I started lutys chainsaw mods and on there is the last dyno run I did with this pipe you might like to see.
Very interesting. I'd like to model and tune this in a fluid dynamics simulation. It would be interesting to experiment with slightly different shapes. Maybe one day I will get time.
Very interesting content there, Sir. Besides installing an expansion chamber, are there any adjustments or modifications to the Carburater that need to be made? Thank you again for sharing this great information. Well done!
Hi, yes absolutely this expansion chamber won't do a lot on a standard saw as it needs to be capable of overcharging the combustion chamber so the muffler can send the waisted charge back into the combustion chamber.
Thank you so very much for sharing your knowledge and research with the expansion chambers. I'm playing with somewhat larger saws, 70+ and 100cc Husqvarna 3 series saws. My question is what percentage of the exhaust port are you masking with the freeway tube? Thank you again for your time.
Hi thank you for your kind interest, I would say I'm covering between a quarter and a third of the exhaust port, but you could use a bit less maybe as I've only built two pipes I doubt I've hit the sweet spot but it certainly works great.👍
Thank you Sir, you are definitely an undiscovered gem in the chainsaw world. I've very surprised you have less than 500 subscribers. Is there anything I can do to help get the word out about your channel?
And do you have a public email that you're okay sharing with us?
Have a wonderful day sir..
@davesherron5665 thank you, please just share and subscribe 🙏
Great ideas and great work and great advice on the Stihl or any saws, thanks mate 😊
Hi Lutty, how are you managing to “shove” the charge back into the cylinder (thus supercharging the engine) with such a small length of pipe? I can see the concept however a true expansion chamber must be of a certain length in order to reflect the sonic pulse at the correct time
Hi, the sonic cone provides a sound wave and projects sound preasure towards the exhaust port, much like the procusionpreasure from a firework.
@@marklutwyche8578yes I understand the concept however it takes a certain time (physics) for the pulse to reflect , that’s why true expansion chambers are the length they are - the bleeder pipe seems like a workaround this - would you say your pipe delivers similar performance to a bona fide 20” long expansion chamber proper ? If so I am interested in obtaining one. I have built straight pipes using square tube approx the length of the stock muffler with a sonic plate on the end and 2 tube pipes on either side exiting about an inch before. They DO work and the torque gains are tremendous however they are loud enuff to wake the dead!
@fabzacres-blackcat yes the question about the distance is the key, on a saw we need a short chamber so the sonic wave is more constant and stronger and so would hold back the saw ,so that's where the freeway tube comes in to releive the preasure and shield a portion of the exhaust port to free up flow.
@@marklutwyche8578 you may have found the rainbows 🌈 end here Lutty!
@fabzacres-blackcat I would say a proper expansion chamber of a known shape and size would be better, but if my pipes are developed and fee way pipe is ajusted to cover the port more or less also pipe size is tuned then I would say it could be as good, but it would be loads of work which I would not do I'm just having fun experimenting as a hobby.
Lot of info here, what dyno are you running!?
It's a home made dyno, I've done a few videos on it on my RUclips channel.
@ I gotta check em out !