@@MichaelForrestChnl You really are appreciated, Michael! Your analyses, your explanations and your software taught me way more than all of the books I read and the experiments I made
I believe that’s why exhaust ports were widened with bridge ports and chamfering to allow exhaust pressure to reduce enough to open the transfer ports.
I have an oil question. I have an older twin cylinder 4 stroke model airplane engine. It is a glow fuel engine that has been converted to gasoline with spark ignition. Glow fuel is methanol with 18 to 20 % oil and 5 to 15% nitromthane to improve power and ease tuning. Crankcase lubrication is from blow by. Connecting rods are made of bronze and that is the bearing. 20:1 mix ratio was recommended but people had had failures, so now 15:1 is recommended. I was advised by someone with much experience to run 10:1. After reading your paper on 2T oils and watching videos I decided to try Honda HP2 at 10:1. It seemed to be too much and or too thick. There was a nice amount of oil coming out of the crankcase breather tube and I felt that lubrication was superior. More recently I tried Amsoil Dominator at 15:1. It ran much better but I felt like there should be more oil coming from the breather tube. Do you think I am better off with an oil like Dominator at 10:1 that seems to burn off, or a higher quality oil like HP2 or Belray H1R that is ester, but at 15:1?
I'm sorry but for head splitting questions I need some payment. That's work man. Actually you shouldn't ask me because I have no experience with engines like yours. All I can say is to look up the composition of Dominator on my oil page and then you'll probably scratch it off your list. www.dragonfly75.com/moto/oil.html
You are a smart Man Michael F. Thanks for the info. Well done.
Thank you kindly. It's nice to be appreciated.
@@MichaelForrestChnl You really are appreciated, Michael! Your analyses, your explanations and your software taught me way more than all of the books I read and the experiments I made
I'm pretty sure I remember learning a lot from your site like 8 years ago when I built a gas bike - it's cool to see you're making videos!
I believe that’s why exhaust ports were widened with bridge ports and chamfering to allow exhaust pressure to reduce enough to open the transfer ports.
yes, the wider exhaust ports make it more effective so they don't have to be as tall so the trapped engine volume is greater
I just updated the Porting Calculator to also show a rough calculation of horsepower as well as transfer capacity (delivery ratio).
I have an oil question. I have an older twin cylinder 4 stroke model airplane engine. It is a glow fuel engine that has been converted to gasoline with spark ignition. Glow fuel is methanol with 18 to 20 % oil and 5 to 15% nitromthane to improve power and ease tuning. Crankcase lubrication is from blow by. Connecting rods are made of bronze and that is the bearing. 20:1 mix ratio was recommended but people had had failures, so now 15:1 is recommended. I was advised by someone with much experience to run 10:1. After reading your paper on 2T oils and watching videos I decided to try Honda HP2 at 10:1. It seemed to be too much and or too thick. There was a nice amount of oil coming out of the crankcase breather tube and I felt that lubrication was superior.
More recently I tried Amsoil Dominator at 15:1. It ran much better but I felt like there should be more oil coming from the breather tube.
Do you think I am better off with an oil like Dominator at 10:1 that seems to burn off, or a higher quality oil like HP2 or Belray H1R that is ester, but at 15:1?
I'm sorry but for head splitting questions I need some payment. That's work man. Actually you shouldn't ask me because I have no experience with engines like yours. All I can say is to look up the composition of Dominator on my oil page and then you'll probably scratch it off your list. www.dragonfly75.com/moto/oil.html