3 ms·

3600rpm is pretty high. This thing must suck gas. You’d want to do some math to figure out if this approach was actually saving any money over a proper consumer

3600rpm is pretty high. This thing must suck gas. You’d want to do some math to figure out if this approach was actually saving any money over a proper consumer generator. Reliabilty would also be a concern. Not the engine itself, but the integration of parts by the user.

giantg2 3y ago
Depends on the situation. Very occasional use and already having the engine is probably fine. If you have to buy an engine, or use it often, then the math is more important.
stonedautist 3y ago
looking at the video and his responses to comments, buddy is a machine-recycling nut just using this to give himself a mobile welder on his acreage or whatever. he definitely knows it's a mad-max-by-way-of-something-awful "look what I made out of shit I had lying around" solution to a thoroughly solved problem. it's conceptually cool but it's a weird narrow use case and it's not an objectively good idea. you could address cooling by using a motor with a big clutch fan and a well-shrouded rad, and you would probably be better off using the engine's idle control system to manage this at lower RPM to save gas, but it'd still be lipstick on a pig and you could go to harbour freight and buy a prettier pig.
gambiting 3y ago
Why would the high RPM necessarily mean using a lot of fuel? I've had a little VW Polo 1.0L that used to sit at 4000rpm just to go 70mph on the motorway, and it still returned like 50 imperial mpg(~6L/100km).
- alistairSH 3y ago
  Most Toyota Siennas were delivered with a 3.5L V6. The earliest models had a 3.0L. And they usually have an idle RPM around 700-800rpm.
- rightbyte 3y ago
  Essentially you want the motor to makes as few turns as possible for the same power output. At some low rpm the burn cycle gets bad though. Depends on motor. Fuel effeniency charts need constant power lines to be useful or they fool people.

giantg2 3y ago

Depends on the situation. Very occasional use and already having the engine is probably fine. If you have to buy an engine, or use it often, then the math is more important.

stonedautist 3y ago

looking at the video and his responses to comments, buddy is a machine-recycling nut just using this to give himself a mobile welder on his acreage or whatever. he definitely knows it's a mad-max-by-way-of-something-awful "look what I made out of shit I had lying around" solution to a thoroughly solved problem. it's conceptually cool but it's a weird narrow use case and it's not an objectively good idea. you could address cooling by using a motor with a big clutch fan and a well-shrouded rad, and you would probably be better off using the engine's idle control system to manage this at lower RPM to save gas, but it'd still be lipstick on a pig and you could go to harbour freight and buy a prettier pig.

gambiting 3y ago

Why would the high RPM necessarily mean using a lot of fuel? I've had a little VW Polo 1.0L that used to sit at 4000rpm just to go 70mph on the motorway, and it still returned like 50 imperial mpg(~6L/100km).

alistairSH 3y ago
Most Toyota Siennas were delivered with a 3.5L V6. The earliest models had a 3.0L. And they usually have an idle RPM around 700-800rpm.
rightbyte 3y ago
Essentially you want the motor to makes as few turns as possible for the same power output. At some low rpm the burn cycle gets bad though. Depends on motor. Fuel effeniency charts need constant power lines to be useful or they fool people.