4 ms·

>all they need electricity for is the engine starter and, depending on age, the cooling fan. If you get an old enough diesel engine or can do the mod yourself

>all they need electricity for is the engine starter and, depending on age, the cooling fan. If you get an old enough diesel engine or can do the mod yourself you don't even need an electric starter. The first diesel engine I worked on used a gasoline engine as a "pony motor" to spin the diesel engine flywheel enough to generate the compression needed to start the diesel engine. From memory (probably wrong haha) you cranked the gasoline engine and brought it up to high rpm and then you started the diesel engine using a lever that gradually engaged the diesel engine flywheel bringing it up to operating speed. Once the diesel engine was running you backed off the lever and killed the gasoline engine. An obvious disadvantage would be the necessity to maintain stocks of two fuel types. Other than that it is a near fool-proof way to handle cranking a diesel engine. The electric starter is replaced by the gasoline engine and flywheel linkage. You effectively roll-start the diesel using the gasoline engine.

jaggederest 3y ago
Video of this in action: https://youtu.be/AL0ls_UpT8w?t=361 https://youtu.be/AL0ls_UpT8w?t=361 The whole video is worth a watch, but I linked directly to the timestamp where he begins to explain how the engines are started with a petrol starter. To power a foghorn. Amazing stuff.
- doodlebugging 3y ago
  Yeah that is amazing and it is just like the engines we had on those post-WWII bulldozers and maintainers. Fire up the gasoline engine and get it screaming at high rpm and then use that high rpm to transfer power to the flywheel of the diesel engine which will crank and run once the compression is high enough to ignite the diesel. Here is a video of a guy cranking a Caterpillar D2 like we had to crank our D4 back in the day. [0] When I started working with that small family-owned company I had no real experience with mechanical things other than my own pickup truck. When I finally moved on from them a couple years later I could maintain, tear down, and rebuild gasoline and diesel engines, compressors, hydraulics, air brakes, etc. We did all of that ourselves in addition to the real jobs of pipeline maintenance and repair and oil spill cleanup. I don't remember all the times I spent laying on the dirt floor of the "shop" there in central Texas and cursing all the oily sand and crap that fell in our eyes and faces as we tried to fix things after the day's work was done. Luckily beer-thirty was a cherished event that came with hang-down (summer sausage), cheddar cheese chunks, fresh onion slices, cold milk and saltine crackers. We finished most days in the domino shack trying to avenge the previous days' losses. Good times indeed. [0]https://www.youtube.com/watch?v=Ck210eL9qcI https://www.youtube.com/watch?v=Ck210eL9qcI
ComputerGuru 3y ago
> An obvious disadvantage would be the necessity to maintain stocks of two fuel types. Wouldn’t a starter motor running off a battery charged by the very generator you are running just be an all around better solution? You can run some modern starter motors off a tiny 12x8 in AGM.
- doodlebugging 3y ago
  That may be true if you are building this today. There evidently were enough problems with that setup back when these pony motors were common to make the use of a pony motor instead of battery power more practical. Perhaps it was a battery efficiency issue or one where a battery couldn't supply enough amperage to generate the torque required for a standard starter to cause the diesel engine to start and run. I know that a pony motor starter was standard on old heavy equipment diesel engines until the late 1940's and possibly after that.
  - ComputerGuru 3y ago
    That’s true and there certainly other considerations. I know which I’d consider to be a more solid/reliable option if I were going to be somewhere without access to electricity, at least. It’s easy to see when you’re running low on gasoline and when you’ll need to top off, but I wouldn’t want to be relying on a small 12v battery if I didn’t have a backup jump source available.
    - doodlebugging 3y ago
      That's true. For backup power on my own property I bought a used towable light tower/generator with an industrial Caterpilalr diesel engine and a 20 kW generator. It is portable, comes with its own lights, has a large capacity fuel tank so it can run for days, and it generates enough power to power my house and my shop should I lose grid power. Since it is portable I don't need to rebuild my old gasoline welder to use working on my fence since I can power my electric welder directly from the unit. It also has enough outlets to run several electric tools simultaneously. I have to add a frequency meter on the generator so that I can make sure I get some clean power and a power conditioner to smooth all the wrinkles so my electronics inside the house won't be damaged. Then I need to have an electrician add the subpanel and manual or automatic power transfer switch but for the price I paid it is a bargain over the usual generator packages available.

jaggederest 3y ago

Video of this in action: https://youtu.be/AL0ls_UpT8w?t=361 https://youtu.be/AL0ls_UpT8w?t=361 The whole video is worth a watch, but I linked directly to the timestamp where he begins to explain how the engines are started with a petrol starter. To power a foghorn. Amazing stuff.

doodlebugging 3y ago
Yeah that is amazing and it is just like the engines we had on those post-WWII bulldozers and maintainers. Fire up the gasoline engine and get it screaming at high rpm and then use that high rpm to transfer power to the flywheel of the diesel engine which will crank and run once the compression is high enough to ignite the diesel. Here is a video of a guy cranking a Caterpillar D2 like we had to crank our D4 back in the day. [0] When I started working with that small family-owned company I had no real experience with mechanical things other than my own pickup truck. When I finally moved on from them a couple years later I could maintain, tear down, and rebuild gasoline and diesel engines, compressors, hydraulics, air brakes, etc. We did all of that ourselves in addition to the real jobs of pipeline maintenance and repair and oil spill cleanup. I don't remember all the times I spent laying on the dirt floor of the "shop" there in central Texas and cursing all the oily sand and crap that fell in our eyes and faces as we tried to fix things after the day's work was done. Luckily beer-thirty was a cherished event that came with hang-down (summer sausage), cheddar cheese chunks, fresh onion slices, cold milk and saltine crackers. We finished most days in the domino shack trying to avenge the previous days' losses. Good times indeed. [0]https://www.youtube.com/watch?v=Ck210eL9qcI https://www.youtube.com/watch?v=Ck210eL9qcI

ComputerGuru 3y ago

> An obvious disadvantage would be the necessity to maintain stocks of two fuel types. Wouldn’t a starter motor running off a battery charged by the very generator you are running just be an all around better solution? You can run some modern starter motors off a tiny 12x8 in AGM.

doodlebugging 3y ago
That may be true if you are building this today. There evidently were enough problems with that setup back when these pony motors were common to make the use of a pony motor instead of battery power more practical. Perhaps it was a battery efficiency issue or one where a battery couldn't supply enough amperage to generate the torque required for a standard starter to cause the diesel engine to start and run. I know that a pony motor starter was standard on old heavy equipment diesel engines until the late 1940's and possibly after that.
- ComputerGuru 3y ago
  That’s true and there certainly other considerations. I know which I’d consider to be a more solid/reliable option if I were going to be somewhere without access to electricity, at least. It’s easy to see when you’re running low on gasoline and when you’ll need to top off, but I wouldn’t want to be relying on a small 12v battery if I didn’t have a backup jump source available.
  - doodlebugging 3y ago
    That's true. For backup power on my own property I bought a used towable light tower/generator with an industrial Caterpilalr diesel engine and a 20 kW generator. It is portable, comes with its own lights, has a large capacity fuel tank so it can run for days, and it generates enough power to power my house and my shop should I lose grid power. Since it is portable I don't need to rebuild my old gasoline welder to use working on my fence since I can power my electric welder directly from the unit. It also has enough outlets to run several electric tools simultaneously. I have to add a frequency meter on the generator so that I can make sure I get some clean power and a power conditioner to smooth all the wrinkles so my electronics inside the house won't be damaged. Then I need to have an electrician add the subpanel and manual or automatic power transfer switch but for the price I paid it is a bargain over the usual generator packages available.