Gas vs Electric Engine: HP requirements

[Charles84]

Might want to get away for "tractor" specs and look at it in more of engineering concepts....

Hydraulics and Pneumatics

Dale

That's a great resource. Thanks for sharing. I've got it bookmarked.

I found this article very helpful to understanding the difference between Electric and Gas Engine Hp requirements. Horsepower of a different color | Hydraulics & Pneumatics

 

[Texasmark]

I agree with the 2:1 difference. Electric motors are torque built and run better than 85% efficiency. A cap start, cap run motor is built to start into a load, like for air compressors. For things with low starting torques, like a fan, a split phase, with out any phase shifting capacitors works.

Gas run more like 50 and the torque curve starts out at zero, peaking usually around half rated rpms then slops down at a rate dependent upon the engine design. Trying to start a gas into a load either requires an over do it on the engine, or a clutching device which slowly introduces the load to the engine....only exception was a '91 Ford 460 cu. in. V8 one ton with the OD 4 speed manual. The only manual tranny I ever drove that I could dump the clutch at idle and the truck would continue to run.

 

[Charles84]

Trying to start a gas into a load either requires an over do it on the engine, or a clutching device which slowly introduces the load to the engine.

I'm certainly leaning towards the 2:1 calculation for pump sizing. Using a 35 hp Briggs Vanguard on a Modified JD 420 should allow plenty of excess power.

Regarding starting a gas engine into a load. My assumption, and estimation is that there will be minimal load on the engine when starting. (2 Variable Piston Pumps on Crankshaft and 1 gear pump on a Flywheel stub shaft. No pulleys or belts).

 

[MossRoad]

As I mentioned before, my PowerTrac PT425 has one variable volume pump and 2 fixed displacement pumps directly coupled to the engine, a Kohler Command 25hp gas engine. It is noticeably harder to start the colder it gets. It came from the factory with 10W40 oil for hydraulic oil. It has slowly been diluted with Mobil1 5W40 over he past 18 years at each filter change.

 

[California]

.my PowerTrac PT425... came from the factory with 10W40 oil for hydraulic oil. It has slowly been diluted with Mobil1 5W40 over he past 18 years at each filter change.

A dealer of quality Yanmar imports swore ATF was better than any UTF or motor oil in his later-model Yanmars with Powershift. (Basically an A/T but driven direct from the clutch shaft, no torque converter). I wonder if ATF would give you better low temp performance.

 

[MossRoad]

I don't know. It's been working well for 18 years so I don't want to start experimenting now. It takes 10 gallons of fluid.