Gas powered engine horsepower equivalent to electrical motor horsepower?

[KarenH]

Originally Posted by Al Skierkiewicz

Elgin,
...In the operation you are considering, gas power is easier to implement and that is why most designs use that type of engine.... All things considered, the gas powered approach is still the best over all design.

If you want to take an approach looking at the overall design, however, there are several other factors you should consider:

If you should ever want to take the machine on an airplane, let's say to go visit friends or to go to some kind of show or competition or something, no airline will ever let you take a gas-powered device with you. Even if you empty the fuel tank, the residual fuel and fumes represent a hazard that is completely unacceptable to the airlines and federal safety requirements.

On the other hand, if you're in a place with no electricity, you'd be unable to recharge.

Electric motors are usually much quieter than gas motors--a factor your neighbors will appreciate.

Transporting, storing and using gasoline has certain health and safety risks involving toxicity, flammability, and pollution (though if you already have small gas-powered devices such as a lawnmower, you've already taken that step). Of course, batteries have similar problems. Which set of risks would be of greater concern to you?

Gas engines are mechanically more complex than electric, and require more complex maintenance.

You also need to figure out how the control system will work with your setup.

In summary, there are the initial design considerations (What is the most feasible design for your needs?), but there are also the long-term usage considerations (which design will be the easiest to live with over the long haul?).

By the way, I've seen a guy zipping along the Strand in Manhattan Beach on a gas-powered SKATEBOARD. He has a hand-held control (probably the throttle) connected to the board by some type of cable. The little fuel tank is located behind the rear truck. I'm not sure such a device is legal on the Strand, though...

[greencactus3]

Originally Posted by KarenH

By the way, I've seen a guy zipping along the Strand in Manhattan Beach on a gas-powered SKATEBOARD. He has a hand-held control (probably the throttle) connected to the board by some type of cable. The little fuel tank is located behind the rear truck. I'm not sure such a device is legal on the Strand, though...

wow! didn't the kawabunga(spell check???) turtles have something like that? or was it wind powered... i kinda remember a huge fan on the back..... hehe.

[Al Skierkiewicz]

Originally Posted by KarenH

By the way, I've seen a guy zipping along the Strand in Manhattan Beach on a gas-powered SKATEBOARD. He has a hand-held control (probably the throttle) connected to the board by some type of cable. The little fuel tank is located behind the rear truck. I'm not sure such a device is legal on the Strand, though...

Gas powered skateboards go back into the sixties. You see them in several movies of the period. I think I remember one in "On Any Sunday" a doc with Steve McQueen. I have heard that many places outlawed them since they do not have deadman switches or brakes.

[aaronbr28040]

Talking about gas powered motors...I guess you will probably use a small Briggs and Stratton Engine. The horsepower ratings that you see are for the engine at 3600 RPM's. These motors will run, if in good shape with enough oil, at 3600 RPM constantly. By replacing the rod, using a shorter piston, twisting the cam, and using a 3HP flywheel and a few other assorted things you can get a 5HP Briggs motor to turn 9200 RPM running methyl alcohol racing fuel. These motors are what are run on the racing gokarts.
Anyways....thats for 4 cycle motors. You might consider using a 2 cycle weedeater motor. They can turn a lot of RPM's and I have seen small kids gokarts, minibikes etc powered by them. They are also really hard to blow as long as you keep oil in the gas. The connecting rod rides on the small crankshaft in these motors on bearings.
If you use a gas powered motor you will also need a centrifugal clutch of some type since you cant just turn it on and off like an elecdtrical motor.
-Aaron

[Matt Attallah]

Originally Posted by greencactus3

as long as you keep the block from overheating and have decent lubrication( i guess thats part of the overheating prevention) and dont run out of gas, quite a long time.... for example, car engine's peak output rpm is around 4000~6000 rpm. i think... not diesel, gasoline... and not rotary engines either, which tend to have lower rpm peak power. car engine's redlines are a bit higher than the peak, so well,,, im confusing myself again.... help?

Heh - now is when I inject my 2 cents worth...

A car engine's peak HP/Torque can happen low or high (depends on the application) For rock crawling and stuff that you need the most of the power lower in the band - you just change the timing/cam. I have seen engines with the most torque at about 2,000 RPMs. Now for horse power - yes you will typically need to go higher. I think that the lowest i have seen HP is at about 3,100 RPM (agian - these are for any decent hp/torque 200+ in each catagory) But for Racing applications - you wish to have a split. Torque in the low end and HP in the higher end.

For this application I'd personally like to see a diesel engine. The RPMs are kept much lower, and the torque is needed here (and lots of it.) Gas is better for speed - but diesel is best for getting off the line/heavy loads.

And for the Peak HP/Torque curve and the redline - rember you have gears in your vehicle. When you shift at your redline - you idealy will be right in the middle of your power band (from the taller gearset) - so you get the most pulling power when you shift.

[kacz100]

Originally Posted by Matt Attallah

For this application I'd personally like to see a diesel engine. The RPMs are kept much lower, and the torque is needed here (and lots of it.) Gas is better for speed - but diesel is best for getting off the line/heavy loads.

MMMM propane injection...

[Matt Attallah]

Originally Posted by kacz100

MMMM propane injection...

Propane > NOS for this application.

Personally i'd choose diesels now a days for how much more efficent they are over gasoline engines.

Turbo Cummins diesel 5.9 in a Dodge ram 3500 dualie...:drool:



(Durmaxs are junk.)

[kacz100]

Originally Posted by Matt Attallah

Propane > NOS for this application.

Personally i'd choose diesels now a days for how much more efficent they are over gasoline engines.

Turbo Cummins diesel 5.9 in a Dodge ram 3500 dualie...:drool:



(Durmaxs are junk.)

My dad has the 7.3L Ford diesel..20mph+ after his turbo problem he hasn't had any problems...but Fords are cheap, we need to put some extra springs in the front end because the frontend went down 2 inches...

Diesels rule and gas drools (at the sight of a diesel engine)

[Adam Y.]

My dad has the 7.3L Ford diesel..20mph+ after his turbo problem he hasn't had any problems...but Fords are cheap, we need to put some extra springs in the front end because the frontend went down 2 inches...

Diesels rule and gas drools (at the sight of a diesel engine)


My dad has the 7.3L Ford diesel..20mph+ after his turbo problem he hasn't had any problems...but Fords are cheap, we need to put some extra springs in the front end because the frontend went down 2 inches...

Diesels rule and gas drools (at the sight of a diesel engine)

Well while were on the topic of gasoline engines there was an article in this month's Popular Science about an Indian mechanic who created a gasoline engine capable of running a car without a transmission by only using a dremel tool. Now we just need to see if this modification is useful in more modern cars.

[Matt Attallah]

Originally Posted by kacz100

My dad has the 7.3L Ford diesel..20mph+ after his turbo problem he hasn't had any problems...but Fords are cheap, we need to put some extra springs in the front end because the frontend went down 2 inches...

Diesels rule and gas drools (at the sight of a diesel engine)

I agree for the most part - but Diesels have their place just as gas does.

I'd just like to see a lot more american/imported to america vehicles have Diesel engines. That's the main problem with the MPG of the bigger vehicles (suv, truck, ect...) - you need more torque to make that heaver load go - more power = more gas - and gas works at a lower compression ratio compared to diesel (gas runs at about 8.5-9.0 : 1 on most gas, diesels run anywhere from 14.0 - 22.0 :1 compression ratios.) And diesels can run much, much leaner than a gas engine can. And you can run your diesel engine off of Vegatable oil!! (http://www.greseal.com)

[Adam Y.]

And you can run your diesel engine off of Vegatable oil!! (http://www.greseal.com)

You can't run it without modifications. If you do you'll destroy all the rubber gaskets. Also if I remeber correctly running an diesel engine off of vegatable creates more emissions than running it off of regular diesel fuel.

[Matt Attallah]

Originally Posted by Adam Y.

You can't run it without modifications. If you do you'll destroy all the rubber gaskets. Also if I remeber correctly running an diesel engine off of vegatable creates more emissions than running it off of regular diesel fuel.

For the gaskets - if you pay attention to the site - first off you need to start it with the regular diesel. Secondly that was the orignal point for Diesel engines was to run off of peanut oil. Third the site claims that it has more lubercation properties than regular Diesel fuels. They are even running a Mack Semi on this stuff hauling a trailer (the huge 14+ Liter Straight Six engine)!



I'd personally run the vegatable oil in my vehicle...

(Sorry - Here is the right site - http://www.greasel.com)

[suneel112]

Is the ONLY reason that gas is better than electric motors because it is easier to carry around gas power? If there was an easier and more efficient (more energy per weight or something) way to carry around electricity, would electric motors replace gas? Maybe one idea is to have a nickel-metal hydride fuel cell to power the electric motor. That may last a while, and you can recharge it. I am looking into an idea like that myself. The distance from my school to the Purdue math building is about 1 mile, and it will be tough when it starts snowing. There is also no parking anywhere near the math building (C Permit). So maybe I can make a NiMH Fuel Cell mobile that folds up like a bike and ride it to math. Or maybe not...

[Matt Attallah]

The problems with electric is the power source. It can be big, clunky, heavy, etc... Also - the Size of the motor can be a problem too. Sure - you can get a 72 Volt system or what ever - but than your power source won't last long at all. That is why for most purpoces gas will be used for transporting something or use the electric motor for the low end and the gas motor for the upper (coasting) end...

[coreyjon]

unfortunately, electricity has nothing when you compare its power density to gas, I wrote a lot going into details, then my browser crashed, so, I'm just gonna leave it at that.