Making a generator from a two wheeler engine

I have heard about people making a generator from old car engines but those produce a lot of electricity ,much more than a small house would require.

I can manage an old bajaj scooter to make a generator as I guess this should be sufficient for a small home.Is there anyone who has tried it before or someone who can explain the process?How much current can I expect to be produced from from a 150CC engine?

Would it be prudent to make it into an LPG generator to save running costs?And, also what would be the cost in making it.

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Well, you could easily build a 1-2kW generator giving out 230VAC at 4 (or 8 amps for 2kW) - the hard part I feel is finding an appropriate alternator (NOT the usual vehicle alternator) in the market - if you have managed to get the engine the alternator will cost more than Rs. 5000 (JUST A WILD GUESS!!). Other things to take care of would be the exhaust emissions, noise, etc that the engine will produce.

To get a rough estimate of how much power the generator will give - convert the engine's power into watts - that's the best it can do. A 150 cc engine can manage upto 7hp - so that's about 5.5kW. Practically due to the alternator & mechanical losses you will get about 4.5-5kW.

Thanks Rohit for the technical assistance,

More economical generator would be a diesel one. I have seen in the outskirts of Tamil Nadu people using their bullet's diesel engine as generator in fields. (Please correct me if they weren't used as gen,s.)

NIk!

Nikhil,

Those are used as pumps & not generators, if I am not mistaken.

yeah Rishi, i had a doubt. Regretted.

Thanks for correcting.

NIk!

We should also think about the safety + invironment

I too am fascinated with this concept and has worked substantially on tech side.

I own classic SL delivering 7.5 bhp. Though classically it seems 4 kw possible due to generator curves I think 2 to 2.5 kw is possible.

Problems are

1. Need to shift the engine to apartment balcony. I can sell off the scooter then in scrap yard. I still w'd get the money that I am being offered for whole working scooter. I also w'd get rid of environment tax, insurance etc.

2. Sound proofing. Abt 3-4000 rs plus cabinet with exhaust pipe another 3oo0 Rs.

3. For generation, instead of goind for an alternator I am looking for dyanamo(Permenant Magnet DC generator) of 3 KW, (possible) but need to buy in bulk. I w'd use an existing invertor to convert this DC into AC. This way I will get rid of battery replacement every 3 yrs which costs me 3000 Rs as of now.

I know this would look asthetically absoloutely hopeless but I still have the KIDA to finish this modification off in next 6 motnhs. Luckily classic SL comes with an electric starter.

Though 2.5kw at 240V can provide substantial Amps which invertor might not handle, invertor ususally comes with an overload trip (mine one has) and hence no issues on that front. I don't know how much specific fuel consumption w'd be. I wish to get rid of gear box as it involves losses and instead couple dynamo directly and then adjust 12V o/p by manuall adjusting the speed and reading the voltae with multimeter(i.e. trial and error)

Hope I can make it work.

Don't use a dynamo and then convert that to AC with the inverter - it would just be too inefficient. There are 2 ideas:

1. Tweak the dynamo such that the armature can be held fixed and the coil wires are brought out directly (instead of being connected to the commutator and brush) and then rotate the magnet. This will give you AC directly. The commutator & brush do the job of AC-DC conversion in the dynamo (for a DC motor it works in reverse).

2. Get a car alternator and tweak it - I guess it has a 3-phase winding (each phase with AC output) which is converted to DC using an external rectifier. Remove the rectifier and you end up with a 3-phase 12V AC system. Now use a 12-230V step-up transformer for each phase to get 3 AC outlets.

Hi Rohit,

You seem to know well about vehicles have you heard about water4gas tech? Is it feasable in India? Would it be profitable, gas is pretty cheap here.

Well, water4gas does not work - at least not when you produce the hydroxy gas on-boar the car. The energy needed to produce the gas is much more than the energy boost it gives to the engine.