Lego 2-Stroke motor

[Seto]

15 minutes ago, ukbajadave said:

To me the question here is how much non Lego can you use and still call it a lego motor. That video is interesting but is it a Lego motor?

I've dabbled in many things over the years including 1/5th scale RC cars powered by 2 stroke petrol engines. A CY or zenoah flywheel and coil would get you a spark but what are you using for a carburetor?

Please post some pictures of your work so far (use bricksafe or flickr to host)and make sure to video it when you finally fire it up, even if it explodes I'd like to see it!

i dont want yet cuz its so megablocking ugly :d. i dont have decent parts so its ugly. When i get ignition i can

[Seto]

I have two wires close but how i get them spark. U know there come a electrical wave between them

[Jurss]

Put on some sunglases at least before

[bonox]

7 hours ago, Seto said:

I have two wires close but how i get them spark. U know there come a electrical wave between them

you need an electric pulse. An old lawn mower breaking points style magneto will have about 6-8 volts on the primary side and via a coil, comes out at 300-500V to fire the spark plug. You could generate pulses with a small timer circuit and a battery or just a hand switch if you don't need speed, but you're going to need a coil to step up the voltage to your pair of wires.

I should add that a general purpose spark ignition engine commonly has about 15000 volts on the secondary side of the coil. more compression tends to need higher energy impulses.

Edited August 2, 2020 by bonox

[Seto]

5 hours ago, bonox said:

you need an electric pulse. An old lawn mower breaking points style magneto will have about 6-8 volts on the primary side and via a coil, comes out at 300-500V to fire the spark plug. You could generate pulses with a small timer circuit and a battery or just a hand switch if you don't need speed, but you're going to need a coil to step up the voltage to your pair of wires.

I should add that a general purpose spark ignition engine commonly has about 15000 volts on the secondary side of the coil. more compression tends to need higher energy impulses.

sounds bit too hard to make. Electricity isn't my strenght

If i try to make same mechanism like in plasma lighters?

[jshuiting]

You could use one of those CDI's they use on 50cc/125cc racing motorcycles, easy to fit and easy to program.

What's the idea though? You could make a "engine" like the one from the video you posted, but it'll never be able to run on it's own anyway, so why bother with a ignition?

Edited August 5, 2020 by jshuiting

[MinusAndy]

Lego and petrol are both essentially made of the same thing, The petrol will turn the bricks into a mixture a bit like napalm. Please film this!

[TeamThrifty]

2 hours ago, MinusAndy said:

Please film this!

(i'm sure he means 'don't stand too close!!)

On 8/2/2020 at 3:37 AM, Seto said:

I have two wires close but how i get them spark. U know there come a electrical wave between them

spark plugs use high voltage so engines have a coil that transforms 12v into an awful lot of volts.. but V=IR, so as volts go up amps goes down and its unlikely to kill you. The CDI mentioned above would still need a coil (i've spent many hours swearing at motorcycle coils and cdi's and plugs... its all ECU's and fuel injection these days which is generally better..)

But you need a coil to make a spark.. and you need a trigger for that (Points, CDI, ECU)

[jshuiting]

21 hours ago, TeamThrifty said:

(i'm sure he means 'don't stand too close!!)

spark plugs use high voltage so engines have a coil that transforms 12v into an awful lot of volts.. but V=IR, so as volts go up amps goes down and its unlikely to kill you. The CDI mentioned above would still need a coil (i've spent many hours swearing at motorcycle coils and cdi's and plugs... its all ECU's and fuel injection these days which is generally better..)

But you need a coil to make a spark.. and you need a trigger for that (Points, CDI, ECU)

I don't think he really needs a coil as the engine won't build up any compression anyway, even a open flame would do the trick 

But yeah a magnet mounted to the axle, a hal sensor, coil, ignition box plus a sparkplug with the correct wiring would be the most optimal and most simplistic form of ingition, but at that point you might aswell get a real engine and experiment further on that.
Making something that will just melt or fail spectaculary seems like a big waste of time and money to me, some things are just not meant to made out of Lego.

[doug72]

It will be more like One stroke “Bang”

[MinusAndy]

The whole point in us using internal combustion is the range, power and convenience of it. Petrol is just a convenient way to store the energy, why not focus your energy on using an air tank at hoggish pressure and use that as “fuel” to run an engine, you can still build all the valves etc but you take away the heat and solvent issues you will inevitably have from the off?

[ukbajadave]

CY Flywheel £10

CY Ignition coil £14

Spark plug £5

You aren't going to get any cheaper or simpler than that. Looking forward to the video

[TeamThrifty]

3 hours ago, MinusAndy said:

using an air tank at hoggish pressure

I agree! Internal combustion engines are just air pumps in disguise... so remove the combustion element. It is a much better idea... and less injuries. Melted, burning lift arms??! No thanks!!

[Johnny1360]

I look very much forward to seeing this project reach a successful completion. 

I am however very skeptical that it ever proceeds past this point. 

Providing a spark at the exact moment it is needed really seems to be the least of the problems. I would expect that compression and fuel delivery to be more problematic and would like to see these solutions before I could ever hope to advise an ignition system. 

[Jurss]

maybe he could create Diesel, there is no need for ignition system

[Seto]

So guys, BIG thanks to u i got very good tips! And also i wanna tell something, so this is kinda experiment and i just wanna see can i create combustion even once. I dont have even flywheel and the cylinder would just burn so it wont work like real engine. I just wanna test can i build engine what has combustion cose im not engineer. When i get ignition working i will film it upwards so u can see if the combustion happens (i made the top of the cylinder with transparent plastic). I'm so excited to see if i can get even one bang!

On 8/6/2020 at 11:41 PM, ukbajadave said:

CY Flywheel £10

CY Ignition coil £14

Spark plug £5

You aren't going to get any cheaper or simpler than that. Looking forward to the video

WOW dude! Thanks a lot, i may order them today!