Miniature 21cc 4-stroke 6-cylinder Engine that Really Works | StirlingkitMay 19, 2023
I have a cool thing that I want to show you. This is a tiny 6 cylinder 4 stroke 21cc engine that runs on petrol and comes as a kit. It has distributors, ignition coils, crankshaft, everything.
One small detail I noticed while assembling this engine was that the supplied spark plugs were too large for this engine. So, I contacted Stirlingkit and told them about the situation. They promise to send the spark plugs that fit, it will take a few weeks but I've put them aside first. In addition to the spark plugs, this electronic kit also contains the electric ignition system.
They sent me some new spark plugs at no cost. Now that I have the electronic system and in these little bottles, or cans, I have spark plugs, I can't see any difference. I like that they are protected from damage. But look at these tiny spark plugs, wow, they look much smaller than the ones that were sent to me earlier. Well, these black spark plugs are what I'm going to use. Maybe I can use those big spark plugs for something else later. I think they can be used for other types of engines, not just Otto engines, this is one kind of engine as well. I mean, it's not another engine, it's another type of engine, hahaha. I think it can use gasoline. Before following the cams, it is important to adjust them.
We need to put a caliper on the spark plug. The instructions suggested using an aluminum plate, but I decided to try a caliper because it was more flexible. Well, I'll dig into my curiosity to see if I have a caliper. So I found a watch strap that my dad gave me a long time ago. It is a small tool used to measure. Actually, I don't know its official name, if anyone knows please let me know in the comments. It can measure 10 millimeters or a centimeter of the same size, done with the help of a triangle. Well, it's like a multiplying lever, and as you move it across the ruler, you'll see it get bigger.
I have made great progress in engine assembly and tuning. I successfully connected the gas lines, built the electrical system, and installed a button to activate the engine. My goal is to make sure the battery, button, ignition, and coils are all connected properly so that each cylinder produces a spark. However, I ran into some problems.
The first is the use of Hall sensors. In order for the sensor to detect the magnetic field of the magnet and send the spark at the right moment, I need to mount it correctly. After some research, I found out that the sensor needs an overlay tape for proper function. I also found a magnet with holes for sensor detection. This way, the sensor sends pulses to each piston correctly.
Another issue I've run into is the lack of documentation coverage. Due to the lack of instructions, I had to adjust the distributor myself to make sure everything worked. I also noticed that there is a magnet under the dispenser that allows the sensor to detect the correct point or moment to send the spark. I documented these details for future reference.
During the assembly process, I also encountered some challenges. I'm trying to mount the sensor to a similarly shaped thermal junction. I need to carefully fold the sensor to fit the surface. Also, I need to clean all the touchpoints to make sure everything is running smoothly. I checked the spark plugs for sparks to make sure they were connected properly. Once assembled, I was able to turn the distributor to adjust the timing and disconnect a spark plug to see if a spark jumped out.
I did a series of checks and debugs to make sure the engine was working properly. I double checked the timing alignment of the gears and adjusted them according to the manufacturer's recommendations. I also checked the opening and closing of the valves and made sure the spark plugs fit well and there were no leaks. During the inspection, I found some valves were closed while others were open to allow the exhaust to proceed smoothly.
I also did a double check of the electrical system to make sure the spark plug cables are properly connected and that the current is properly distributed from the distributor to the individual spark plugs. I also verified the spark plug installation to make sure there were no leaks. I also checked the position of the throttle and tried adjusting the throttle point to see
I've made a lot of progress with the engine. Now, the gas is connected and I've finished installing the electrical system. Here only the push of a button is required to activate the engine. I hope everything works fine, just wanted to give it a try. Instead of a single command to deliver spark to each cylinder, my battery is connected to the button, ignition and coil. The problem is that in a real engine it spins like this and the spark is delivered through a different cylinder. To solve this I installed a hall sensor, good hall sensor is already connected to my coil so it comes with this sensor.
Then, I found out that the sensor was covered with documentation tape. I realized that since it wasn't mentioned in the instructions, I had to turn on the distributor. If you look closely, you'll see a magnet with a hole in it. With magnetic waves, a sensor can detect it and then send a spark at the right location or timing. At that position or timing, this track crosses the other tracks, sending pulses to each piston, making sure everything works.
I have seen some videos where they have assembled the engine. I realized I had to open it up, luckily the sensor comes with a connector so we can install it later. I removed the thermal junction and it's actually the same shape as the sensor. I wanted to see how it would be placed, so I put it into this form. Now we're going to assemble it, just put it in, and check the movement. I'm going to sand down here as well, as on older cars, all the contact points have to be cleaned as they get rusted and damaged. Cleaning the touchpoints keeps everything running smoothly. I also checked the little spark plugs I showed you to see if there was a spark. I said in the manual that there are two ways to connect but let me open your belly here we have here a distributor that spins from the center to get the current out and distribute it to all the spark plug cables.
Now I'm going to reassemble everything. We will be able to rotate the dispenser to adjust the time. I disconnected a spark plug to see if it sparked and connected it to the coil. Hopefully we'll see the spark jump from here to the engine. I also verified that the spark plugs fit fine, as I could see some of them leaking. I tightened them carefully because they are small and if damaged the spark plugs would fail and I needed the gasoline mixture.
See the video for more details.