A technical question...

[1971Hans]

Recently, I managed to purchase a cutaway engine model, used in schools for technical lessons.

The gear wheels on the back side had many broken teeth. So I got them made 3D-printed.
You will also notice that the piston is missing ; I contacted some local bike- and lawnmower workshops if they would have a matching one.
Most of you will also understand it explains the principle of a four-stroke engine.
But some things on the right side of the engine display do I not understand.

Clearly, the little light on top, in the circle shaped chamber, figures the ignition of the fuel.
But is that a spark plug right from it ? Or should it represent an injection, what means it is a diesel engine ?
And what is the function of the little cam shaft right below. It's on the same axle that moves the outlet valve.
Someone who can explain the system in the T-shaped tube on the right ???
Thanks anyway !

[1971Hans]

I forgot the overall picture...

[stitchdup]

I'd guess its a petrol engine. a diesel would have no need for the spark plug as the glowplugs are only used for starting. The light would represent the spark plug in a petrol engine and would flash depending where the crank is. it should flash at the same time as the fuel hammer moves. does this have a hand crank on it? Thats a cool thing to find, my tech teacher only had a lego technik thing thats similar to that. Yours is much cooler than his was.

[stitchdup]

26 minutes ago, 1971Hans said:

 

This represents the fuel system. Since it would be a lot of effort to fit a liquid system for display, instead they used this. each time the hammer gets hit by the crank the light should flash. the hammer represents your fuel system in a much more visual way for teaching and also makes the display easier to manufacture. The part coming off the side would represent the fuel lines coming from the tank and the part at the crank would represent the throttle/engine speed.

[Ace-Garageguy]

I't represents a diesel engine with a pre-combustion chamber and timed mechanical fuel injection.

The cam drives the fuel injection pump so it squirts at the right time relative to piston position.

The little light bulb simply represents when ignition starts in the pre-chamber, from rising compression.

 

Edited May 14, 2023 by Ace-Garageguy

[Ace-Garageguy]

3 hours ago, 1971Hans said:

...see below...

Clearly, the little light on top, in the circle shaped chamber, figures the ignition of the fuel.    YES.
But is that a spark plug right from it ? Or should it represent an injection, what means it is a diesel engine ? IT IS THE INJECTION NOZZLE.
And what is the function of the little cam shaft right below. It's on the same axle that moves the outlet valve.  THE LITTLE CAM MOVES THE FUEL INJECTION PUMP PISTON
Someone who can explain the system in the T-shaped tube on the right ???  FUEL COMES IN THE LINE TO THE RIGHT. THE BOTTOM LEG OF THE T IS THE INJECTOR PISTON, ACTUATED BY THE LITTLE CAM. FUEL PUSHED UP BY THE PISTON HAS TO OVERCOME THE PRESSURE OF THE SPRING HOLDING THE CHECK-BALL CLOSED. FUEL GOES UP THE TUBE, SQUIRTS INTO THE PRE-COMBUSTION CHAMBER.
Thanks anyway !

Edited May 14, 2023 by Ace-Garageguy

[1971Hans]

Thank you all for the reactions.

I already thought it should be a diesel engine. And these have a quiet complicated fuel system. 

I can move on with that.

[Force]

The light bulb is most likely supposed to represent a glow plug used to help ignite the diesel fumes in pre combustion diesel engines when the engine is cold.

Edited May 14, 2023 by Force

[Reformed_convict]

I love displays that have cutouts in them because thats how i see things in my head when i troubleshooting something even if i have never seen the particular mechanism my mind will still make a split second calculation to what it likely looks like on the inside for which ive always found it to be a fascinating gift for which i never understood how often i was correct for the most part and it assisted as a young man working as a maintenance mechanic and brought me praise from those i worked in under to where the head of the department once said ive never saw anyone walk up to a piece of equipment they have never seen before and within 3 min will be within 3ft of whatever the the problem is for which i said im curious and willing to learn how and why things work and it served me well as he took a liking to me and i was never pigeonholed to a specific category for example mechanical and was allowed to fix new and old from analog to digitial often converting dinosaurs with modern plcs and controls due to a fabricating background straight out of HS as a Tig/stick pipewelder at age 18 thanks to my vocational school having a program with the top welding school at the time in 2000 where the schoolboard worked to helped us get credit as if we were in class at school everyday so we could meet our requirements and credits to graduate normally while in reality we were 17 yr old kids from VA living out of motels in greenville SC half way through our senior yr of HS learning skills at whatever your skill level and ability allowed 4 10 hr days to the reality i was ready to go to work at the top of my chosen profession at that time but i hd to wait 2 months before i turned 18 so i could work on a construction site and 3 months till i would graduate high school which was realistically a unfair go around of the journey man system that existed as it made us really good at passing welding test cause that was all we did so the day after my 18th birthday i was paid $32 hr with $65 a day per diem for my first ever tax paying job on a 3 week shutdown in butler Indiana at a steel mill and i finished that job and walked with my fellow graduating class which was actually a program that has allowed alot of folks from a really poor poverty level community in the mountains that dont have any opportunities for work and cant afford college its rare for  anyone to make 6 figures a yr straight from HS and a example of why we should put funding back into vocational programs so kids learn a skill instead of a exspensive piece of paper from a college so atleast theres an option out there some people are terrible in traditional school but i digress into a rant on my own personal experiences instead of the topic but my meaning is i love all things that show you how things work because being able to make something that didnt exist before from scratch as a thought in your head to an type of invention thats doing a needed function is mankinds greatest ability in my opinion sorry for writing a novel i often cant seem to help it and stay on point

[JollySipper]

4 hours ago, Reformed_convict said:

I love displays that have cutouts in them because thats how i see things in my head when i troubleshooting something even if i have never seen the particular mechanism my mind will still make a split second calculation to what it likely looks like on the inside for which ive always found it to be a fascinating gift for which i never understood how often i was correct for the most part and it assisted as a young man working as a maintenance mechanic and brought me praise from those i worked in under to where the head of the department once said ive never saw anyone walk up to a piece of equipment they have never seen before and within 3 min will be within 3ft of whatever the the problem is for which i said im curious and willing to learn how and why things work and it served me well as he took a liking to me and i was never pigeonholed to a specific category for example mechanical and was allowed to fix new and old from analog to digitial often converting dinosaurs with modern plcs and controls due to a fabricating background straight out of HS as a Tig/stick pipewelder at age 18 thanks to my vocational school having a program with the top welding school at the time in 2000 where the schoolboard worked to helped us get credit as if we were in class at school everyday so we could meet our requirements and credits to graduate normally while in reality we were 17 yr old kids from VA living out of motels in greenville SC half way through our senior yr of HS learning skills at whatever your skill level and ability allowed 4 10 hr days to the reality i was ready to go to work at the top of my chosen profession at that time but i hd to wait 2 months before i turned 18 so i could work on a construction site and 3 months till i would graduate high school which was realistically a unfair go around of the journey man system that existed as it made us really good at passing welding test cause that was all we did so the day after my 18th birthday i was paid $32 hr with $65 a day per diem for my first ever tax paying job on a 3 week shutdown in butler Indiana at a steel mill and i finished that job and walked with my fellow graduating class which was actually a program that has allowed alot of folks from a really poor poverty level community in the mountains that dont have any opportunities for work and cant afford college its rare for  anyone to make 6 figures a yr straight from HS and a example of why we should put funding back into vocational programs so kids learn a skill instead of a exspensive piece of paper from a college so atleast theres an option out there some people are terrible in traditional school but i digress into a rant on my own personal experiences instead of the topic but my meaning is i love all things that show you how things work because being able to make something that didnt exist before from scratch as a thought in your head to an type of invention thats doing a needed function is mankinds greatest ability in my opinion sorry for writing a novel i often cant seem to help it and stay on point

I had the opportunity when I graduated highschool to go to a technical school that taught both mechanical and body/paint classes. Really regret not going...... they not only would have taught me a trade ( I wanted to be a body man/painter ) but would have found me a job after completing the course.....