Making a Four-Stroke Engine

Well, its got some fins and some holes in it - and one of 'em's intended for a Glühkerze ...

So has this...

Del

I thought, as I typed "fins" .... But then I thought (after typing the next bit) "what kinda fish has a hole suitable for a glowplug"?

Well, now I know.

Cat (?) and Fish was awarded the CBCA Picture Book of the Year (Australia) in 2004, shortlisted for the Crichton Award (Australia) and listed in the 2004 International Youth Library White Ravens.

That's enough. Stop dribbling.

Thank you everybody for taking the time to read and answer my topic, it was helpful.

Are these discussions here gave you clarity or confusions?

Drawing is the language of engineers. A well drawn one should not look for much text to reinforce it. Still some standard details like threads, finishes etc do take the benefits of text-based information.

I could map the shape in mind, but for a few details that are indicated as, "Teil 5, Kuhlrippen Untergreze !". What do these mean? Can you translate the texts in this drawing?

If you still need better idea of this specific shape please indicate, I will try to help it out.

It should read:-

"Teil 5, Kuhlrippen Untergrenze"

Which simply means "Part 5, Cooling fins, lower limits".

Yes, maybe I should have translated those specifications for you people, sorry about that, but the main problem here is that this part has been badly drawn (I don't know where my teacher got the drawings from), I had some problems when I tried to represent the solid in solidworks, I could finally do it but I had to assume some information and then fix them when I did the assembly with the other parts... now I'm doing the models for the smelting process, I hope to finish them for tomorrow, there are 22 parts !!

Ok, you've got my curiosity up. Why do you say that this part is badly drawn? What did you have to assume?

Hooker

I'm no expert, but I believe the general term in English usage is "casting" not "smelting" , though the whole "casting" business may be part of a "Smelting" business or works......

smelt. verb (often as noun smelting) extract (metal) from its ore by a process involving heating and melting. For example:- "the zinc ores are smelted in Swansea".

casting. noun. an object made by pouring molten metal or other material into a mould. For example:- "bronze castings".

Its not too important really, we all understood you fully.

I think you have not yet grasped the design of the "head". I can make this with 4 mould components. Look up "cores" and their function in casting.

Wow, sorry to sound down about this but doesn't that university teach blueprint reading and drafting.

That's a problem with CAD systems nowadays. Everybody wants to make pretty models but very few have a clue how to document them.

Hooker

This is a point that often crosses my mind. I am a child of the CAD revolution, having learned on AutoCAD 2.something...

Even though I was one of the few lucky ones that had a chance to use AutoCAD in High School in the mid '80's, I had college and night school courses on the drafting board, and my first job was on the board for the first year. Then I was given the first computer to cross the threshhold of the company I worked for. I had to learn orthographic projection in school using the table, and I still remember that the younger kids around me when I took night school classes (they were just a couple years younger than me) all were totally lost when it came to the orthographic projection related stuff.

They all had computers for years, and all had the computer drafting classes under their belts, but they did not have a clue how to produce an auxillary view - especially to a surface that was not "square to the world". Some day we won't even understand where the knowledge glossed over by the computer ever came from. I suppose if the computer can do it for us we don't need to know that, but it seems like there is some art in the business that gets lost.

You appear to be missing several more drawings for the crank case, piston, carburettor etc...

You are right, thank you for your advice

Take some mechanical (not architectural) drafting classes. I was working with a mechanical engineer who was in the process of getting his masters, and I (draftsman/designer) had to explain the drawings to him. Do not need to take as many as we take, but, need to learn about revolutions, auxillary views, etc. The sketch provided is rather simple example of what can be done.

Of course I took drafting classes, but this particular part was badly drawn, that's why I asked if someone knew what part from a four-Stroke Engine was the drawing or even better if someone had pics related.

Go to a scrap metal yard and ask for an old engine from a lawn mower. I am over sixty and have previous knowledge so for me this was easy. It is the drawing of one part that is called the 'head'. Top left is plan, top right is side elevation, center and bottom left show the hole centers and bottom right is cross sectioned side elevation showing the fin depth ( thanks Andy ).

The plan and side elevation show the inlet and exhaust ports ( holes ) that go through to the valves. As i said this will all be understood once you have look at a "head" from an engine, almost any engine will do as the principle is the same ( alright not two stroke ).

The drawing is for the cylinder head. It utilizes a rotary valve arrangement. This head is similar to many used for small engines world wide with the exception of the rotary valve as most small engines used the disk valve.

To make this part you will need to make a pattern of the part and cast it. The part has fins on the top to cool the head. We make patterns and cast the parts from them using a green sand process and aluminum. The drawing is complete and a pattern can be made from this print. I would not attempt to cast the holes as they can be machined with more accuracy. If you have a CNC machine avaliable you can machine a hard wax pattern and use that for the casting.

What makes you think it has rotary valves?

No provision for valve seats, Rockers, Push rod tubes. The indication of a sleve in the inlet or outlet for a bearing surface.

Could well be right there. Pretty lousy drawing. However, "ventilsitze" is German for "valve seats".

Would be nice to have an assembly drawing to decide the actual engine type & component placement.

A hard valve seat could be an insert in that 15mm dia bore...

But the valve would have to be remotely operated being no provisions for a valve train. Maybe a cable operated compression release?