How to design an engine
- Thread starter Ukko
- Start date
Help Support Home Model Engine Machinist Forum:
Mechanicboy
Well-Known Member
- Joined
- Jul 10, 2013
- Messages
- 956
- Reaction score
- 343
Anatol
Well-Known Member
Jens, generous spirit that he is, has taken your question seriously.
I guess the majority of readers just rolled their eyes
How to build an atom bomb?
How to become a millionaire?
How to play the flute?
Your question is like these.
The general answer is:
study hard for many years in relevant fields,
carefully examine previous successful examples,
have several hundred design ideas which you then
build prototypes of and
carefully study the way they fail, and
learn from your experience.
Its as easy as that!
My response is actually very serious. The modern 'maker' culture suggests that making is easy. That's just because they want to sell you junk.
Thomas Edison said "I haven't failed, I've found 10,000 ways that don't work"
Making new stuff that works is (irreducibly) difficult.
Get ready to fail. Don't give up.
- Joined
- Jan 7, 2012
- Messages
- 32
- Reaction score
- 7
"Aircraft Engine Design" by Liston is at the "Internet Archive".
Anatol
Well-Known Member
review all the failed designs at the museum of retro technology
http://www.douglas-self.com/MUSEUM/museum.htm
to avoid repeating old mistakes.
http://www.douglas-self.com/MUSEUM/museum.htm
to avoid repeating old mistakes.
lohring
Well-Known Member
- Joined
- Aug 6, 2011
- Messages
- 440
- Reaction score
- 157
Are we talking about model IC engines? Two stroke or four stroke? My favorite book on the history of full size engine design and development is Sir Harry Ricardo's The High Speed Internal Combustion Engine. The paper back edition is much less expensive but lacks the great fold out drawings. Another definitive work is The Internal Combustion Engine in Theory and Practice. On models try http://modelenginenews.org/ for a historical look. Modern two stroke design is discussed extensively by some world experts on this thread on Kiwi Biker. Pit lane has even more. The internet has extensive content but you need to learn to filter out a lot of BS.
Lohring Miller
Lohring Miller
Last edited by a moderator:
Neat stuff there.
Ukko, I assume you're not wanting to reinvent any engine.
I like to "design" my own. Of course I'm not inventing anything, but I design builds that utilize my skills, equipment and on-hand materials.
If that's the case, I suggest you download a basic CAD program and learn how to use it. Draftsight is one such program... easy to use and free.
Russ
I like to "design" my own. Of course I'm not inventing anything, but I design builds that utilize my skills, equipment and on-hand materials.
If that's the case, I suggest you download a basic CAD program and learn how to use it. Draftsight is one such program... easy to use and free.
Russ
Mechanicboy
Well-Known Member
- Joined
- Jul 10, 2013
- Messages
- 956
- Reaction score
- 343
The book from 1942.. Really old book
https://archive.org/stream/in.ernet.dli.2015.205331/2015.205331.Aircraft-Engine#page/n1/mode/2up
Get a degree in mechanical engineering and then add many years experience!
Sorry, but for once I could not resist.
If you are interested in steam then 'Model Stationary and Marine Steam Engines' by K N Harris remains a very good starting point.
In this world of expecting everything to be available for free on the internet, one of the best things you can still do is to sit down for several hours with a book, printed on paper.
Before you start to even think about designing an engine regardless of what type you need to understand how it works and then break it down into its basics.
Type of engine - 2or4 cycle internal combustion , rotary , steam or turbine .
What fuel it will use , gasoline , nitro , diesel , lpg etc or steam powered .
Capacity and number of cylinders or rotors .
Form factor , flat or boxer , v type or radial type for piston engines .
Air or water cooled .
Pushrod or ohc for four cycle .
From there you really need to gain an understanding on things like bore to stroke ratio , con rod ratio , compression ratio , valve or port timing events , rocker ratios for pushrod four cycle engines .
Many of these things can be learned online or in some engine blueprinting books and the books mentioned above .
Cad programme would be the ultimate but many an engine has been designed on a piece of paper with basic drawing tools and basic layouts done with cardboard and paper clips !
This is where 3d printing really comes into its own as you can design in cad , slice and print prototypes much faster than you can machine them !
Asking how to design an engine really doesn't give us much to work with and it is difficult to gauge your experience with machining or engines and we still don't know what type of engine you are asking about !
Type of engine - 2or4 cycle internal combustion , rotary , steam or turbine .
What fuel it will use , gasoline , nitro , diesel , lpg etc or steam powered .
Capacity and number of cylinders or rotors .
Form factor , flat or boxer , v type or radial type for piston engines .
Air or water cooled .
Pushrod or ohc for four cycle .
From there you really need to gain an understanding on things like bore to stroke ratio , con rod ratio , compression ratio , valve or port timing events , rocker ratios for pushrod four cycle engines .
Many of these things can be learned online or in some engine blueprinting books and the books mentioned above .
Cad programme would be the ultimate but many an engine has been designed on a piece of paper with basic drawing tools and basic layouts done with cardboard and paper clips !
This is where 3d printing really comes into its own as you can design in cad , slice and print prototypes much faster than you can machine them !
Asking how to design an engine really doesn't give us much to work with and it is difficult to gauge your experience with machining or engines and we still don't know what type of engine you are asking about !
This type of engine has been designed many many times before. Look at what has been designed before and proven to work. Build one or two of those proven designs yourself so you can learn for yourself the practical side of construction. Then start your own design by combining what you consider to be the best of several existing designs. Plenty of free IC engine plans on the net if you trawl around. Look at sites such as Jan Ridders, John-Tom Engine Plans, or google some of the recognised designers of teh past such Edgar Westbury (aka ET Westbury) and LC Mason. Plenty of their plans floating around on the net.
Best to start with these existing plans because, realistically, if you have to ask "How to design an engine" your are not ready to design an engine yet. You must learn to walk before you can run.
Best to start with these existing plans because, realistically, if you have to ask "How to design an engine" your are not ready to design an engine yet. You must learn to walk before you can run.
Yes it can
Ok now you know what you want to design now you need to add a few things like:
Type of fuel and ignition type ( spark or glow ) so you can aim for a compression ratio.
Overhead valve or side valve ?
Is it to be an open or closed crank design ? ( open has no crank case and is only good for short runs and closed has a crankcase and oil supply and can be run much longer ) open design is easier to machine .
Does it need to be constrained to a certain set of dimensions ? This will govern engine capacity and thus bore and stroke dimension , also if the engine is big enough you may be able to use commercially available parts like pistons , rings ,conrods and valves etc.
If i'm guessing correctly when you asked about one piece culynder you mean cylinder and crankcase ?
Type of fuel and ignition type ( spark or glow ) so you can aim for a compression ratio.
Overhead valve or side valve ?
Is it to be an open or closed crank design ? ( open has no crank case and is only good for short runs and closed has a crankcase and oil supply and can be run much longer ) open design is easier to machine .
Does it need to be constrained to a certain set of dimensions ? This will govern engine capacity and thus bore and stroke dimension , also if the engine is big enough you may be able to use commercially available parts like pistons , rings ,conrods and valves etc.
If i'm guessing correctly when you asked about one piece culynder you mean cylinder and crankcase ?
lohring
Well-Known Member
- Joined
- Aug 6, 2011
- Messages
- 440
- Reaction score
- 157
A two stroke is a much simpler engine to start with. Below is an engine I built in high school. It was patterned after a racing engine of the time (1950s) and taught me most of what I know about machining. You don't need castings. This is a post on a very simple design and this is a plan book on several very successful, simple designs.
Lohring Miller
Lohring Miller
