Boxer 4 cylinder engine

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Igor_toko

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Hello all

I´m Igor and I am new to this forum. First of all I want to apologize if I say something ignorant in this post, I am a beginner in this hobby and do not have much experience. I am designing a boxer engine that I want to build. I took the blueprints from the VW boxer engine and simplified it to make it much easier to build. I have no previous experience in building engines, although I have always been interested in the subject.

I am just beginning to do the CAD design and would highly appreciate your feedback. I tried to scale the dimensions of hte VW engine by 1:6 approximately, although some dimensions are not accurate. The Bore is 16 milimeters and the stroke is 14mm.
1659945255097.png

I simplified the cylinder heads and the valve system to make it easier to machine
1659945687178.png


The theoretical compression ratio (volumetric) is approximately 10 to 1 with this geometry. I intend to use spark ignition for this engine.

I intend to cast the engine block out of aluminium using the lost-pla technique (if it works, if not I will go for something else) and the rest of the part will be machined. I have a mini lathe and intend to get a vertical vice for milling operations.

For the camshaft profiles and angles, as well as the ignition diagram, I do not know which values to use and how much of error margin I have.


Do you think this engine could potentially work or are there any major design flaws?
 

minh-thanh

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Hi Igor !
Hello all

I´m Igor and I am new to this forum. First of all I want to apologize if I say something ignorant in this post, I am a beginner in this hobby and do not have much experience. I am designing a boxer engine that I want to build. I took the blueprints from the VW boxer engine and simplified it to make it much easier to build. I have no previous experience in building engines, although I have always been interested in the subject.

I am just beginning to do the CAD design and would highly appreciate your feedback. I tried to scale the dimensions of hte VW engine by 1:6 approximately, although some dimensions are not accurate. The Bore is 16 milimeters and the stroke is 14mm.
My suggestion: make an engine with 1 cylinder
When you make it run, you won't be too worried about this engine
I usually choose: ID cylinder : 16mm , stroke :16mm .

For the camshaft profiles and angles, as well as the ignition diagram, I do not know which values to use and how much of error margin I have.

You can use the cam lobe parameter posted on the forum (search in the forum)
And try with 1 cylinder engine, - I think it's fine
 

Igor_toko

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Hi Igor !

My suggestion: make an engine with 1 cylinder
When you make it run, you won't be too worried about this engine
I usually choose: ID cylinder : 16mm , stroke :16mm .



You can use the cam lobe parameter posted on the forum (search in the forum)
And try with 1 cylinder engine, - I think it's fine
Hello Minh, thank you for the response.

I thought of making the engine with one cylinder first, utilizing the same block, crankshaft, and cam shaft, so that once I get it to work, using one cylinder, I can add the other three.

And I will try to find the cam lobe parameters on the forum that you mentioned.


Thank you!
 

stevehuckss396

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10 to 1 compression is pretty high for a model. If it's a display engine and not intended to do work, consider cutting cutting that in half. In my engines I shoot for between 5 and 6 to one.

As for cam specs, find out what a stock VW cam profile is. The cam has allot to do with the sound and attitude of the engine. With a low compression, realistic cam profile and the right exhaust pipes it could have a nice idle and sound like a full sized VW.
 

ozzie46

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See if you can find the plans and build instructions for Len Mason's Mastiff 4 cyl water cooled boxer engine. Except for the finned cyls in your drawings it looks very similar.

Ron
 

minh-thanh

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Igor !​

I have designed - several engines - just started with cylinders - piston- rings

If you want, I will send my cam lobe parameters to you .
 

Igor_toko

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0 to 1 compression is pretty high for a model. If it's a display engine and not intended to do work, consider cutting cutting that in half. In my engines I shoot for between 5 and 6 to one.

As for cam specs, find out what a

Igor !​

I have designed - several engines - just started with cylinders - piston- rings

If you want, I will send my cam lobe parameters to you .
That would be great if you could share the parameters with me :)
 

Igor_toko

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See if you can find the plans and build instructions for Len Mason's Mastiff 4 cyl water cooled boxer engine. Except for the finned cyls in your drawings it looks very similar.

Ron
Hello, I did not know about this engine, but once I searched for it, it´s quite similar to the one I am designing
 
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Welcome Igor,
Many experts on this website, so I am sure you'll find lots of help. But remember "time zones". This is a global site and you can get time delays while the world turns to daytime and people read your stuff.
Glad to have your company with your build.
K2
 

awake

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Welcome to the forum, Igor! I too would recommend starting out with a single cylinder engine. You will learn a great deal in the process, all of which will better equip you to tackle the challenge of a 4-cylinder engine. Along the way, it is very likely that you will have some struggles; even the most experienced model engine builders do. When that happens, take a break, relax for a bit, and let your subconscious work on the problem; very often you will come back not only refreshed but with new insights into what went wrong. Eventually you will hear the first rumble of the engine running, and it will be a wonderful feeling!
 

minh-thanh

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Igor_toko !​

- First : Make cylinder + piston ( ring or not ring . cast iron ring or O-rings ) and try compression - suction with just your hand
If you are ok with the simple test then you continue to do the other parts.
 

Igor_toko

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Welcome Igor,
Many experts on this website, so I am sure you'll find lots of help. But remember "time zones". This is a global site and you can get time delays while the world turns to daytime and people read your stuff.
Glad to have your company with your build.
K2
Hello
Welcome Igor,
Many experts on this website, so I am sure you'll find lots of help. But remember "time zones". This is a global site and you can get time delays while the world turns to daytime and people read your stuff.
Glad to have your company with your build.
K2
Hello,

Thank you a lot for your welcoming :) I'm happy to join this community and document my process as well as learn from experienced members like you :)
 

Igor_toko

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Welcome Igor,
Many experts on this website, so I am sure you'll find lots of help. But remember "time zones". This is a global site and you can get time delays while the world turns to daytime and people read your stuff.
Glad to have your company with your build.
K2
Hello
Welcome Igor,
Many experts on this website, so I am sure you'll find lots of help. But remember "time zones". This is a global site and you can get time delays while the world turns to daytime and people read your stuff.
Glad to have your company with your build.
K2
Hello,

Thank you a lot for your welcoming :) I'm happy to join this community and document my process as well as learn from experienced members like you
Welcome to the forum, Igor! I too would recommend starting out with a single cylinder engine. You will learn a great deal in the process, all of which will better equip you to tackle the challenge of a 4-cylinder engine. Along the way, it is very likely that you will have some struggles; even the most experienced model engine builders do. When that happens, take a break, relax for a bit, and let your subconscious work on the problem; very often you will come back not only refreshed but with new insights into what went wrong. Eventually you will hear the first rumble of the engine running, and it will be a wonderful feeling!

Welcome to the forum, Igor! I too would recommend starting out with a single cylinder engine. You will learn a great deal in the process, all of which will better equip you to tackle the challenge of a 4-cylinder engine. Along the way, it is very likely that you will have some struggles; even the most experienced model engine builders do. When that happens, take a break, relax for a bit, and let your subconscious work on the problem; very often you will come back not only refreshed but with new insights into what went wrong. Eventually you will hear the first rumble of the engine running, and it will be a wonderful feeling!
Hello,

Thanks for your feedback. I will start by only doing one cylinder and trying to get it to work :)
 

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