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Stagger 4 engine CAD

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WonderousMountain

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Screenshot 2015-08-09 at 19.06.42.pngWell, I'm at it again. Some good news, the cooling scheme is simpler!

The crankshaft actually centers on the bores, for once. Plus I can guide my lofts to a basic shape, and it's very compact, at 13 cm deck height.

No idea on dynamic balance, but it's an even firing engine now!

Considering some crankshaft options, as drawn the journals overlap 7.5mm, or 1/2 the radius of 3. 500cc now, let's face it, I'm out of touch with the market and reality, but more focused on my own work, which is an improvement for sure.

Criticism welcomed, but try to keep it directed to potential improvements,

Thank you,

LuPi
 

don january

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interesting on what your doing. Have you done any on hand with real engine yet? What block? I've taken a 2.2 LT. diesel engine and cut it down to a 2 cyl. been dealing with crank and cam. Just wondering if you started with a core engine yet? CROSS VW 3.jpg
 

WonderousMountain

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Great photo,

I know of no such block to work with. Last engine I touched was a 1.3l 4cyl Suzuki. That engine was transferred along with my friends apartment in some sort of foreclosure.

No great rush here, started on the Greenshack today, a multipurpose 12 x 16 which requires no building code where I live. An ultralight shed ;)

LuPi
 

don january

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your picture kinda look's like a v-8 engine cut down the center to give the look's of a v-4. and here is a pic. of the engine I started with.thermo king engine.jpgI see that your in the drawing stage of your design, was just curious if you started a build. good luck on your hanger/building center
 

WonderousMountain

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Screenshot 2015-08-11 at 00.17.05.png Drew in the journal lubrication straight passageways for the crank. References seemed confounding, but it was scarier in theory. Ought to last well enough for testing at the least.

LuPi
 

WonderousMountain

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I looked up theories on reducing gear noise,

but I think you are correct. There is another gearing setup I've been going over, which is where I will direct my attention.

What appealed to me here was the accessibility of circular geartrains.

LuPi
 

don january

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your last post, #9 look's real interesting and I bet would be much quieter. I can hear the engine now with more of a hum then a growl, cooling would seem better less part's to wear out.....stinson.jpg
 

WonderousMountain

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Screenshot 2015-08-29 at 13.44.49.png

Crank and block in a new dimension. Any small change requires a good bit of tediousness to take place.

Had to add .5mm to the bearings width, and shift the lightening holes above the big end retaining wall. The rotation was going backwards, Maybe it was proper for the euromarket :lick:

That meant mirroring everything, and composing the crank of counter-clockwise 1/4 turn rotations. Also the block had to be resketched for that little bit of downside and the webs move 1mm.

I might be ready to do a first run of the cylinder head cooling passages soon. Although, I might be content with a couple Subaru heads if it moves things alone...
 

WonderousMountain

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Screenshot 2015-09-02 at 09.57.23.png I changed the block continuing one of the angles, making both the block and the ladder frame a little simpler.

Here is the ladder frame crankcase. The holes are placed more for illustration purposes, than a final decision, but I feel they ought be along the bearing support webs more or less. It is 5 bearing like a common straight 4, sidewalls are parallel to block; A hexagon composed of 3 sides from a 12 sided polygon and 3 sides from an octagon. Who'd a thunk it?

The real progress is in the details.

LuPi
 

mcrae0104

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Why 5 main bearings for only 4 cylinders?
 

WonderousMountain

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Valuable question,

With 180* boxer cranks the forces align well with the crank arms, especially at ignition; while that is an option with 90-270 firing, my current rendering uses an even firing cross crankshaft.

Flying arms would substantially load and twist the arms. With 5 mains, (3 middle & front - rear) isolates the force and load path similarly to a I4 configuration that is 5/8th the length. Compared to the I4 it will appear a little squished.

You may have heard that the boxer engine is lightest because it can eliminate 2 webs and much counter weighting. I am taking a different approach currently.

Well, I can't get the image up, but subaru 4 cylinders also have 5 bearings.
 

WonderousMountain

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Screenshot 2015-09-06 at 20.03.00.jpg

Switched over to 4 bolt mains, plus placed the crankcase bolts holes tangent to the block, creating a column effect; they actually line up, bonus points.

More importantly, I have leveled up and gained zebra function!!!
 

mcrae0104

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If you cross your eyes a little bit it's in 3D!
 
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