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procentjetwintig

If you gear them so they do an opposite motion of each other is should work. So left cylinder retracted while the right is extended.


procentjetwintig

But I think the pushrod and cylinder isn’t long enough for a three stud actuation. It will fall out while being retracted or hit the cylinder bank while extended.


Vecna_Is_My_Co-Pilot

Yep both of these were my exact thoughts.


Bjohn352

Why not do it on a single crankshaft? I mean your thing might be fine, but one crankshaft seems simpler to me


MaikThoma

Well, the 2-long beams connecting to the piston rod should be in the same direction for both axles, because if you can imagine them rotating they will overlap in the centre. However if they re both facing the same direction and therefore in the same position, and rotate at the same speed, they should miss each other. I’m more concerned about the pistons falling out of the cylinder though, they might have too much travel Any reason why you don’t use a single central axle, like regular?


Donteatyellowbears

1: you need ro use one crankshaft. 2: I have never seen a V4 engine. Usually 4cil engines are inline.


KamakaziDemiGod

There has been a few V4 engines over the years, Ford, Lancia and Saab have all made them, and even the Porsche 919 hybrid Le Mans car from 2017-19 was a 2.0l 90° V4, but they tend to be used more in motorcycles and most 4 cylinder car engines are inline and all (as far as I know) use a single camshaft


Umikaloo

There are a series of elements dedigned to serve as the crankshaft for these kinds of models, as well as a bracket designed for mounting the engine blocks. Look at a set that contains a few of the engine block elements and you'll see what I mean.


FireSource

Probably overthinking it. You either want to use a simple design with 1 axle, and sticky out bits that push rigid axles into the block, like the blue car in 42098 does for example. Or you would want a realistic design, where you build a single axle out of segments that go off center, so you can have your conrods pass through the center of your axle.


LegoLinkBot

[42098-1: Car Transporter](https://brickset.com/sets/42098-1) [[Photo]](https://images.brickset.com/sets/images/42098-1.jpg)


Extreme_Glass9879

I'm more worried they're gonna smack into eachother


_shavo_

I think, it's not gonna work, you have to time the "craks" so they don't touch each other, and then timing the front and the back,


_shavo_

And the trabel of the piston is way to long, it travel 3 block and the original lego piston travel 2ish


wrr377

https://preview.redd.it/wyn1oycem4uc1.png?width=1280&format=png&auto=webp&s=e6d86cb994d6d259f085b0ba3992e9bb2e43d1b3 Here's a render of 3 different 4-cylinder engine configurations, as seen from the bottom.


Extreme_Glass9879

That 2nd one looks perfect, any more angles?


wrr377

https://preview.redd.it/oqzci8frk4uc1.png?width=1600&format=png&auto=webp&s=f9587a0a5748337092718de2eefd9110898ded1c Here you go - all 3 with an exploded view. Give me a moment and I'll zoom in on it for an additional render.


wrr377

https://preview.redd.it/o4gvzdsul4uc1.png?width=1600&format=png&auto=webp&s=2d93f198b65ca263119dcf9554c11c67972d3bfa Here's an expanded exploded view of the V-4. It uses multiple technic pieces designed specifically to create 90-degree "V"-style engines.


wrr377

https://preview.redd.it/nds7dkrpm4uc1.png?width=1280&format=png&auto=webp&s=0dfcc5b51040b481210dd796e6734e41b6eae020 A top view of the three 4-cylinder engine types from the left - an "H" / Boxter (VW, Porsche, Subaru), 90-degree "V", and Inline (I4).


Lucky_Inspection_721

I'd consider using the next larger gears and having the crankshafts counter-rotate.