"New" (alternative) fake engine idea for inline engines

[Gray Gear]

Hi there

I got the idea to use the small pins with stud on top as cylinders for a fake engine. It allows the pistons to be very short, without a stop underneath/above to keep them in place. I kinda dont want to show you my complete RB26dett engine as it is part of a MOC I am working on, so you'll have to live with this little mockup guy for now 

Sadly this system only works for inline engines, as the pins wont go back down when at an angle, like in a V-engine. The engine runs incredibly smooth, and there is basically no resistance or rev limit.

 

Gray Gear

Edited March 2, 2020 by Gray Gear

[Parazels]

I like your inline engine!

Are those oval liftarms still available in modern sets? I thought this part is gone.

[Zerobricks]

  On 3/1/2020 at 10:19 PM, Parazels said:

I like your inline engine!

Are those oval liftarms still available in modern sets? I thought this part is gone.

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They are, see here:

https://www.bricklink.com/catalogItemIn.asp?itemType=P&itemNo=6575&in=S&v=2&oV=Y&srt=2&srtAsc=D

[Didumos69]

Nice idea, using half pins as pistons is not new though. @Attika used it in a small fake V6.

[Gray Gear]

Yeah, I expected I wasn't the first to think of that. I tested it using a V6, but it didn't work very well...

[Didumos69]

  On 3/2/2020 at 8:00 AM, Gray Gear said:

Yeah, I expected I wasn't the first to think of that. I tested it using a V6, but it didn't work very well...

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Maybe the different crankshaft makes a difference. Anyway, your version is still worth sharing. Thanks!

[Nazgarot]

I've been using a similar solution to simulate valve movement. I find the movement not smooth enough for a piston, but it works very well as a camshaft when timed correctly to simulate valves opening and closing before and after compression. 

But props for the compact design!

-ED-

[Gray Gear]

I used this to make a RB26dett, and in a Inline 6 engine you can't use the normal engine components, because 14 studs of length is just way too much. So this seemed like the best solution to me 

You are right, the piston movement isnt very continuous, but meh, what can I do.

[1gor]

this one looks better that LEGO version in Mack, but I'm still not convinced about such fake engines, perhaps I'll decide one day to make small MOC and i  implement it, who knows.

[nerdsforprez]

Great design but why the clear 1x1 rounded tiles for the heads?  Never seen cylinder heads that are clear.  Why not like metallic or aluminum gray?

[Gray Gear]

  On 3/2/2020 at 3:06 PM, nerdsforprez said:

Great design but why the clear 1x1 rounded tiles for the heads? 

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Because they were the only ones I had left 

[nerdsforprez]

[amorti]

  On 3/2/2020 at 10:14 AM, Gray Gear said:

meh, what can I do.

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Might help to clean the parts, you can see some dirt in the pin holes which might be gumming it up.

Edited March 2, 2020 by amorti
Ofc, blue half pins don't have friction...

[Gray Gear]

@amorti how would that help? I mean that the pistons only move on 1/4th of the crankshafts rotation, and not all the time, like when using a real crankshaft.

[amorti]

Aah, now I see what you mean. 

I thought you meant they weren't moving continuous in the sense of something binding.

[Gray Gear]

Yeah, I can see where you are coming from looking at that 6l Liftarm...

[letsbuild]

I've used this technique bore, as recently as two years ago, though I didn't use the oval cam pieces, I used crankshaft parts.

 

[Gray Gear]

I tried using crankshaft pieces too, and while that definatelly makes for a very compact mechanism, it can only do a very unsatisfying and unrealistic firing order.  I guess in your case there was no choice due to space issues 

Edited March 5, 2020 by Gray Gear