# Cutaway engine



## BMW Rider (Jul 12, 2020)

Thanks to John for the Honda engine he was generous enough to part with for this project.

I have a nephew who is quite keen about cars driving and all related things so wanted to help him learn a bit more about the workings of a gas engine. I picked this engine up a couple weeks ago and worked on it completely stripping it apart and cleaning it up. It's quite old and as such parts are nearly non-existent for it, so the prospect of repairing it to running condition was not possible. I figured a good way to turn it into a teaching tool was to make it into a cutaway model so the functions and sequences could be demonstrated. In the end, it was not much for actual machining work, mostly hacksaw and filing with a few intervals with a cutting disc grinder. A lot of time at the sandblasting cabinet cleaning up all the pieces and a few small fixes. The only direct investment was a can of spray paint and a new rope for the pull start. I fabricated a crank handle using the remains of the clutch hub and a bit of scrap metal. 

I still want to build a nice base to mount it on. My nephew is quite eager to get his first lesson.


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## YYCHM (Jul 12, 2020)

That's awesome!  Nice work.


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## CalgaryPT (Jul 12, 2020)

I'll say.....what a great job. You've got a good eye for visualizing how to do that. I like the red high-lites along the cut lines and the crank handle. Nicely done sir.


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## David_R8 (Jul 12, 2020)

That is exceedingly cool! Well done. 
As a kid I was always fascinated by cutaways of anything mechanical. 
So cool!


Sent from my iPhone using Tapatalk


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## Johnwa (Jul 12, 2020)

That doesn’t look like the same engine.  It is way to clean!


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## PeterT (Jul 12, 2020)

Very nice. I love cutaways. I think there is some discretionary art involved - opening up key areas, cutting delicate things flat, paint detailing... all that to expose underlying features or mechanisms & still keeping the assembly together. Well done.


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## Chicken lights (Jul 12, 2020)

Very nice work! 
I never really understood how a magneto works on one of those, other than it’s the same principle as a generator but completely different 

Suck squeeze bang blow!!


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## CalgaryPT (Jul 12, 2020)

Chicken lights said:


> Very nice work!
> ...it’s the same principle as [_insert what my wife asked me to do_] but completely different


That's pretty funny. I'm going to use that


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## Chicken lights (Jul 12, 2020)

CalgaryPT said:


> That's pretty funny. I'm going to use that


Just so long as when she catches you doing something you shouldn’t be...my name doesn’t get brought up


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## DPittman (Jul 12, 2020)

Very good.  I've always found cut away examples extremely helpful in understanding mechanical things.  I've never been able to understand how they do the cut away so precisely tho?


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