3D printed engine

I'm making a simple 4 cylinder 4 stroke engine in PLA and resin. Obviously it's not built to run! it's just for show. Never the less, I'd like it to look right. It has exposed valves, no rocker box. So, with number 1 piston at TDC and the plug firing, the two valves are shut. If the firing order is 1,3,4,2, what would all the other valves be doing at this moment?
I've built a series of engines, a beam engine, single cylinder horizontal, 1/4 scale Austin Seven engine, single cylinder vertical, twin cylinder vertical, and now this 4 cyl. I have started designing a 7 cylinder radial but I need to do more research. I might attempt a V12 too. The best things about 3D printing all the bits is that they have no working internal parts (yet).

If number 1 is firing
2 exhaust
3 intake
4 compression

Thanks! I'll do a mock-up on the model to see how it looks.

Eh - should numer 3 not be starting on compression if that is the one firing next ?
- 4 is Intake and 2 is exhaust 

Per                 

Quote from: A7er I might attempt a V12 too. The best things about 3D printing all the bits is that they have no working internal parts (yet).

A7er,  If you fancy a challenge, have a go at printing      https://makerworld.com/en/models/737819-porsche-917-engine.

It's a model of the Le Mans winning Porsche 917 engine. It's a 180* flat, air-cooled V12 with fully functional crankshaft, rods and pistons and gear drives to the four overhead camshafts, which operate the valves in correct sequence. Be warned it's big model, but you may be able to scale the prints to half size.

Cheers

Mike

You will also find Andre Vuillermet's Lycoming o360 airplane engine at:

https://makerworld.com/en/models/1663753-lycoming-o360-airplane-engine#profileId-1760456

It's a very neat little flat 4, which prints well. Sorry but no internals in this one.

Quote from: A7erI'm making a simple 4 cylinder 4 stroke engine in PLA and resin. Obviously it's not built to run! it's just for show. Never the less, I'd like it to look right. It has exposed valves, no rocker box. So, with number 1 piston at TDC and the plug firing, the two valves are shut. If the firing order is 1,3,4,2, what would all the other valves be doing at this moment?

  Each engine cylinder must go through four steps: intake, compression, ignition, and exhaust.
By creating a data table, you will obtain the results :

Thanks for the replies. the engine is finished and don't look too bad! Still drawing the radial.....