Help with engine CAD assembly

[Doka Doka]

Hello, I recently decided I would try to improve my CAD skills and model an engine from technical drawings.

I decided to start with this design because it was relatively simple and had metric dimensions which I am more used to.
http://plans-for-everything.com/downloads/ic_engines/ICG_4Stroke.pdf

As I worked through the drawings I found that they weren't great but they were workable and with a little bit of guess work I was able to model all the parts which you can see here.
https://a360.co/2WArfpT

The main issue comes with assembling, I don't have much in depth knowledge on engines but I was able to get almost all the parts together based on the single drawing on the first page. But without a more detailed view I am unable to work out how the valves fit together.

Any assistance or advice would be appreciated.

 

[kvom]

It seems to me that the heads of the two valves face each other in their respective blocks, with the exhaust valve and large spring placed against the push rod and the admission valve and small spring sticking out the end. The valves seat on the counterbores. As to how it works in operation, I can only imagine that the admission valve opens and closes via air pressure/vacuum causes by the exhaust valve motion.

 

[ruzzie]

Hope this Helps