Rear Motor Mount and Bell housing
Today I turn my attention to the rear of the engine. I started to work on the bell housing/clutch assembly, but then realized the bell housing attaches through the rear motor mount and extends beyond the sides of the crankcase. So I start with the motor mount. It is relatively simple as it is a single plate of aluminum that bolts to the rear of the engine and to the frame of the race car.
I import the image of the rear of the engine, scale it and import it into my assembly. Then I lay reference datum lines and take measurements. I build the rear motor mount model and check it in the assembly.
Then I do the same thing with the bell housing /clutch.
This is where the rear of the engine is for now.
As per some earlier discussion with Peter, I changed the angle of the valves from 44 degrees to 45 degrees. This change only impacted two components, the green head and the magenta timing gear tower. I also worked on the purple front cover (below), I found I had made it too thin. I added some detail to the magenta timing gear tower to blend it into the front cover.
I now have the basic structure of the engine and can start thinking about the internal components. I will also start normalizing dimensions and thinking about where the critical dimensions are and what tolerances need to be. Up to this point in time I have only been focusing on putting the lines in the correct spot and have not worried what the dimensions ended up being. For example, if a dimension is now .12734" , I will determine if I can change it to .125" or even .12". this process has to be done systematically as these dimensions will ripple through the entire model.
Today I turn my attention to the rear of the engine. I started to work on the bell housing/clutch assembly, but then realized the bell housing attaches through the rear motor mount and extends beyond the sides of the crankcase. So I start with the motor mount. It is relatively simple as it is a single plate of aluminum that bolts to the rear of the engine and to the frame of the race car.
![1640818952609.png 1640818952609.png](https://cdn.imagearchive.com/homemodelenginemachinist/data/attach/86/86130-1640818952609.png)
![1640818968185.png 1640818968185.png](https://cdn.imagearchive.com/homemodelenginemachinist/data/attach/86/86131-1640818968185.png)
I import the image of the rear of the engine, scale it and import it into my assembly. Then I lay reference datum lines and take measurements. I build the rear motor mount model and check it in the assembly.
![1640818999830.png 1640818999830.png](https://cdn.imagearchive.com/homemodelenginemachinist/data/attach/86/86132-1640818999830.png)
Then I do the same thing with the bell housing /clutch.
![1640819029390.png 1640819029390.png](https://cdn.imagearchive.com/homemodelenginemachinist/data/attach/86/86133-1640819029390.png)
![1640819054590.png 1640819054590.png](https://cdn.imagearchive.com/homemodelenginemachinist/data/attach/86/86134-1640819054590.png)
This is where the rear of the engine is for now.
As per some earlier discussion with Peter, I changed the angle of the valves from 44 degrees to 45 degrees. This change only impacted two components, the green head and the magenta timing gear tower. I also worked on the purple front cover (below), I found I had made it too thin. I added some detail to the magenta timing gear tower to blend it into the front cover.
![1640819109995.png 1640819109995.png](https://cdn.imagearchive.com/homemodelenginemachinist/data/attach/86/86135-1640819109995.png)
I now have the basic structure of the engine and can start thinking about the internal components. I will also start normalizing dimensions and thinking about where the critical dimensions are and what tolerances need to be. Up to this point in time I have only been focusing on putting the lines in the correct spot and have not worried what the dimensions ended up being. For example, if a dimension is now .12734" , I will determine if I can change it to .125" or even .12". this process has to be done systematically as these dimensions will ripple through the entire model.