Aluminum sand casting for Chenery Gnome Rotary

[GreenTwin]

I don't have an expertise in threading holes like that, but I can say that 356 aluminum that has gone through the 2-step T-6 tempering process is much harder and easier to drill/tap without loading up the bit.
Hopefully you can work out a solution.
.

 

[albd5a]

I don't have an expertise in threading holes like that, but I can say that 356 aluminum that has gone through the 2-step T-6 tempering process is much harder and easier to drill/tap without loading up the bit.
Hopefully you can work out a solution.
.

Thank you Twin

 

[albd5a]

Thank you Twin

Can you describe your 2-step T6 tempering process for Aluminum? Thanks.

 

[GreenTwin]

I put the aluminum heat treating info that I use here:

https://www.homemodelenginemachinist.com/threads/heat-treating-aluminum-alloy.36697/

.