Elmer's Turbine and Pump would be an excellent beginner project Dave, as would many of Elmer's engines on Jon Tom. However the OP complained before when someone suggested one of Elmer's engines because they weren't metric…..
…Even though 1" = 25.4 mm and calculators are not hard to come by.
….Even though #2-56 is very similar to M2, #4-40 is very similar to M3, #8-32 thread is very similar to M4, #10-32 is very similar to M5, etc.
No reason Elmer's simple plans with relatively few dimensions could not be easily converted to metric for one's build with just a minor effort.