SONICJK nailed it. Rule of thumb, it takes 5 hp to pump enough air. 10 CFM @ 90 psi is the consumption rate of these blasters. You should have a compressor that puts out 12-13 CFM @ 90 psi. Forget about what it says on a blast cabinet's specs if it says 5 CFM @ 40 psi. 40 spi in a blast cabinet won't blast shit. Below 80 psi, they are pretty much useless. I bought a used 5 hp compressor for $650. It took some searching and waiting to find an adequate compressor for a good price that had a single phase motor. So many of the compressors in that size range are equipped with 3-phase motors. It's a monster with a 60 gallon tank and stands 6 1/2 feet tall. I had to use a come-a-long from an overhead beam to unload it from my trailer.
Larger storage tank does not help if your compressor can't pump enough air. It just means that you have to wait longer for it to come up to pressure. Even with the big ass compressor that I have, it runs continuously when I am blasting. I wish I had a bigger one.
One member of DTT said that he bought a compressor from Sears with a 3 hp motor that produced 13 cfm @ 90 psi. Then he admitted that he had burned out two motors, (so far.) Three horsepower just won't do the job. You have to have 5 hp. I saw a new Kobalt compressor in Lowes for around $850, I think. It's no where near the industrial duty compressor that I bought used.
I use glass bead on carburetors, but soda is better because it cleans the surface with less abrasion. Soda is waaay better for inner engine cases, because it is extremely challenging getting every last bead out of every nook and cranny. You have to be very, very meticulous cleaning them afterward. I will still use glass bead for outer engine covers, heads and jugs, because they are easier to clean, and the glass bead is cheaper to use because it lasts indefinitely. Once I get my big blast cabinet built, I will repurpose my pressure pot sandblaster for use with soda, which I will do outside. My big cabinet will be filled with crushed glass media because it has no free silica, and is cheap. Aluminum oxide would be my preferred media for powdercoat and paint prep, but the crushed glass was only $12 for a 50 lb bag.
It is not that difficult to change the media that you have in a cabinet, but if you switch from glass bead to soda, you are still going to have a problem with some stray glass beads that you would never be able to completely clean out of the cabinet. Metal finishing companies use multiple cabinets, each dedicated to specific media.