Suzuki GT750 Engine case detailing

This shows my work of cleaning up and repainting the engine case. I used a controversial cleanup method named sand blasting.
Yes, sand blasting ! I am pretty confident I have been able to get every little particle out of the case after this work. But this does not mean you would. So I do not recommend you do this unless you are confident regarding this method as well. The pro's recommend walnut shell media which is less fatal in case you would fail getting all particles out of the case internals.

BEFORE BLASTING

Case must be absolutely free from grease and dirt that would bind the blasting particles. All detail bolted/screwed onto the case halves most have been removed and the case cleaned. Do not proceed otherwise.

Machined surfaces may not be blasted . Little known is that masking tape is a great way to protect these surfaces. Time spent on preparing
masking with great detail is time well spent. The blasting particles do not harm the tape due to its soft material. At least as long as you use hobbyist air compressor capacity. I masked off the areas where the base cylinder gasket go, oil injector inlets, oil pump base, VIN plate. The rest of the outside of the case are painted surfaces.

NEVER blast the inside of the case !!

AFTER BLASTING

Cleaning the case halve after blasting is the most critical thing. If any blasting material remain inside the case when you reassemble the engine this will mean the death to your engine !! That's why this is not a method to recommend unless you are damn sure you are going to master it.

Remove the masking tape from the protected surfaces. This is vital before any cleaning attempt.
Use pressured air to blast off the initial dust after blasting. This is important before washing the first time.
Wash case halve thoroughly. Use hot water and the detergent you wife normally use for washing the bathroom floor. Your bathtub is a great place for this process at least after the first washing attempt.
Bring case halve out in the open air and blow compressed air in every thread and hole and make sure you get the particles and moisture out of EVERY hole and thread. Critical areas are oil injector channels and every thread. Especially on the inside of the case. Use some welding rod or similar to poke into holes to assure any particles are coming loose. If you got some place where you can go wild with a pressure degreasing gun then that helps. There are a few very narrow and deep cavities inside the gearbox case, make sure these are thoroghly cleaned out, otherwise blasting particles will bind to any grease left there.. A pressure degreasing gun is very useful for this.
Repeat 3-4 until it seems ridiculous and pointless to do it once more.. Then repeat one more time. Using hot water means the case will dry up quicker. Every time you blow air into a cavity and a sand particle hits your face you know it's back to step 3.. The degreasing gun is most likely vital.
Case shall be repainted in its original silver grey color. This means the exact same masking procedure as before blasting need to be done once more. Took me two full days to get the case halves to the below condition.

Case is cleaned carefully.
Ready for masking a 2nd time in preparation for paintjob

2nd Masking Step - Preparing for Paint Job

Masked off areas for gaskets and openings where paint is not desired.

Engine case paintwork

I used a quite mainstream engine paint in spray can format. I tested it on the water pump cover first. Kind of slow drying but after given about a day to harden the surface appeared to be very durable. I think the color look right for my purposes at least and there is a certain gloss that should reject dirt and make it easier to clean the case. So I went ahead and painted the case. Here are some photos:

Engine paint