1990 Z32 NA engine bay clean-up

[Zi32]

Recently purchased this car and it has a lot of carbon build-up and gunk and old oil all over the place. what i want to know is how do i properly prep the engine bay for a heavy top to bottom cleaning? I have to do the cleaning before i can assess any problems or any damages in the bay. thank you.

[DCaff300ZX]

I've found that simple green mixed fairly strong works pretty well for intermediate cleaning, while you may have to go with a professional spray product for safe harsher duty. I've used WD-40 before to cut dried crud, then clean the WD off with simple green mix. Dawn dish detergent also has some effective moments once you get down past caked on grime, and you can gently use a old pot sponge green scrubbing side (NOT new!) with the detergent on non-painted surfaces, and MAYBE painted if the scrubbing side is old and worn enough to not scratch the clear coat.
Bug and tar remover can be helpful but be careful leaving on paint too long in some cases, turpentine and paint thinner are about as harsh as you want to go before you may bubble or worse any painted surfaces.
Hope this helps!