Engine Cleaning Before Assembly

I'm working with a cast iron block, and I'm a bit hesitant to use soap and water (paranoid about rust). Also, from a practical stand point, I'm building the motor in my basement and it'd be a bit of a nightmare to spray down with a hose after using soap and water.

The block has been decked and bored by a machinist, then followed with a hot wash. I'm now in the process of re-tapping head/main stud holes, and grinding off some casting flash, so I'm making things a bit dirty, but not too bad.

Since things are relatively clean, I'm thinking of just using brake cleaner and dry compressed air. Anyone have thoughts on, or experience with a similar situation?

Different folks will have different suggestions, but my 5c worth.

The biggest issue with cleaning a block, or most other engine parts, is ensuring ALL the oilways are spotlessly clean and free of debris - that's probably the fastest way to destroy an engine, followed by preventing rust.

Normally you'd remove all the plugs that are accessible/removeable, and pressure wash with detergent/degreaser alternating with a range of "bottle brushes" or engine cleaning brushes, before thoroughly rinsing and drying, before applying a protective coating as one wishes.

You could have your machinist run it through the cleaner, again, but a possible alternative is if you have one of the car washes in your area that uses the manual sprayer/jet rather than drive through type.

Use the engine degreaser and hot rinse, if an option, and follow up with (lint free) towels and brake cleaner or WD40 to blow out the bolt holes, and you should be fine. It helps if it's a hot, low humidity, day.

Take your time and be thorough, and after the drying and WD40 spray to protect against "flash", or superficial surface, rust cover the engine with some large rubbish bags taped in place, to prevent it picking up more dirt on the tacky surfaces.

Give it more drying and blowing out when you get back to your garage.

Thanks for all the advice Gord.

I spent part of last night grinding casting flash off the block, and I now think the hot water & soap route is a must. I'm starting to feel like my brake clean / brush / blow dry only thought really wouldn't have been thorough enough, and this doesn't seem like a part of the build I should be getting lazy with.

People with ultrasonic cleaners swear by them. If you get it pretty clean someone might let you pay a few bucks to use theirs. Otherwise Gord's method doesn't require fancy tools.

My main suggestion is whatever you do, do a little extra. I never feel like I'm wasting time putting in extra effort because the consequences of not getting all the debris out are so unpleasant.