Engine cleaning solvents

[pivichot]

I have had the engine block back from the machine shop for the last 3 weeks. Tomorrow I am starting to take measurements to make sure everything is within spec. What is a good cleaner to clean the crank, block, and pistons? I was thinking brake parts cleaner but I think it may rust with that. Any suggestions?

[gadget73]

acetone does a nice job to remove all oil. It will rust if you leave it dry though. Measure, then re-oil to keep it from rusting. Pistons are aluminum, they won't rust.

[pivichot]

acetone does a nice job to remove all oil. It will rust if you leave it dry though. Measure, then re-oil to keep it from rusting. Pistons are aluminum, they won't rust.

Ok. Thanks. I would clean the bore out, measure, and then apply oil. About how long would I have before it starts to rust? I would Use a lint free cloth to clean the bore with acetone and then dry.

[DerekTheGreat]

..Pistons are aluminum, they won't rust.

Actually, they do rust. That's why bare aluminum stuff usually comes heavily oiled. Once the oil is removed they rust/oxidize almost immediately, just the naked eye can't see it. Probably doesn't matter with engines but it sure does in the paint/pretreatment business.

[gadget73]

If you find orange iron oxide on aluminum, you've got deeper problems. Yes, it does oxidize but it doesn't turn rusty orange like an iron block will.


How long it takes depends on humidity. The wetter it is, the faster it'll happen. I wouldn't leave it more than a few hours though. Get your measurements and oil it again.

[Mr Bean]

I just use gasoline or kerosene. Cheap and effective.

[pivichot]

If you find orange iron oxide on aluminum, you've got deeper problems. Yes, it does oxidize but it doesn't turn rusty orange like an iron block will.


How long it takes depends on humidity. The wetter it is, the faster it'll happen. I wouldn't leave it more than a few hours though. Get your measurements and oil it again.

Ok. That'll be the plan for today.

[pivichot]

Actually, they do rust. That's why bare aluminum stuff usually comes heavily oiled. Once the oil is removed they rust/oxidize almost immediately, just the naked eye can't see it. Probably doesn't matter with engines but it sure does in the paint/pretreatment business.

I though they would corrode? Either way I have applied a coat of pb blaster to them once a week.

[pivichot]

Wouldn't gas leave a residue?

[Mr Bean]

Wouldn't gas leave a residue?

Depends what you are trying to do. It's great for removing oil and grease from parts. If you are gonna paint it after should probably wipe it with paint thinner or something else before hand.

[DerekTheGreat]

I though they would corrode? Either way I have applied a coat of pb blaster to them once a week.

You mean, 'wouldn't?' Bare, clean aluminum won't look rusty or even end up with that red "haze" that iron based stuff ends up with in short order. It can get scabby & blistery like iron based stuff but that takes a long time. Here in the pretreatment business aluminum is getting to be more common on cars but presents new challenges when trying to pretreat it before it goes into the paint shop. The scientists around here say a micro film of corrosion begins to develop the minute grease/protective layer is removed, this creates "mapping" issues with the pretreatment & ecoat that if left behind will become paint defects.