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Discussion Starter · #1 · (Edited)
I'm only asking because I've read lots of threads on several forums about the mighty task of removing heavy oxidation from aluminum motorcycle engines, and not one of them ever recommended or even mentioned spraying a degreaser/cleaner and then pressure washing. Bead blasting , yes but never pressure washing. Is there some problem with doing this?

My engine is removed and sitting on a stand, and the radiator, fan, carbs, and exterior wiring have been removed from the engine. All connectors and openings have been plugged and protected. My main problem is coming up with an efficient way of getting in all those recessed areas and corners, since the oxidation is heavy and I need to put some horsepower behind any cleaner I apply. A couple hours of using engine degreaser and scrubbing with abrasive pads has only succeeeded in cleaning up the flat easy areas, and done nothing for the corners etc.

Thoughts on the pressure washer?
 

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It is said that the strength of pressure washing will potentially harm gaskets. Those that do pressure wash engines either do it before a big rebuild or don't aim directly at the gasket. Some have recommended soda blasting.
 

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Discussion Starter · #3 ·
It is said that the strength of pressure washing will potentially harm gaskets. Those that do pressure wash engines either do it before a big rebuild or don't aim directly at the gasket. Some have recommended soda blasting.
I'm not so much worried about the gaskets, because I'm going to follow up the wash by taking the engine apart and replacing them all in the process, but I just don't want to hurt anything permanently in pressure washing it.
It has also occurred to me that Purple Power and a pressure washing may not be enough to knock down the oxidation...
 

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Oxidation is a chemical reaction the occurs to alum. so pressure washing wont do a thing.
Are you going to repaint or polish the engine?
Deburring wheel works good. Later.
 

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Pressure washing ANY engine falls into the category of "A really really bad idea". I was going to sell a car and kicked around the idea of cleaning up the engine and a good friend of mine who's an Airframe and Powerplant mechanic ("A&P") flat out said "don't you dare- the cold engine block against the hot steam of the washer will cause the block and parts to shift and the gaskets will then leak- don't do it". If you're going to take the engine apart anyway? Wait till you dissemble it, taking LOTS OF PICTURES so you know how to reassemble it, and then polish it until you're happy when you assemble it.
 

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Discussion Starter · #8 ·
get some aluminum brightener it will remove most of if not all the oxidized layer


i use anko bright and clean

The Right Aluminum Brightener for Tough Jobs - 800.545-2768

but napa and auto zone ect sell it to
LOL it appears Anko Bright N Clean is only available in 55gal drums. Hopefully I won't need that much!
Anko's "Citric" and "Phosphoric" aluminum brighteners are available in smaller quantities - does anyone have experience with those?
 

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The guys rebuilding the WWI truck use citric acid as a cleaner for the (surprisingly many) aluminum parts. They got theirs from a winemakers/homebrewer's supply. I'll be adding it to my bag of tricks as I also have quite a few things with corrosion on alloy parts.
 

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You could pressure wash it, but the real question is whether or not it will do anything. It's more likely to just knock off anything loose. Regarding the gaskets, probably no damage if they're in good shape, the rubber oil seals are another story. A direct shot could tear the rubber, even if it didn't the seals are designed to not only keep oil in, but dirt and dust out, not water at very high pressure. You would need to be tearing down the engine ASAP as after you were finished, it would almost certainly have water inside.
 

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this pressure washing theory thread is awesome

all i have to say is i have been using a pressure washer to clean my engines for 35 years no issues

i guess i just didnt read the manual lol

im off to wash some motors and bikes later
 

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It has also occurred to me that Purple Power and a pressure washing may not be enough to knock down the oxidation...
I'd be extremely cautious about using any industrial strength cleaners on aluminum, with or without using a pressure washer as they may actually INCREASE oxidation............

as the warning labels on aluminum "mag" wheels state:

"The use of any cleaning or polishing products not specifically formulated for aluminum may ruin the finish and increase oxidation, pitting, or discoloring. Severe damage may occur"
 

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tud i use purple power in a 50 percent solution as a degreaser and its awesome way more effective than simple green

in fact i use it in my ultrasonic cleaner to in 25 percent solution

but you are correct the wrong cleaner can permanently discolor the metal
 

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A long time ago I pressure washed my subaru engine. One month later the car would not start. Problem was the water got into and shorted a carburetor solenoid that was connected to the same fuse as the ignition. Took a long time to get home from work that night. I will never do that again.
 
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