Cleaning Aluminium Engine Parts

Hi I have used the normal home dishwasher ,obviously when she is not home, and I find that it is great ..TC

If you're short on time, solvent and or heavy duty cleaner used with appropriate brushes will be most effective. Obviously it also depends on the composition of the foreign matter one wants to remove. The heavy duty cleaners will remove 90%, but the other 10% can be a pain.
Time can be your friend if you've got some to spare: after removing most of the grime, let the parts soak in the chosen fluid(s) for a good while. Afterwards, spray them up close with a presser washer (be careful).

Sometimes more aggressive chemicals can be helpful. For rusted steel or iron parts, a soak in a pan of heated vinegar will take it off (do it outside!).
Aluminum can be treated with a solution of lye (again, outside).
These household chemicals can be quite dangerous if used improperly, so use due diligence. Also, they can be quite destructive on the parts being treated. I can tell you for a fact that lye will literally DISOLVE aluminum -as in the part is completely gone! (Don't ask how I know ).
Harsh chemicals are a drastic remedy and can dramatically alter the appearance of a part, often for the worse. Removing the chemical residues from treated parts is often more work than the original dirt would justify.
Also, when using chemicals it is most often necessary to post-treat with another chemical to neutralize the first treatment.

In my experience, some foreign matter will resist all manner of attempts at gentle removal. Parts subject to high temperatures in the presence of contaminants are some of the worst cases. Sometimes mechanical removal is the only remedy. If so, take into account the surface texture of the item to be cleaned. A rough sand cast surface can be cleaned with sand paper, but the cleaned area won't have the same texture any more; media blasting would be more appropriate in that case. Smooth surfaces are the easiest to clean with abrasives but it is usually impossible to obtain a match with the untouched areas - complete surface treatment will give the best results.

what does everyone use to clean their engines on a regular basis? (i'm not talking rebuild). i use my sr as a daily rider and the amount of grime that builds up in between the cooling fins etc is pretty amazing.

Something I've found that works great for cleaning between cylinder fins is an appropriately sized metal brush from a gun cleaning kit. I think 9mm is about right .

Aluminum can be treated with a solution of lye

Please be careful. Sodium hydroxide (Lye) reacts with aluminum metal to produce hydrogen gas in amounts that could be dangerous to the unwary. A lesser evil might be an Automotive Mag type cleaner containing phosphoric acid or a commercial aluminum brightener containing the same. There are several to choose from. On a related note, I think it is better to clean early and often before the oil and dirt have an opportunity to bake into place.

PC

Some (most?) aluminum parts have a laquer or polyurethane coating on them to prevent oxidization. Forks come to mind, as well as aluminum cases. Be extra careful when using abrasive cleaners, such as brillo pads or the like, when cleaning these parts because the coating can be scraped off. some harsh chemical detergents or solvents can harm the coating as well. Always try a small area out of view when experimenting with new cleaning techniques.

in the old days we'd wet the bike & use TSP tri sodium phosphate (with a little brush) & rinse off, (on the engine only)