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Engine Cleaning

bluehole

Active member
What do you folks recommend for cleaning the engine? I have read about bead blasting, but I don't need to do that at this stage. I would just like to clean it up a bit. I am thinking of a solvent (WD-40...Gunk?) and brush or steel wool?
 
Harbor freight... lots of throw away brushes: they sell 6 for 2.99 or something like that..
Nitrile gloves at harbor freight too...
Kerosene: a gallon of it.
Lots of rags
a large catch pan; I use an industrial baking pan about 18"X20"
Scotch Brite pads..
Scrub, and wipe down with kerosene soaked rag..
Scrub wipe down
Scrub wipe down.


Back when I did this, I lucked out: Home Depot had a box of 4 WD-40 cans for 10$, so it was easy to clear away the excess grime by spraying it and letting it drip off the engine.
 
My first choice would be soda blasting it but other than that, I'd stick to a brass bristle brush.

Scotch Brite pads are impregnated with an aluminium oxide abrasive and by using them you will certainly be changing the nature of the finish of your engines cases. Some guys don't care as long as the cases are shiny but I can spot SB'd cases a mile away

I've had great success by using a stiff brass brush. I smear some metal polish onto the surface I'm working on and then, while pressing it firmly into the surface, I move the brush in a circular manner until the "grain" of the casting gets cleaned out.

My method takes some time and elbow grease but it works pretty well and leaves the factory finish intact.

I do this once a year to the entire bike and after that I just ride the thing. My bike looks good but it'll never look new again and I wouldn't want it to!
 
Last edited:
harbor freight... Lots of throw away brushes: They sell 6 for 2.99 or something like that..
Nitrile gloves at harbor freight too...
Kerosene: A gallon of it.
Lots of rags
a large catch pan; i use an industrial baking pan about 18"x20"
scotch brite pads..
Scrub, and wipe down with kerosene soaked rag..
Scrub wipe down
scrub wipe down.


Back when i did this, i lucked out: Home depot had a box of 4 wd-40 cans for 10$, so it was easy to clear away the excess grime by spraying it and letting it drip off the engine.


+1
 
I'm one for Simple Green and elbow grease (with scotch brite pads, tooth brushes and metal brushes).

You can use Eagle One Mag wheel cleaner (found at most auto parts stores) but:
A - wear gloves. it will try to etch your skin
B - it will clean your engine but also eat away whatever surface BMW leaves on their case... leaving exposed aluminum that will either need to be re-painted or cleaned often.

Re-painting the case isn't as bad as you'd think. There are plenty of high heat paints that work great on these old machines.
 
I've also used Eagle One.

+1, maybe 2, on the nitrile glove recommendation; it's aggressive stuff. And as Josh mentioned, it will etch into the castings requiring more, continual work later on...

If it's really heavy I'd start with an application of GUNK engine cleaner, or diesel fuel. Following that I prefer old-school powdered detergents, mix with hot water to a paste-like consistency and worked with an old-fashioned nylon-bristled automotive parts cleaning brush. Most detergents generate some heat when mixed this way and that aids cutting grease.

Spic'n'Span a good one. Not as fast as "aluminum cleaners" but more controllable, and you can mix it with diesel fuel. The detergent won't dissolve, but becomes a "grit" to help the diesel fuel cut the dirt. Just have to watch out where you do all this... diesel and GUNK both love to eat asphalt. Not to mention where the run off goes. I live near the ocean so I always put down heavy gauge visqueen to work on.

PCB.jpg
 
B - it will clean your engine but also eat away whatever surface BMW leaves on their case... leaving exposed aluminum that will either need to be re-painted or cleaned often.

Re-painting the case isn't as bad as you'd think. There are plenty of high heat paints that work great on these old machines.
The airhead engine cases are not painted. Some of the timing case covers, valve covers and starter covers are painted black, but Type 247 engines all came from the factory in as-cast aluminum. I don't believe BMW started painting engine cases until the oilheads in '93 -- maybe the K-bike cases in '83, but I don't believe so.

As far as cleaning often, it's a matter of exposure. Ride in a salty environment, clean often. Ride only occassionally and in decent weather, and you can go for years. I cleaned the case on my wife's R75/5 a decade ago, finishing with a WD-40 wipe down, and I haven't needed to go back in since then.
 
Thanks for your help guys. I went at it this morning with a bit of nearly all that was suggested. I kind of like/don't mind that old look on my /5 so I ended up using Eagle 1 and a soft brush on most of the engine. That took away most of the heavy greasy dirty grit without drastically changing the finish. I brought in the Scotchbrite pads and WD-40 in some stubborn places. I am happy with the results.

Cosmetically, my bike is a long term project. I decided going all out on the engine would look out of place at this time. As things come together I may opt for the "full clean". I appreciate your help. She looks so much better.
 
I use Formula 88 found at Advanced Discount Auto Parts. It comes in a gray bottle. Spray it on let set for 5 min or so and warsh off with water. You may need to apply it several time for heavy grease.
 
What do you folks recommend for cleaning the engine?

Is it dirty or is it corroded? Which one will determine what cleaning products are to be used.

I'd never use an abrasive pad or harsh chemicals to clean dirt, if that is the case. Especially if the engine cases are still protected by what I think is a clear anodized finish (later models...my 1990 GS for example)

I use Swish Facto AT30; have been since 1986. It is a water based degreaser sold by Swish-Kenco in the US. It is all I use on my cars and motorcycles.
 
what I think is a clear anodized finish (later models...my 1990 GS for example)

.

Are you sure about this? Anodizing is not a surface "plating" process. Anodizing changes the surface through an electrolytic process which changes the natural oxyde layer of the part. It is called "anodizing", becasue the part represents the "anode" in the process. Anodization changes the microscopic texture of the surface and changes the crystal structure of the metal near the surface. On aluminum it usually provides a shiny surface.
 
Are you sure about this?

No, since I have not seen it published anywhere except on forums, and info on forums isn't always accurate.


Anodizing is not a surface "plating" process.

I know. I am familiar with the process. Great for corrosion. Not so great against abrasion.


On aluminum it usually provides a shiny surface.

Which is what the factory surfaces of my 1990 R100 GS are, on the day I bought it back then and presently. And they are still not corroded.
 
For cleaning oil and grease, I like plain Gunk GP mixed with kerosene.

Spray off with hose - cover carbs, etc.

To make old aluminum look like new - now that's another matter.
 
For cleaning oil and grease, I like plain Gunk GP mixed with kerosene.

I use that when I buy a neglected used vehicle with years of thick caked on crud.

Its hard on pavement though, so I usually let a garden hose stream under my vehicle to keep the Gunk/kerosene from eating away at it.

All other times I use Facto AT30, a water based degreaser used in the transportation sector.
 
Brooks Reams has quite a few samples of what he did in his restoration of his r75/5.


http://brook.reams.me/about/bmw-mot...1-bmw-r755-cylinder-cleanup-and-head-rebuild/

http://brook.reams.me/about/bmw-mot...project/23-bmw-r755-transmission-refinishing/

http://brook.reams.me/about/bmw-mot...d-project/33-bmw-r755-rear-drive-refinishing/



He cleans the parts using "AutoSol" aluminum cleaner with scotchbrite pads, then "00" steel wool with more autosol aluminum cleaner until he gets a nice luster, and then finally using a bit of autosol aluminum polishing paste for a little bit of shine, and with an aluminum protectant oil at the end to keep it from corroding again.


Hah, this sounds like an autosol commercial. hahaha. I havnt used this stuff but I gotta say I really like the look of the cases after using this method (at least from photos).


An awesome custom BMW builder here in SoCal Brandon Mungai also uses what I guess is a similar method of engine case cleaning/polishing as well. www.bmwcaferacer.com
 
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