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Sat Aug 27, 2005 12:16 pm

What is the best way to clean the aluminum engine block..I'm not talk half way I'm talkin a really good clean?

Sat Aug 27, 2005 12:38 pm

I was astonished this week to follow some advice I saw in multiple places - the magnesium/Al case cleans up VERY well with just soap and water. I cleaned the inside of my 40 with a mild brush, scotch pad and soapy water and the black build up came right off.

Sat Aug 27, 2005 12:44 pm

I thought that dilute muratic acid sounded like a good idea.(engine was out of car). WRONG! Reaction with magnesium caused a lot of sparks :shock: but it did not break into full flame. Fortunately fire extinguiser was nearby.

Sat Aug 27, 2005 3:38 pm

Unless you have an aftermarket alum case or a type 4 case it is not aluminum. It is a magnesium alloy.

I have used "purple power" or castrol "super clean" (more expensive) for years. Just do not let it fully dry on the case... use it...scrub... rinse... repeat...repeatedly until clean... spray with WD or other spray lube between sessions if you cannot finish the job and when done rinse well and spray it again with the WD to keep any residiual from etching and to keep it from corroding until you are ready for the final cleaning before assembly.

Sat Aug 27, 2005 5:44 pm

How about removing paint from the engine block?

PO painted the case black, probably looked good when he first did it, but now it is only in places...

Sat Aug 27, 2005 9:51 pm

last time I wanted to get paint off a block I got some paint stripper (gasket remover spray is about the same too) and let it sit, but not for very long. Then it was off to the coin-op car wash and blast the case.
I've found that in general, a high pressure washer usually cleans cases pretty well. just want to make to blow out the passenges afterward so no mineral deposit "scum" forms from the water as it dries.

andy

Mon Aug 29, 2005 11:37 am

OVERHAULIN67 wrote: What is the best way to clean the aluminum engine block..I'm not talk half way I'm talkin a really good clean?

Castrol Superclean works pretty good. If you can get a like substance in bulk, you can dip the case for a few days. Rinse, repeat.

Otherwise, a brush a mineral spirits will get it clean. If you wanna go ALL out, take it to a machine shop, or engine shop with a glass bead blaster. It'll get it clean enough to pass as brand new.

-kf

Mon Aug 29, 2005 1:30 pm

How good do you want it to look?
I had mine soda blasted. I will have it hot tanked at the machine shop and Dow 7 coated prior to reassembly. I expect it to look new.

Mon Aug 29, 2005 3:59 pm

Steve22 wrote: How about removing paint from the engine block?

PO painted the case black, probably looked good when he first did it, but now it is only in places... \

Purple power/Super Clean in a large tub over night will eat that paint right off. Then stick the case in soapy water, plain water and blow dry. You can pickup the Purple power concentrate from Home Depot for around $25 for 5 gallons. I mix it 1 part purple to 3 parts water for cases

Sat Feb 28, 2015 7:10 pm

Is purple power ok with the aluminum block? Ive heard horror stories of it eating away at aluminum :S

Sun Mar 01, 2015 7:02 am

I went to a Porsche Concours Tech session many years ago and they resurrected a grungy 356 motor using the following procedure:

- Run engine until hot.
- Shut down and disconnect battery
- Cover and tape all electrical parts with plastic and tape
- Liberally apply kerosene with stiff paint brush
- Let sit for several minutes
- Hose off with water
- Restart motor and drive until dry

Kerosene will not affect the paint and leave the magnesium or aluminum with a shiny patina.

While this is not the most ecologically friendly method, it definitely works. I've done is several times to the bottom of my 914 engine prior to a concours event.

Dave

Sun Mar 01, 2015 7:50 am

bad idea to glass bead or abrasive blast! that stuff goes in places you'll never get it out and it will find its way right into your new bearings. I used kerosene and a parts scrubber brush. clean out all oil passageways with test tube brush. when you think its good enough... repeat.

Sun Mar 01, 2015 10:35 am

dcheek wrote: I went to a Porsche Concours Tech session many years ago and they resurrected a grungy 356 motor using the following procedure:

- Run engine until hot.
- Shut down and disconnect battery
- Cover and tape all electrical parts with plastic and tape
- Liberally apply kerosene with stiff paint brush
- Let sit for several minutes
- Hose off with water
- Restart motor and drive until dry

Kerosene will not affect the paint and leave the magnesium or aluminum with a shiny patina.

While this is not the most ecologically friendly method, it definitely works. I've done is several times to the bottom of my 914 engine prior to a concours event.

Dave

That's exactly how we cleaned our 3,350 cu. in double row eighteen cylinder radial engines in the navy., only we used a fire hose to wash them down afterwards. On the underside ( topside is always wiped down and clean ) of my VW's I use the same, but rinse with a pressure washer while the engine is running. To clean a shortblock before tear down I use ZEPP with a stiff brush done very quickly and a pressure washer right away. Keep ZEPP away from your hands/ always wear rubber gloves as it eats flesh. Never let it stay on the case for more than five minutes, it eats that too., but it really removes grease and oil. ZEPP is water soluble. NEVER buy round up or any other type of weed spray, just dilute ZEPP to 1/2 strength and have at the weeds and ants just disappear and never come out of their ant hills again.
If you use a hot tank be careful as it will eat a case and heads up in no time and None of this 1/2 day to 24 hr. stuff like we do on domestic cast iron blocks and heads.

Sun Mar 01, 2015 12:55 pm

On our aircraft engines we used to submerge them in gunk. Great stuff! Open all the oil galleys, soak for day or so, then rinse with water.

Sun Mar 01, 2015 2:21 pm

Soda blasting is the best, backing soda also dissolves in water.

Still need to clean oil passages

Sun Mar 01, 2015 2:23 pm

Dry ice blasting might work well too