alengyel

I thought it was Alusil...........

adrial

I am 600% sure that our blocks are Alusil.

nick_968

Definately Alusil!!

DHC8FO

Kolbenschmidt SK lists the 944 as Alusil. For alot of info on the process check out http://www.bmwseven.com/index.html It's pretty in depth.

-Mark

DHC8FO

Sorry forgot to tell you click on "Reconditioning of Aluminum Engines"

Voith

bump

Any new-ish info on this?

Own Goal

eh, used to work part time as a teen in an automotive machine shop. The std. vat for doing cast iron blocks and heads had a large amount of caustic soda. It will dissolve aluminum. More than a few times had some guys try and cheat the owner out of a clean up and he would come in early on Monday morning and open the vat (left out back cooking)to fetch a string of rods less pistons! Auto machine shops will use the right type vat but it's not the same as the good old fashioned ones for cast iron. Few years ago actually made a vat with a 55 gal drum and a burner from a hot water heater. I was rebuilding some machinery. The mix was available from National ChemSearch. probably long gone and this was early days of MSDS etc. Don't go that route.

kev951

you can hot tank aluminum but no higher than 180 degrees Fahrenheit for no longer than 50-60 minutes,and only with detergent compatible with aluminum, otherwise it will oxidize the surface and look like a rusted old block, thats all, so just punch out all the oil plugs when hot tanking, and if it does oxidize, you can soda blast , bead blast, or wire wheel , to clean and re tank for less duration and temp, then blow dry and coat with wd40 or similar and bag her, painting the block is pointless , especially on a race or track car, concours, is different and an entire different world and lifestyle, then only thing thats really ok to paint is the cam tower . You want everything to dissipate heat faster and covering it up slows it down. same goes for the oil pan and intake. Leaving a blasted or natural finish and putting a clear is ok, but you guys can do whatever you want And our blocks are all alusil lined bores unless sleeves are installed by an engine builder or machine shop.

Chris White

“Hot Tank” is a very general label for a cleaning process. Some of the chemicals used for cleaning iron blocks will damage Alusil blocks (they do a great job dissolving cam bearings in an iron block!). Some other chemicals are fine. A lot of lot of shops have switched to a less caustic chemical that is aluminum friendly.

The old fashion way is just a vat of hot chemicals. The modem way is an ultra-sonic cleaning bath with less caustic chemicals.

The best way is baking soda blasting after an ultra-sonic bath.

I think the nicest final finish is wire brushing the casting after cleaning, the alusil will have a nice shiny finish and it is very easy to clean and you can ‘touch up’ the finish with a wire brush anytime. I have yet to see a powder coating that stays looking nice after hard use.

Euro951

I had a machine shop "hot tank" my bare block with no problems. I did however thoroughly wash the block with a solution of laundry detergent and water after the hot tanking process. I always go over my blocks/ cylinder heads after hot tanking with bottle brushes and detergent / water mix as a final measure before assembley.

No problems with stock bore on my alusil block, rings seated fine.

Own Goal

All good info and lots of options out there. Probably the max best clean of aluminum is IF ( big if and don't count on it) you know someone that does commercial anodizing. The prebath is very effective at cleaning and etching aluminum. But, it's the opposite of the hot caustic soda vat; it destroys Fe based metals. Most commercial platters won't do this since unless you really protect and find all the steel inserts (silicone works) it will foul their batch. Many years ago our company did a lot of work with aluminum extruder / anodizer and talked them into doing some motorcycle engine parts for me. Even with extreme care I had to replace one valve seat.

Fishey

Its an Alusil bore...

Also, you can do about anything you want to it and your not going to hurt it..

Alittle hot water and soap isn't going to hurt the bores. Hell, I have put plenty of them through tumble media (cleaning) and have had zero problems out of the engines with now over 10,000mi.

Chris White

Most Anodizing places I know do not want anything to do with automotive parts! Its way to easy to contaminate their process with oil/dirt/grease. If they do mil spec anodizing they require that the initial part be as clean as a new part.

Darwantae951

Hey Own Goal,

I know of a pretty good plater in Ft. Worth that did a lot of my small stuff before I left. If you ever want their info, let me know. They had a flat rate of $30 up to 100lb and then it went up after that.

Own Goal

Chris, like I said; we did a LOT of business with that company and the parts were very clean and still had to get the pres to tell his anodizing plant mgr. to do this. In retrospect; a bad idea but thought I would mention. Last year I bought a kit from Causwell (Carswell?) to do black oxide on some machine parts at work. Also tried some zinc chromate look alikes for myself. Small parts plating is way more accessible than used to be but after finished put it away. The whole OSHA, MSDS etc. stuff for a business is problematic. We are an OSHCON participant so don't need any "off the map" process going on. When did my own short block just sent it out to a trusted machine shop. I cheated.
Modded: would that be the place that does lots of bike stuff in stock yards area?