machine shop cleaning up the engine

[Pamela H.]

The old process was Hot Tank but, the most current stuff I've seen about machine shops degreasing motors coming in to be rebuilt leads me to believe that they are baking the blocks at high temps and shot peening to chip off rust, scale and baked on crud. Wouldn't this alter the "As Cast" finish on an OE block. Any comments, suggestions, how has anyone dealt with this IF we were to Judge the car somewhere down the road?

[Clem Z.]

Re: machine shop cleaning up the engine

The old process was Hot Tank but, the most current stuff I've seen about machine shops degreasing motors coming in to be rebuilt leads me to believe that they are baking the blocks at high temps and shot peening to chip off rust, scale and baked on crud. Wouldn't this alter the "As Cast" finish on an OE block. Any comments, suggestions, how has anyone dealt with this IF we were to Judge the car somewhere down the road?

maybe not the as cast part but the stamp pad surface could change from the bead blasting unless they protect it before blasting. the as cast part will be covered with paint. the caustic they used before to "boil" the block is a hazardous material and cost a lot to dispose. remember the govt is looking out for our well being.

[Bruce B.]

Re: machine shop cleaning up the engine

Pamela,
Most cast iron parts are painted so the "as cast" does not apply.
I believe "as cast usually applies to aluminum parts such as valve covers, intake manifolds, etc.

[Stephen B.]

Re: machine shop cleaning up the engine

I have taken blocks and heads to a chemical stripper in Cincinnati that typically strips metal body's. The advantage to this process is that the water jackets get cleaned out. Facility's like this go under different names and can be located in your area by looking in Hemmings Motor News under services. It worked for me, any thoughts?
Stephen Barrett (21558)
59,66,71,73

[Edward J.]

Re: machine shop cleaning up the engine

The old process was Hot Tank but, the most current stuff I've seen about machine shops degreasing motors coming in to be rebuilt leads me to believe that they are baking the blocks at high temps and shot peening to chip off rust, scale and baked on crud. Wouldn't this alter the "As Cast" finish on an OE block. Any comments, suggestions, how has anyone dealt with this IF we were to Judge the car somewhere down the road?

Pamela,I recently had my engine done and most of the machine shops are using a citrus based solution which genreally reqiures a longer time in the tanks. and will removed most of the paint and grease on the engines, but it is not as good as the older caustic solutions.

[Duke W.]

Re: machine shop cleaning up the engine

The most important thing is to knock out deposits in the cooling passages. Try to find a shop that has an ultrsonic cleaning tank.

Duke

[John M.]

Re: machine shop cleaning up the engine

We've had a couple of them baked and shot peened and we put a piece of agle iron over the pad and bolted it in place with one of the water pump bolt holes. The blocks are very clean inside and out. The pad looks like new but a little darker.
JB McRae 30025