Engine block anodizing

[virgil]

Are alloy engine blocks and engine parts anodized as they leave the factory? If not is there any reason not to anodize a freshly cleaned block and heads before re-assembly? Got a place near me that can do it but should I?? or more to the point is there any reason NOT to??

Cheers,

Neil.

[jagracer]

Why would you want to?

[stevesingo]

Not all cast alloys can be anodised. IMO, I have never seen an anodised head/block on any engine, nor heard of it. I brighter folks than me don't think it is necessary, I won't question it.

Steve

[virgil]

jagracer said:

Why would you want to?

Purely for aesthetcis...some people paint them...I was just wondering if there was a good reason NOT to...

If some cast alloys cant be, then that could be a good reson why not too...


Cheers.

[GreenV8S]

virgil said:

jagracer said:

Why would you want to?

Purely for aesthetcis...some people paint them...I was just wondering if there was a good reason NOT to...

If some cast alloys cant be, then that could be a good reson why not too...


Cheers.

I've never seen an anodised engine and painting does seem pretty common, I suspect there is a good reason for that. I've never done anodising but from what I've seen it is relatively common on small components but much less so on large ones, so perhaps it's simply an issue of cost? I understand it's sensitive to the shape of the object and rather difficult to do concave shapes so that might also be an issue. Hopefully the people who are offering to do this understand it well enough to advise whether there are any technical reasons why it shouldn't / can't be done.

[eliot]

I dont think you can anodize rough cast ally. What about powder coating it?

[jwoffshore]

Motorbike frames come anodized from the factory - or at least it is some kind of thin hard coating, either clear or coloured, which prevents corrosion. The frames stand up to winter conditions fairly well, so the anodizing is quite effective.

The frames are usually a welded fabrication of many cast, extruded and stamped sheet parts. So, I guess it is possible to anodize castings under some circumstances.

[PhillipM]

Yes, it depends how much silicon/copper, etc are in the casting, most castings, even if you chemically remove the mucky top layer, will come out of an anodising bath a mucky grey colour with smutty black patches.

[hidetheelephants]

PhillipM said:

Yes, it depends how much silicon/copper, etc are in the casting, most castings, even if you chemically remove the mucky top layer, will come out of an anodising bath a mucky grey colour with smutty black patches.

This. You can do it, but it looks ste and because of the porosity it doesn't offer much corrosion resistance. Thus there's no point doing it.