Compacted Graphite Block

[CcanDo]

Compacted Graphite blocks are said to be up to 50% stronger than Iron blocks. CG is said to compete with Aluminum Wt., subject to machining. The bore should easily go 4.60, initial, and have a long life thereafter. There should be a balance between reduced Wt. and rigidity.

The OEM Auto industry is said to be taking a hard look at CG for their engines.

Would a freshened CG engine be more desirable than either iron or aluminum, all other things being equal ?

[bustedbrick]

CGI (Compacted Graphite Iron) requires very specialized (and patented) castings process and the part must be designed for the material.

You're right it is lighter and stronger than grey cast iron that all our BB's use, but its going to take some serious $$$ to commercialize it for the comparatively small volumes left for BBC.

[CcanDo]

Originally Posted by bustedbrick

CGI (Compacted Graphite Iron) requires very specialized (and patented) castings process and the part must be designed for the material.

You're right it is lighter and stronger than grey cast iron that all our BB's use, but its going to take some serious $$$ to commercialize it for the comparatively small volumes left for BBC.

Thanks for your thoughts, do you, including, anyone else, feel there is significant value added, using CGI ? We realize 4.60 bore is commonplace in grey iron. However, CGI should offer a safety factor.

Further, if the OEM's cause the modern method to be CGI, then grey iron could be rationalized as obsolete.

[Pismo10]

Pure graphite would be the best. No need to cool it even..

[CcanDo]

Originally Posted by Pismo10

Pure graphite would be the best. No need to cool it even..

First time read, your post was considered humor. However, perhaps you would care to expound, please !!

[Pismo10]

Originally Posted by CcanDo

First time read, your post was considered humor. However, perhaps you would care to expound, please !!

Well the block would be fine uncooled if it were pure graphite which is tough to burn/melt, but everything else would be a puddle of liquid so it really is unrealistic humor. Maybe all parts could be made of pure graphite? Then there may be structural issues.

[bustedbrick]

Originally Posted by CcanDo

Thanks for your thoughts, do you, including, anyone else, feel there is significant value added, using CGI ? We realize 4.60 bore is commonplace in grey iron. However, CGI should offer a safety factor.

It's a great engine block material, hence its adoption for diesel engine blocks and heads which have higher duty cycles and loads than normal gas engines. The problem is $$$ and experience with the material (how will rings seat to it, etc. etc.) that hasn't been developed yet for gasoline engines (diesels use separate liners).

As universal as the BBC is, it's architecture is inadequate for high HP marine applications IMHO. Investing in CGI wouldn't have a good payback.

[CcanDo]

Dart reports, they are using Compacted Graphite in a race, small block Ford. One customer broke a rod, normally that failure would have poked a hole in the block. However, all that happened was to scratch the pan rail.

Nothing was said regarding rings seating.

Dart also claims core shift doesn't exist with their finished blocks, because the block is sonic tested before machining starts.

[CcanDo]

Who has an opinion of how much difference there could be in cylinder bore round, CGI vs. grey Iron.

[Planetwarmer]

You could just use a sail. They dont need cooling, and they are lighter than CG blocks.