Let's Talk About CGI (Compacted Graphite Iron)

[A70TTR]

thats definitely the question I'm most curious about, but yeah I'd be surprised if BMW used the new engine. they already said they aren't even considering an 'M' variant due to projections and niche, and the B58 will easily do decent power and doesn't need that tunability.

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[SupraStew85]

Fascinating - that the engine isn't a B58 derivative. I am very curious to know whether the B58 will be offered in the A90 at all, and whether the "3JZ/8M/BJZ whatever" will be offered in the Z4

I already have headgasket ptsd thinking about it being called an 8m .

 

[A70TTR]

 

[MA617M]

7M THE WORLD

 

[A70TTR]

to the bottom of the Toyota AU sales list Ryley goes

 

[MA617M]

someone's gotta do it

 

[supraboi]

Toyota rumored to give the BMW B58 engine a CGI (compacted graphite iron) engine block

Have you ever heard of CGI engine blocks? You are not alone. It means the block is made out of compacted graphite iron which offers properties that are stronger than aluminum but lighter than iron. The application of CGI blocks is gaining popularity with diesel motors.

A rumor floating around is that Toyota will design an iron block for their B58 I6 turbo variant going into the MKV Supra. Now, that is likely false. What is getting lost somewhere in the translation is that the block could be CGI.

Now, this is a rumor so do not get too excited but it would definitely set the Supra apart. Assuming the rumors built on snippets from Toyota engineers are true that would mean the B58 could take a hell of a lot of boost. This would be a nod to the MKIV Supra and its practically legendary tuning reputation which Toyota is obviously aware of.

It would also mean BMW B58 owners would not have to sleeve their own aluminum block or necessarily reinforce it if going for big power. Toyota already did all the work and they could simply swap to the factory CGI block which would be superior.

Taking this even further it would mean S58 owners (next gen G80 M3) would have an off the shelf block solution as well should they go chasing huge power figures.

Will it happen? Only Toyota and BMW know that. If it does, the MKV Supra will indeed be special.

This brings us to one of the newer, more exotic iron alloys, compacted graphite iron (CGI). This new type of cast iron was invented back in 1949, about the same time ductile cast iron as discovered. For many years, nothing much came of CGI because it was not quite as strong as ductile iron. But it was 75 percent stronger and up to 75 percent stiffer than gray cast iron. This meant an engine block could be made up to 20 percent lighter than a standard gray cast iron block – a perfect solution for reducing weight or making a block stronger to handle more horsepower.

Though still much heavier than aluminum, CGI has five times the fatigue resistance of aluminum at elevated temperatures, and twice the resistance to metal fatigue as gray cast iron. When used in a diesel engine or a racing engine, it can provide a significant savings in weight.

Many Caterpillar engine components are being switched to CGI, such as modular heads, and Audi is using CGI in their 2.7L, 3.0L V6 and 4.0L V8 diesel engine blocks. The BMW Series 7 V8 engine is also CGI. Even Hyundai is now producing some CGI blocks (2007 Veracruz).

One aftermarket supplier of engine blocks said CGI is a good upgrade for performance applications where high levels of nitrous oxide or turbo boost are being used. The added strength provided by CGI has no weight penalty, but typically adds about 40 percent to the cost of the block over gray cast iron.

Machining CGI is a little more difficult than gray cast iron because of the increased hardness of the material. Coated CBN works well, but tool wear is accelerated and feed rates may have to be slowed to achieve the same surface finish.

https://www.bimmerboost.com/showthr...e5c63eb7605243e8273782656&p=803243#post803243

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