Carbon Block?

[n smikle]

The carbon engine If allowed, will still fit the bill of minium weight and COG rules if you put your engine ballast in the right locations. E.G the boss of the output shaft, and anywhere along the min cog plane. Your radius of gyration will be significantly reduced while keeping a very high level of stiffness.

The V8 engine is already the second stiffest component of modern F1 cars, really needs no additional stiffening (especially in light of the new V6's) and so I see a CFRP block's purpose as a way to enhance balance and handling.

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http://www.tohotenaxamerica.com/


Composite Castings LLC (CC) announces the launch of its new, lightweight, carbon fiber composite, 4-cylinder engine blocks. This novel engine block design was developed by Matti Holtzberg, President and founder of Composite Castings, based in West Palm Beach, Florida, USA. Extensive research resulted in the selection of Toho Tenax America's Tenax® brand carbon fiber as the reinforcement for the base epoxy resin.

The resulting high performance compound is molded into the finished engine block profile using CC.s proprietary molding process (patented and patent pending) that uses low cost tooling and provides for faster cycle times compared to conventional CFRP molding methods.

The new engine blocks are 45-50% lighter in weight than a comparable aluminum block. The weight saving is a significant competitive advantage in the performance engine business and will attract a lot of interest from the worldwide automotive industry where weight is so critical, particularly in hybrid cars. A composite block is cast to a net shape, which: eliminates secondary machining; significantly reduces NVH due to the relationship between fiber and resin; does not corrode; and represents a huge reduction in its carbon footprint because there is no metal to melt.

Also, in comparison to die casting, the tool cost is 50% less and the tool life is 5-10 times greater. The first block that CC is casting for the performance engine market is an after-market specialty engine, which can be an alternate to the popular Ford Duratec/Mazda MZR inline 4. The carbon fiber composite block weighs 20# (9.1 kilos) LESS than the stock alloy block.

Looking further forward, an entire range of 4- and 8- cylinder engine blocks is planned for motorsports as well as OEM automotive, truck and marine applications.

kutch,

That engine block is not really a "carbon fiber" block. It would be more accurate to characterize it as a carbon fiber-filled epoxy resin block. I believe the carbon fibers used are very short and discontinuous. They simply provide improved creep strength for the epoxy resin matrix.

Aluminum F1 engine blocks are incredibly light and stiff. An F1 engine block made using this particular composite construction would not be much lighter, and possibly even less stiff in some respects, since the matrix is still epoxy resin.

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[Edis]

http://www.tohotenaxamerica.com/


Composite Castings LLC (CC) announces the launch of its new, lightweight, carbon fiber composite, 4-cylinder engine blocks. This novel engine block design was developed by Matti Holtzberg, President and founder of Composite Castings, based in West Palm Beach, Florida, USA. Extensive research resulted in the selection of Toho Tenax America's Tenax® brand carbon fiber as the reinforcement for the base epoxy resin.

The resulting high performance compound is molded into the finished engine block profile using CC.s proprietary molding process (patented and patent pending) that uses low cost tooling and provides for faster cycle times compared to conventional CFRP molding methods.

The new engine blocks are 45-50% lighter in weight than a comparable aluminum block. The weight saving is a significant competitive advantage in the performance engine business and will attract a lot of interest from the worldwide automotive industry where weight is so critical, particularly in hybrid cars. A composite block is cast to a net shape, which: eliminates secondary machining; significantly reduces NVH due to the relationship between fiber and resin; does not corrode; and represents a huge reduction in its carbon footprint because there is no metal to melt.

Also, in comparison to die casting, the tool cost is 50% less and the tool life is 5-10 times greater. The first block that CC is casting for the performance engine market is an after-market specialty engine, which can be an alternate to the popular Ford Duratec/Mazda MZR inline 4. The carbon fiber composite block weighs 20# (9.1 kilos) LESS than the stock alloy block.

Looking further forward, an entire range of 4- and 8- cylinder engine blocks is planned for motorsports as well as OEM automotive, truck and marine applications.

kutch,

That engine block is not really a "carbon fiber" block. It would be more accurate to characterize it as a carbon fiber-filled epoxy resin block. I believe the carbon fibers used are very short and discontinuous. They simply provide improved creep strength for the epoxy resin matrix.

Aluminum F1 engine blocks are incredibly light and stiff. An F1 engine block made using this particular composite construction would not be much lighter, and possibly even less stiff in some respects, since the matrix is still epoxy resin.

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CF reinforced high temperature polymers like polyetheretherketone and polyamide-imide can be useful for some components in engines where the part have to have a large volume due to geometric dimensions, but I would not chose such a material for an engine block where strength and stiffness is critical. CF reinfored PEEK or PAI can withstand temperatures up to about 250-275 degC and can handle engine oil, but their strengh is just about 100-200 MPa at room temperature and their stiffness is just 10-20 GPa. A cast aluminium alloy like 319 T5 (common in engine blocks) is twice the density, but it's stiffness is four to eight times better, and it's strength is about 200 MPa (77 MPa at 10^8 cycles). At about 100-150 degC I think aluminum comes out even better, and it is far far cheaper than the reinforced polymers. Compacted graphite iron at about 450 MPa is another option to aluminum suitable for production blocks (about 2.5 times the density and strength of aluminum but fatigue strength is much better).

If an engine block should be made out of a composite material I would rather look into Al/SiC. Silicon carbide will boost aluminums strength and stiffness (particulary its stiffness) without increasing its density, the finished block would also conduct heat well and it will offer a good wear resistance. With enough SiC it's probably possible to run the pistons directly in the block which will give a stiff and compact block.

For racing engines direct metal laser sintering could offer an interresting choice for engine blocks and cylinder heads. Aluminum alloys, titanium alloys, maraging steel, high temperature nickel and cobalt alloys and others can be formed into very complex parts with very thin walls if required. Single parts or small series can be made fast without high tool costs. Perhaps one possebility to make a composite block is to make a 'skeleton' with cylinders and main bearings by direct metal laser sintering in for instance titanium and the outer part of the block like the crankcase in CFRP, similar to BMW's Al/Mg composite block.

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Edis,

I agree that only thermoplastics (polyimide/polyamides) or BMI (bismaleimide) would provide suitable Tg and creep strength for use in a cylinder block. I also agree that a more practical approach for production blocks is the Al/Mg composite used by BMW.

MMC's like Al/SiC are useful for cylinder liners. But MMC's are a bear to machine due to the carbide whiskers. MMC's must be machined by grinding or using diamond tooling.

A better material for cylinder liners is FRA: http://tritonsys.com/products/bearingliners.html It is light, strong, high modulus, highly wear resistant, has good thermal conductivity, has good corrosion resistance, and machines readily.

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