Engine block aluminum vs compacted graphite iron CGI

[Hoffman900]

Per RET Issue 136’s deep dive dossier of the Audi R4 TFSI DTM engine uses a A356Cu alloy for the block and A201Ag alloy for the bedplate, and both are HIP processed.

Issue 100 has a deep dive on Audi’s diesel LMP engines and it was a similar design (though not explicitly stated in alloys).

Both the DTM and diesel LeMans engines are fuel limited, very high cylinder pressure, quick combustion concepts, not unlike the current F1 cars. Both use coated bores in leu of liners. The DTM engine runs an alloy piston where the LMP engine uses a steel piston.

The diesel engine is actually VERY similar to the current F1 engines (Miller Cycle, fuel limited / air abundant, variable blade turbo, hybrid, etc. The combustion concept is slightly different owing to the fact that F1 engines by rules have to be spark assisted).

As for billet heads and blocks, the cooling galleries need to be shaped / profile in such a way that a traditional billet simply won’t work. The cooling system is hyper critical in keeping these engines alive. I’m sure the castings are completely machined all over giving it a billet look, but you do that for weight reasons.

[Honda Porsche fan]

It seems compacted graphite iron CGI blocks, liners, crankcases, main bearing caps, flywheels, clutch components and bedplates have been used in race cars and production cars since the early 2000's...

https://www.competitiveproduction.com/a ... hite-iron/

[Hoffman900]

Per RET Issue 136’s deep dive dossier of the Audi R4 TFSI DTM engine uses a A356Cu alloy for the block and A201Ag alloy for the bedplate, and both are HIP processed.

Issue 100 has a deep dive on Audi’s diesel LMP engines and it was a similar design (though not explicitly stated in alloys).

Both the DTM and diesel LeMans engines are fuel limited, very high cylinder pressure, quick combustion concepts, not unlike the current F1 cars. Both use coated bores in leu of liners. The DTM engine runs an alloy piston where the LMP engine uses a steel piston.

The diesel engine is actually VERY similar to the current F1 engines (Miller Cycle, fuel limited / air abundant, variable blade turbo, hybrid, etc. The combustion concept is slightly different owing to the fact that F1 engines by rules have to be spark assisted).

As for billet heads and blocks, the cooling galleries need to be shaped / profile in such a way that a traditional billet simply won’t work. The cooling system is hyper critical in keeping these engines alive. I’m sure the castings are completely machined all over giving it a billet look, but you do that for weight reasons.

To add onto this, going back to the naturally aspirated era, the Cosworth CA’s heads and blocks were cast in Cosworth ‘Aluminum 01’, which is a proprietary alloy that is a derivative of A354 and casted by Grainger & Worrall. The cam carriers and covers are 7075 aluminum.

You can also get a taste of the Cosworth casting process here: https://www.giessereilexikon.com/en/fou ... 5beb5ce6e8

[Tommy Cookers]

so-called CGI seems to be a new genericised name for what was previously called nodular iron or ductile iron

ie CGI isn't fundamentally different from products previously associated with Meehanite
(though Meehanite was a licensed production system enabling a range of products)
Meehanite have nodular graphite product up to 180000 psi UTS and ADI to 230000 psi
interestingly to me the nodular has an outstanding elastic modulus 2.5 etc... (the usual steel being 2.1)

eg c.1960 Matchless/AJS stroked their sporty CI-crankshaft 600cc motorcycle to 650cc .....
the 650s constantly broke their crankshafts - until replaced with an identical version made from 'nodular' iron
famously the 'noddy' version could be rung like a bell

it seems that CGI is more a commercial phenomenon than a metallurgical one
the key point is that the Mg cored-wire inoculant is suited/intended for foundries using cupola furnaces
plus I guess carbon adjustability is a feature eg relative to scrap iron/steel ? additions

www.forums.thehomefoundry.org/index.php ... ndry.1513/
might be unlike most other information sources free of commercial influence

[MadMax]

so-called CGI seems to be a new genericised name for what was previously called nodular iron or ductile iron

Isn't it more the case that CGI is just a type of ductile iron as that is a term that covers a number of "flavours" of similarly modified iron.

[Honda Porsche fan]

so-called CGI seems to be a new genericised name for what was previously called nodular iron or ductile iron

ie CGI isn't fundamentally different from products previously associated with Meehanite
(though Meehanite was a licensed production system enabling a range of products)
Meehanite have nodular graphite product up to 180000 psi UTS and ADI to 230000 psi
interestingly to me the nodular has an outstanding elastic modulus 2.5 etc... (the usual steel being 2.1)

eg c.1960 Matchless/AJS stroked their sporty CI-crankshaft 600cc motorcycle to 650cc .....
the 650s constantly broke their crankshafts - until replaced with an identical version made from 'nodular' iron
famously the 'noddy' version could be rung like a bell

it seems that CGI is more a commercial phenomenon than a metallurgical one
the key point is that the Mg cored-wire inoculant is suited/intended for foundries using cupola furnaces
plus I guess carbon adjustability is a feature eg relative to scrap iron/steel ? additions

www.forums.thehomefoundry.org/index.php ... ndry.1513/
might be unlike most other information sources free of commercial influence

CGI has been used in production automobiles since the early 2000's. Also, every NASCAR engine block is CGI.

I wonder what F1 engines would be like if the blocks and heads were made out of it.

[MadMax]

CGI has been used in production automobiles since the early 2000's. Also, every NASCAR engine block is CGI.

I wonder what F1 engines would be like if the blocks and heads were made out of it.

A grey, probably dull, metal rather than grey, probably shinier, metal.

I'm still trying to figure out why you think F1 should use CGI rather than aluminium. Both have pluses and minuses and engineers will look at those and pick the combination that best fits their specific need. If they're using an aluminium alloy, it's because it's the best fit for their requirements.

[Hoffman900]

so-called CGI seems to be a new genericised name for what was previously called nodular iron or ductile iron

ie CGI isn't fundamentally different from products previously associated with Meehanite
(though Meehanite was a licensed production system enabling a range of products)
Meehanite have nodular graphite product up to 180000 psi UTS and ADI to 230000 psi
interestingly to me the nodular has an outstanding elastic modulus 2.5 etc... (the usual steel being 2.1)

eg c.1960 Matchless/AJS stroked their sporty CI-crankshaft 600cc motorcycle to 650cc .....
the 650s constantly broke their crankshafts - until replaced with an identical version made from 'nodular' iron
famously the 'noddy' version could be rung like a bell

it seems that CGI is more a commercial phenomenon than a metallurgical one
the key point is that the Mg cored-wire inoculant is suited/intended for foundries using cupola furnaces
plus I guess carbon adjustability is a feature eg relative to scrap iron/steel ? additions

www.forums.thehomefoundry.org/index.php ... ndry.1513/
might be unlike most other information sources free of commercial influence

CGI has been used in production automobiles since the early 2000's. Also, every NASCAR engine block is CGI.

I wonder what F1 engines would be like if the blocks and heads were made out of it.

NASCAR requires iron blocks. They absolutely do not use them for the heads. Ford has developed the RY45 for circle track and off road truck racers which is essentially the FR9, but with an aluminum block and can handle more bore / stroke (Super Modifieds are usually in the 43x-ish ci range). The RY45 is A357-T6.

All F1 engines would be, would just be heavier and likely create cooling difficulties. Also, aluminum is much more easily repairable.

That said, land speed builders like iron blocks from a bore stability standpoint, but they also typically need to add weight to get traction on the salt flats, so it’s not even a consideration for them. That said, an aluminum block with the high peak cylinder pressure concepts that are modern F1 engines and LMP diesel engines, when engineered properly, doesn’t have blowby issues.

[Honda Porsche fan]

so-called CGI seems to be a new genericised name for what was previously called nodular iron or ductile iron

ie CGI isn't fundamentally different from products previously associated with Meehanite
(though Meehanite was a licensed production system enabling a range of products)
Meehanite have nodular graphite product up to 180000 psi UTS and ADI to 230000 psi
interestingly to me the nodular has an outstanding elastic modulus 2.5 etc... (the usual steel being 2.1)

eg c.1960 Matchless/AJS stroked their sporty CI-crankshaft 600cc motorcycle to 650cc .....
the 650s constantly broke their crankshafts - until replaced with an identical version made from 'nodular' iron
famously the 'noddy' version could be rung like a bell

it seems that CGI is more a commercial phenomenon than a metallurgical one
the key point is that the Mg cored-wire inoculant is suited/intended for foundries using cupola furnaces
plus I guess carbon adjustability is a feature eg relative to scrap iron/steel ? additions

www.forums.thehomefoundry.org/index.php ... ndry.1513/
might be unlike most other information sources free of commercial influence

CGI has been used in production automobiles since the early 2000's. Also, every NASCAR engine block is CGI.

I wonder what F1 engines would be like if the blocks and heads were made out of it.

NASCAR requires iron blocks. They absolutely do not use them for the heads. Ford has developed the RY45 for circle track and off road truck racers which is essentially the FR9, but with an aluminum block and can handle more bore / stroke (Super Modifieds are usually in the 43x-ish ci range). The RY45 is A357-T6.

All F1 engines would be, would just be heavier and likely create cooling difficulties.

Automakers have proven that with the added strength of CGI the blocks can be made smaller and lighter than aluminum.

[Hoffman900]

CGI has been used in production automobiles since the early 2000's. Also, every NASCAR engine block is CGI.

I wonder what F1 engines would be like if the blocks and heads were made out of it.

NASCAR requires iron blocks. They absolutely do not use them for the heads. Ford has developed the RY45 for circle track and off road truck racers which is essentially the FR9, but with an aluminum block and can handle more bore / stroke (Super Modifieds are usually in the 43x-ish ci range). The RY45 is A357-T6.

All F1 engines would be, would just be heavier and likely create cooling difficulties.

Automakers have proven that with the added strength of CGI the blocks can be made smaller and lighter than aluminum.

False and if they did, the OEM race programs would be using it. I’m not really sure why you keep beating this horse… like what’s your agenda in continuing to ignore modern motorsports examples?

Besides size and weight, most motorsports programs are time constrained and aluminum is much more machinable, repairable, and quicker to make R&D changes on. It’s a win-win.

[dans79]

Automakers have proven that with the added strength of CGI the blocks can be made smaller and lighter than aluminum.

An F1 engine is in a different galaxy compared to the engine that's in your average persons car. It's all about the engineering!

[Honda Porsche fan]

NASCAR requires iron blocks. They absolutely do not use them for the heads. Ford has developed the RY45 for circle track and off road truck racers which is essentially the FR9, but with an aluminum block and can handle more bore / stroke (Super Modifieds are usually in the 43x-ish ci range). The RY45 is A357-T6.

All F1 engines would be, would just be heavier and likely create cooling difficulties.

Automakers have proven that with the added strength of CGI the blocks can be made smaller and lighter than aluminum.

False and if they did, the OEM race programs would be using it. I’m not really sure why you keep beating this horse… like what’s your agenda in continuing to ignore modern motorsports examples?

Besides size and weight, most motorsports programs are time constrained and aluminum is much more machinable, repairable, and quicker to make R&D changes on. It’s a win-win.

Not true. Every Nascar team uses CGI engine blocks and can go an entire season, over 15,000 miles on the same block...

NHRA Pro Stock teams also use CGI engine blocks...

"Nearly all NASCAR teams are running CGI engine blocks, or blocks with CGI liners. These liners are usually plated with a hard-surface coating. It has been reported that some NASCAR teams are able to run a whole season without having to re-bore the blocks."

"A recent 500cc Suzuki Grand Prix motorcycle engine had a crankcase fabricated from CGI. Nothing is put on these racing machines that would pose any kind of a weight penalty, and this is an extreme example showing the real potential of CGI applications."...


https://www.competitiveproduction.com/a ... hite-iron/

https://www.nhra.com/news/2020/what-che ... ock-engine

[Hoffman900]

Automakers have proven that with the added strength of CGI the blocks can be made smaller and lighter than aluminum.

False and if they did, the OEM race programs would be using it. I’m not really sure why you keep beating this horse… like what’s your agenda in continuing to ignore modern motorsports examples?

Besides size and weight, most motorsports programs are time constrained and aluminum is much more machinable, repairable, and quicker to make R&D changes on. It’s a win-win.

Not true. Every Nascar team uses CGI engine blocks and can go a entire season, over 15,000 miles on the same block...

"Nearly all NASCAR teams are running CGI engine blocks, or blocks with CGI liners. These liners are usually plated with a hard-surface coating. It has been reported that some NASCAR teams are able to run a whole season without having to re-bore the blocks."

"A recent 500cc Suzuki Grand Prix motorcycle engine had a crankcase fabricated from CGI. Nothing is put on these racing machines that would pose any kind of a weight penalty, and this is an extreme example showing the real potential of CGI applications."...


https://www.competitiveproduction.com/a ... hite-iron/

Same block, but serviced multiple times over that period. Again, NASCAR requires an iron block.

MotoGP hasn't used 500cc bikes since 2003. That's 19 years ago, soon to be 20. There is a reason it never caught on.

Digging around, here is something I put together for another site:

Honda NSX. 3.5L Turbo V6. 500hp from 6500-7500rpm, 405lb-ft from 2000-6000rpm. They mention a conventional iron bore sleeve would need 2.5mm (0.098in) between it and the water jacket. A 0.2mm (0.008in) Fe spray was applied, thus closing it up some. They now have 11mm (0.43in) in the bore bridge, including water jacket. 3.6in (91.4mm) bore size. This is a linerless block. All aluminum.

The Ford RY45 (large displacement, aluminum block developed by Roush Yates from the NASCAR FR9 for Late Model and off road trucks) has 4.500 (114.3mm) bore spacing and a max bore of 4.250" (107.95mm). My math shows it has a bore bridge of 0.250" (6.35mm) and no cooling jackets in them. So that would be a liner thickness of 0.125in (3.175mm). This engine in development, made 901hp @ 7500rpm and 692 ft-lbs at 6200rpm. 436ci and 14.5:1 compression. They found a peak of 135 bar was too high for the short block components they designed, so they tuned for an average pressure of 105 bar, noting it could be higher with more robust short block components. There was a package shared this summer of this platform that made 958hp @ 8500rpm and 657 lb-ft at 6600rpm. 438ci and 15:1 compression, so I can imagine peak cylinder pressures aren't too much higher than the test engine, just rpm has moved up.

The Audi R4 TFSI DTM engine makes > 570bhp from 6500-9000rpm, and 590bhp at peak. Boost limited to 3.5 bar and fuel flow limited to 90kg/hr. It is allowed a 100kg/hr fuel flow rate push to pass that boosts power to 644hp. The bore bridge has a distance of 9mm (0.35in) and a bore spacing of 97mm (3.89in) on a 88mm bore (3.46in). I don't believe there is a water jacket in the bridges, so this would result in a liner thickness of 4.5mm (0.177in). Because they run these engines at AFR of 16:1 to 20:1, they are built to be knock resistant. It seems they rule detonation as anything in excess of 300 bar, but these are over 200bar combustion events, maybe higher, seems to be a more realistic design number (just my guess). These engines are designed to go 4000 miles between rebuilds, have a 40.5-42% Brake Thermal Efficiency, and can "cope with more than 5000 severe (300 bar + ?) knock events before damage becomes a limiting factor" - Race Engine Technology, January 2022 issue. This is a linerless, A356Cu alloy block.

Here is the Honda F1 V6. Peak cylinder pressures well north of 200bar, but 1.6L V6 hybrid, fuel flow limited to 100kg/hr, making in excess of 1000hp peak. Even leaner afr to the Audi engine and need to be just as knock resistant. Brake Thermal Efficiency approaching 50% and have to go 1500 miles plus. They are also a structural component of the chassis in these cars. I don't know the alloy, but pictures show an aluminum block with a pressed(?) in liner.

The Audi LMP Diesel program also had an alloy block, with no liner, steel pistons, also a structural component of the chassis, and were also well north of 200 bar with rapid combustion (which is hard on parts).

As a comparison, the naturally aspirated V8s were just over 100bar peak cylinder pressure. The loads on these fuel limited, Miller Cycle, rapid combustion engines is very high and sharp.

As for iron blocks in NHRA Pro-Stock, NHRA requires cast blocks from OEM. It's been stated by builders themselves that a properly designed billet aluminum would work just as well, but NHRA won't allow it, so why even bother? The Audi LeMans engines are consuming 0.3L / 1000km of oil, so clearly the bores can be made to hold roundness when designed properly in aluminum, even at cylinder pressures well beyond NHRA Pro Stock (which would be just over 100 bar).

I'm really struggling to see why you are so vested in making this argument.

[Honda Porsche fan]

....

[Hoffman900]

I am comparing CGI to aluminum because that’s what NASCAR and Pro Stock have been using for nearly twenty years.

Do you have stock in CGI foundries? You keep bringing up tensile strength, but clearly none of the examples I have listed need that. If the bore can hold roundness at 250+ bar and is still lightweight,I don’t know what else you need. Cleary what they are using works. Not only the bore, but they can keep the aluminum bedplate attached to the block and they can keep the aluminum heads attached / sealed to the block as well at peak cylinder pressures more than double NASCAR and Pro Stock.

Best of luck to you convincing the motorsports they’re wrong.

I will also add those NASCAR blocks aren’t stressed at all. They’re 1000hp+ designs making nearly half that due to rules (induction / tapered spacer, compression, gear rule, etc)