Engine block aluminum vs compacted graphite iron CGI

[cheeRS]

The Corvette C8R raced in IMSA and raced at the 24 Hours of Le Mans and Rolex Daytona, are those production based engines and if so how do they get them to last ?

A short stroke for a V8 (3.15in) and a rpm limit dictated by the restrictor and rules that keep piston speeds down. Going back to the bore thing, this means the engine can’t really be any bigger than 5.5L. It would never survive at its factory delivered rpm limit for a 24hr race.

A NASCAR Cup engine has a 3.25in stroke and the rpm they run at, a 180* crank would shake the entire thing apart. I know third hand of a Pro Stock team who tried one in the late 90s and it didn’t get very far.

The Ford Voodoo 180 crank had a 3.7xin stroke and had all sorts of warranty issues from the vibrations and they stopped making it.

The 180* crank doesn’t really make more peak power, but can help with the power curve shape. It also helps with pulling on the ACO mandated restrictors easier.

Does a large displacement V4, V6, V10, V12 with a 180 crank suffer the same vibration issues as the 90 degree V8 ?

Can a 6.0 liter V10 with a 180 crank rev higher than a 6.0 liter V8 with a 180 crank ?

In general, all other things being the same, yes. The V8 is going to have bigger pistons or more stroke vs the V10, which means more intertia -> more stress -> lower RPM breaking point.

The most recent v10 close to 6L that I can remember is the 5.7L unit used in the Carrera GT. Dodge had (has?) a giant 8.4L v10, but that's about as far away from a 180* flat plane as you can get.

[johnny comelately]

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.

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.

My point is about engine life and how long can aluminum race engine blocks go before rebuilds vs CGI blocks. If a CGI block can last a whole season I think that saves the teams a lot of money in the long run.

I'm not disagreeing with you on the performance of aluminum for one or two races, I'm focusing on the longevity of the aluminum.

I'd rather have a CGI block that can last a whole season, have more power if that means it has to be slightly heavier than a aluminum block. CGI is much lighter than grey cast iron.

Hello HondaPorsche fan,
Could you list all of the properties of CGI that you consider would be appropriate for race engines ( what if blocks and heads were integral?)
Are you aware of the (old) problem with iron, and I know that is not CGI, versus aluminium with combustion in regards to preignition and acoustics?
I appreciate your enthuisiasm

[dans79]

At what liter does a 180 degree crank become a liability? 5.0 liter? 5.5 liter ? 6 liter ?

I'm not sure why you think any decision related to a high end racing engine can be narrowed down to one or two deciding factors, but i can assure you if maximum performance is your goal, you will be considering dozens of different factors.

[Martin Keene]

Because a F1 engine is a stressed member cast iron cracks

Cast iron blocks are used a stressed members as well, in tractors of all things!

[Martin Keene]

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

True CGI is different to SGI and has benefits, but the only company that sells, or used to sell ~5 years ago, the kit to be able to produce CGI sold it with a huge royalty attached to it, so very few foundries bothered with it.

[Martin Keene]

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.

A lot heavier than they are today out of aluminium. Whilst it is true you can make a block lighter in CGI than normal GI or SGI, you can only make it lighter because it is stronger than GI or SGI.

The density of CGI is very similar to that of GI & SGI at ~7850Kg^m3, where as aluminium is ~2750Kg/m^3.

A CGI block and head would be significantly heavier than an aluminium one.

[Martin Keene]

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.

Source? I work for an engine manufacturer and I have not seen a CGI block that is lighter than an aluminium one.

CGI was developed to enable truck manufacturers to push up the power of existing engine platforms beyond the capability of their existing block by improving the strength, with the added advantage you can use the same tooling.

[Tommy Cookers]

.... it seems that CGI is more a commercial phenomenon .....

True CGI is different to SGI and has benefits, but the only company that sells, or used to sell ~5 years ago, the kit to be able to produce CGI sold it with a huge royalty attached to it, so very few foundries bothered with it.

captured so I have this good info to hand ....

[Honda Porsche fan]

Because a F1 engine is a stressed member cast iron cracks

Cast iron blocks are used a stressed members as well, in tractors of all things!

The Ferrari F50 uses a cast iron block as a stressed member because aluminum was not strong enough. Why didn't they go with an aluminum block? It was not strong enough.

Which road cars or high performance sports cars use aluminum as a stressed member and how much does it cost and how long does it last long term compared to using grey cast iron or compacted graphite iron CGI ?

I'd like to see the long term results of street racers and drag racers using the Toyota Supra and Dodge Viper iron blocks vs if they were to use aluminum blocks. Some of these cars are producing over 2,000 hp with twin turbo on repeated runs.

[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.

Source? I work for an engine manufacturer and I have not seen a CGI block that is lighter than an aluminium one.

CGI was developed to enable truck manufacturers to push up the power of existing engine platforms beyond the capability of their existing block by improving the strength, with the added advantage you can use the same tooling.

The 2015 Ford F150 has part of it's engine made out of CGI for added strength as has many automakers that have been using CGI in it's vehicles since the early to mid 2000's.

CGI engine weight reduction...

@ 3:00 in the video below he explains the size and weight savings of CGI vs aluminum between a Mercedes 3.0L aluminum V6 vs a Audi 3.0L CGI V6...




Far more fatigue resistant than Aluminum in higher temperatures. Due to CGI's high strength, it can technically be machined to be lighter than aluminum while maintaining the same strength levels (although generally, CGI blocks are not machined this far in order to keep strength levels high).18 july 2018

[Honda Porsche fan]

If Nascar teams were allowed to use aluminum engine blocks instead of CGI would they choose to ? Or would they stick to CGI blocks ? Would the aluminum blocks last as long as the CGI blocks that can currently last over 15,000 miles an entire season without any cracks and don't need to be re-bored ?

Before anyone answers, I'd like to see and hear what Doug Yates at Roush/Yates Ford Racing and those working at Hendrick Motorsports' engine department have to say.

[Honda Porsche fan]

....

[Tommy Cookers]

the subject of the thread declared at the start ....

Engine block material - aluminum vs compacted graphite iron CGI for Formula 1 ?

the SinterCast man says .....
CGI blocks are heavier than al alloy blocks ...

and the minimum cast CGI thickness is 3 mm
(so how much waste weight is there in the iron engine ? - just in the water jacketing)

60 years ago ....
Ford USA cast some production (iron) 260 smallblock engines in alloy (identical dimensionally) - without problems
(no it wouldn't work on a 357 (same cylinder pitch) - isn't Nascar a generic 350ish smallblock ?)
Jaguar did the same (iron design cast in alloy) for 3 litre GT class blocks - but the main bearing webs failed

[Honda Porsche fan]

How much more specifically would a F1 and Indycar engine weigh if the block and head were made out of CGI?

Would that weight increase be so much more that the race car with the CGI would lap slower than the car with the aluminum block and heads even if the car with CGI had more horsepower and torque? What would the lap times be with the car with CGI engine parts ? It's all hypothetical.

How much more horsepower and torque would the F1 and Indycar CGI engine need to make to offset the weight increase of the engine to lap equally or faster than the car with the aluminum block and heads ?

Would Nascar race cars with aluminum engine blocks produce quicker lap times than they currently do with CGI blocks ? What would the lap times be at each specific race track ?

[Martin Keene]

the subject of the thread declared at the start ....

Engine block material - aluminum vs compacted graphite iron CGI for Formula 1 ?

the SinterCast man says .....
CGI blocks are heavier than al alloy blocks ...

and the minimum cast CGI thickness is 3 mm
(so how much waste weight is there in the iron engine ? - just in the water jacketing)

60 years ago ....
Ford USA cast some production (iron) 260 smallblock engines in alloy (identical dimensionally) - without problems
(no it wouldn't work on a 357 (same cylinder pitch) - isn't Nascar a generic 350ish smallblock ?)
Jaguar did the same (iron design cast in alloy) for 3 litre GT class blocks - but the main bearing webs failed

Sintercast, that's the company. They basically invented CGI and are the only company that sell the control equipment to produce CGI. If they say CGI is heavier than aluminium, then it is heavier than aluminium. But most of already knew that.