Engine block aluminum vs compacted graphite iron CGI

All that has to do with the power train, gearbox, clutch, fuels and lubricants, etc. Generally the mechanical side of Formula One.
MadMax
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Re: Engine block aluminum vs compacted graphite iron CGI

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Honda Porsche fan wrote:
Sat Oct 29, 2022 2:28 pm
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 ?
Instead of constantly asking questions, how about doing some research and bringing some information to the discussion? You could go and have a look to see what things weight and do some comparisons.

Honda Porsche fan
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Re: Engine block aluminum vs compacted graphite iron CGI

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A Fatigue and Fracture Study on High Strength Cast Irons -

Abstract:
Fatigue strength and fracture of high strength cast irons, gray iron grade 300 and CGI grade 450, used for producing lightweight cylinder blocks, were studied. The results show endurance ratios of 0.27-0.28 and 0.38 for gray irons and CGI, respectively. The fracture surfaces in cast irons in general show the predominance of graphite and graphite/matrix interface; however, in CGI there is a larger proportion of fractured pearlitic matrix than in gray iron. This fact, and the differences in the morphology of the graphite/matrix interface, flat in gray iron, rough in CGI, explain the higher results of fatigue strength in CGI compared to gray iron.

Conclusions
Based on the experimental results, it can be concluded that:
- Gray iron grade 300 shows fatigue strength of 88 to 95 MPa, with an endurance ratio of 0.27-0.28,
while CGI grade 450 showed fatigue strength of 171 MPa, with an endurance ratio around 0.38.

https://www.scientific.net/MSF.925.296.pdf

Tommy Cookers
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Re: Engine block aluminum vs compacted graphite iron CGI

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useful source (and its bibliography)
though of course metallurgy not design

engine design choice (outside F1) will dictate which is the better material
eg many V6s have large cylinder pitch because of the chosen crankshaft design (eg SI or CI, 3x 2 pin throws or 6 throw)
large cylinder pitch disguised by the consequent large bore/small stroke
large cylinder pitch (unless CI) probably not needing strong block, crankshaft or bearing material

Europe followed the USA etc to 90 deg V6s - but 60 deg V6s came back ? eg Peugeot ? after 2 generations of the PRV

Honda Porsche fan
Honda Porsche fan
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Re: Engine block aluminum vs compacted graphite iron CGI

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Hoffman900 wrote:
Thu Oct 27, 2022 8:31 pm
Honda Porsche fan wrote:
Thu Oct 27, 2022 8:28 pm
Hoffman900 wrote:
Thu Oct 27, 2022 8:19 pm


No it wouldn't. CGI is not a new technology, it's been around for half a century. It's only used where the rules require it. You have nothing to back this up with and keep bringing up tensile strength as if they need more. Clearly they don't and you're ignoring about a dozen other considerations for material choice.



PVRS is a better solution than a Desmo type valvetrain. The Desmo valvetrain came about before PVRS. Del West proposed to NHRA a PVRS system for NHRA Pro Stock in the 1990s but NHRA rejected it despite builders being onboard. They didn't even bother asking NASCAR because they already knew the answer.

NASCAR engines were at about the limit and would be at the limit of what the pistons could withstand with no limit. They already had higher peak piston speeds than the 19,000rpm+ F1 engines. It would require allowing MMC pistons with no weight limit, and even then, it would eventually require less stroke. The biggest change they could do if they wanted to keep the architecture and rpm limit, but make the engines more powerful is get rid of that silly EFI system that was spec'ed, let me them go with a bespoke manifold actually designed for fuel injection, allow them to run MUCH higher fuel rail pressures (I think they're like 5.5bar, a blank sheet port injection design would be north of 200 bar these days) and put the injectors where they want. Both NASCAR and NHRA Pro Stock spec'ed fuel injection systems that are 1990s sophistication wise, but everyone has to run the same stuff, so it doesn't really change the show, but that's all a sidebar.
Would a 180 degree crank, dual overhead cams, gear drive cams, finger follower rocker arms and dual injection also help Nascar engines build more power ?

Maybe adopt a combo of Ford Coyote and Corvette C8R tech ?
180 crank won't hold together at those speeds at that displacement. Been tried many a time. The C8R does because RPM is capped.

DOHC, finger followers, 4 valves, absolutely, but why not just spec an Indy Car engine at that point?

The production Ford Coyotes and C8R are production based engines. Even with good tech features a bespoke purpose built 2 valve is going to make more power and last longer. Either one of those engines won't live 3000 miles spinning at 9000rpm. They weren't designed to do that. The GM, Toyota, and Ford blocks / heads were designed to be 1000bhp platforms and spin 10,000rpm and do so for over 500 miles. They're bullet proof now because they're making half that power.

There is nothing magical about naturally aspirated race engines. A Cosworth CA looks just like a whittled down DFV, a I4 Sportbike engine, a Honda I4, etc. all are pretty much the same. Some are just designed to survive longer at higher rpm (and that's the hard part), but it's extremely formulaic.
Can a cross-plane crank V8 rev higher than a 180 degree flat-plane crank with less vibration ?

gruntguru
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Re: Engine block aluminum vs compacted graphite iron CGI

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No and Yes.
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