Engine block aluminum vs compacted graphite iron CGI

[MadMax]

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]

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]

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

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]

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]

No and Yes.

[Tommy Cookers]

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

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

yes correcting myself .....

both Europe and Japan followed the USA to 90 deg V6s
both then went in the 1990s to (6 throw) 60 deg - now avoiding large cylinder pitch by having some 'thin' throws etc etc
60 deg being the more compact angle for transverse engine installations

[FW17]

Can they make the cylinder and piston like this and avoid the rings?

[etusch]

Can they make the cylinder and piston like this and avoid the rings?

https://m.youtube.com/watch?v=feGrx29XR4Q

heat, friction, oiling, cost.

[gruntguru]

When you start burning stuff on top of the piston it gets hot, grows and doesn't fit the cylinder any more.+

[FW17]

Won't the cylinder expand too?

[etusch]

Won't the cylinder expand too?

Do you think it will expand only outward of the center point of cylinder ?

[Dr. Acula]

Won't the cylinder expand too?

It will, but the piston gets a lot hotter, especially when the piston moves to the lower part of the stroke. The cylinderwalls aren't that hot lower down, though the piston more or less keeps its temperature.

[Aleena]

Hi guys
The choice between engine block aluminum and compacted graphite iron (CGI) depends on various factors, such as engine design, cost, weight, and performance requirements.

[saviour stivala]

There was a time when they went down to using just 'ONE' piston ring in 'for qualifying only engines' when that was permitted. But that was another different subject. But having said all that, material chose is firstly out of the question as what is to be used is dictated by the rules, and secondly, as long as there is no chose of material to use as well as long that there being the need of lubricating oil to be used there is going to be no chance of 'ZERO CLEARANCES'.

[Hoffman900]

There was a time when they went down to using just 'ONE' piston ring in 'for qualifying only engines' when that was permitted. But that was another different subject. But having said all that, material chose is firstly out of the question as what is to be used is dictated by the rules, and secondly, as long as there is no chose of material to use as well as long that there being the need of lubricating oil to be used there is going to be no chance of 'ZERO CLEARANCES'.

That was short lived. What to gain in losing friction you lose in blow by. Even NHRA Pro-Stock engines are running 3 rings.

They all also went back to heavier wrist pins when they realized lighter ones flexed and caused ring land deformation.