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Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 20 Apr 2023, 20:39
by saviour stivala
The 'one piston ring' engines were called qualifying engine only. The only thing that prevented them running in that configuration in the race distance was oil consumption.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 21 Apr 2023, 15:17
by Hoffman900
saviour stivala wrote: ↑20 Apr 2023, 20:39
The 'one piston ring' engines were called qualifying engine only. The only thing that prevented them running in that configuration in the race distance was oil consumption.
I know and you missed my entire point.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 21 Apr 2023, 15:51
by saviour stivala
I can't figure up what point/s of yours I missed. Maybe you will explain. Leaving aside the Piston-pins issues the other racing categories you said run into, this because I never came upon such issues being encountered in F1, Running the F1 engines with just one piston ring blow-by was never mentioned as a problem encountered. could be that crankcase oil/air scavenging in F1 was good enough to cope with the extra blow-by.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 28 Apr 2023, 20:55
by etusch
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 21 Sep 2023, 00:57
by Setitup
Honda Porsche fan wrote: ↑29 Oct 2022, 04:56
Martin Keene wrote: ↑28 Oct 2022, 12:53
johnny comelately wrote: ↑24 Oct 2022, 20:20
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.
The viper is an all aluminum block
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 08 Oct 2023, 20:41
by Alex077
gruntguru wrote: ↑23 Dec 2022, 00:34
When you start burning stuff on top of the piston it gets hot, grows and doesn't fit the cylinder any more.+
Absolutely,
when combustion residues accumulate on top of the piston, the heat generated causes expansion. This can lead to a situation where the piston no longer fits properly within the cylinder, resulting in reduced engine efficiency and potentially severe damage if left unaddressed.
GB whatsapp Apk
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 09 Oct 2023, 19:45
by AR3-GP
saviour stivala wrote: ↑20 Apr 2023, 20:39
The 'one piston ring' engines were called qualifying engine only. The only thing that prevented them running in that configuration in the race distance was oil consumption.
That would have been desirable from '14-'17
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 10 Oct 2023, 07:17
by saviour stivala
AR3-GP wrote: ↑09 Oct 2023, 19:45
saviour stivala wrote: ↑20 Apr 2023, 20:39
The 'one piston ring' engines were called qualifying engine only. The only thing that prevented them running in that configuration in the race distance was oil consumption.
That would have been desirable from '14-'17
If interested in the more detailed technical maters please refer to ''Qualifying 'only' specials (engine) - Gptechnical page 1 of 26 Sept 2019 05:34.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 24 Dec 2023, 01:57
by coaster
Would anybody have a thread link to a discussion about iron main caps on alloy blocks?
Chevy LS uses this, has this arrangement ever being problematic?
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 24 Dec 2023, 05:58
by Greg Locock
You can make a stab at that knowing the coefficient of expansion of the metals and the oil temp, which is unlikely to exceed 150 deg C.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 24 Dec 2023, 19:46
by Tommy Cookers
coaster wrote: ↑24 Dec 2023, 01:57
.... iron main caps on alloy blocks ....Chevy LS uses this, has this arrangement ever being problematic?
well ....
billet LS blocks are made from 6061 alloy ....
unlike the usual cast block alloy (357) it has little silicon and so has greater coefficient of expansion
390 alloy (for pistons) has very high silicon content and so unusually low expansion - but isn't used for blocks
presumably GM knew what they were doing
these lowish coefficients of expansion increase a lot with temperature
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 30 Dec 2023, 16:33
by Martin Keene
coaster wrote: ↑24 Dec 2023, 01:57
Would anybody have a thread link to a discussion about iron main caps on alloy blocks?
Chevy LS uses this, has this arrangement ever being problematic?
I would imagine every road car aluminium engine block uses iron main caps, aluminium is just not going to provide the durability against the combustion loads. What are you thinking might be the problem with this arrangement?
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 30 Dec 2023, 19:41
by coaster
I often see turbo versions splitting the block along the line of the main bolts, i cant help but wonder if a heat differential played small part in the failure as one fights the other with expansion the bolt line becomes the weak point.
The Ferrari F40 turbo engine uses alloy main caps with only 2 bolts, this kind of failure is unheard of, but then we are talking turbos so whoever controls the wastegate is going to be failure point really, I guess.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 31 Dec 2023, 03:37
by Rodak
Tommy Cookers wrote: ↑24 Dec 2023, 19:46
coaster wrote: ↑24 Dec 2023, 01:57
.... iron main caps on alloy blocks ....Chevy LS uses this, has this arrangement ever being problematic?
well ....
billet LS blocks are made from 6061 alloy ....
unlike the usual cast block alloy (357) it has little silicon and so has greater coefficient of expansion
390 alloy (for pistons) has very high silicon content and so unusually low expansion - but isn't used for blocks
presumably GM knew what they were doing
these lowish coefficients of expansion increase a lot with temperature
Well, I'm curious about the claim of the coefficient changing 'a lot' with temperature. Everything I see agrees that it's not linear and does increase with temperature although the changes are minor; we're dealing with pretty low temperatures in an internal combustion engine. Do you have a source for this? I'd appreciate a reference.
Re: Engine block aluminum vs compacted graphite iron CGI
Posted: 31 Dec 2023, 05:55
by Greg Locock
There are step changes in density when solids go through a phase change, which would give a very non linear COTE, I find it hard to believe this is an issue for blocks, heads, or pistons.