Cast steel

General engine tech -- Drag Racing to Circle Track

Moderator: Team

Geoff2
Guru
Guru
Posts: 1980
Joined: Mon Nov 09, 2015 4:36 pm
Location: Australia

Re: Cast steel

Post by Geoff2 »

....plus alum is lighter & easier to machine...
Schurkey
HotPass
HotPass
Posts: 1858
Joined: Sun Mar 01, 2009 2:42 am
Location: The Seasonally Frozen Wastelands

Re: Cast steel

Post by Schurkey »

David Redszus wrote: Tue Mar 14, 2023 12:03 am
Little Mouse wrote: Sun Mar 12, 2023 9:20 pm I'm wondering why the OEMs or the aftermarket have not used cast steel to make cylinder block's or cylinder heads.
The primary reason being that ductile cast iron is a superior material, compared to steel,
for cylinder blocks.

Ductile, or nodular cast iron has graphite nodules that provide a low friction coefficient
when run against steel pistons rings. It also has a very high tensile, high hardness, is easy
to cast accurately and...it is cheaper than steel.
Far as I know, engine blocks are not cast from nodular iron--ductile iron, (nodules formed chemically by the metal alloy) or malleable iron (nodules formed by heat-treatment). The block casting is too complex. The thin sections cool too quickly, the thick sections cool too slowly. Nodular iron is used for smaller, simpler castings--connecting rods, crankshafts, steering knuckles, differential housings, etc.

https://en.wikipedia.org/wiki/Ductile_iron
https://en.wikipedia.org/wiki/Malleable_iron

The closest engine blocks get to "nodular" is Compacted Graphite.

Am I wrong?

Despite the fraudulent advertising of "cast steel" crankshafts, genuine steel is difficult to cast. "Cast steel" cranks are actually cast iron. Eagle finally admitted that their "cast steel" cranks have far too much carbon to classify as "steel", and GM has long acknowledged that "Armasteel" is pearlitic malleable iron--although I've heard folks claim it's melted-down WWII surplus steel armaments.
Last edited by Schurkey on Tue Mar 14, 2023 5:12 pm, edited 2 times in total.
Schurkey
HotPass
HotPass
Posts: 1858
Joined: Sun Mar 01, 2009 2:42 am
Location: The Seasonally Frozen Wastelands

Re: Cast steel

Post by Schurkey »

David Redszus wrote: Tue Mar 14, 2023 12:03 am Cylinder heads are made of aluminum alloys because it provides a high thermal transfer.
Geoff2 wrote: Tue Mar 14, 2023 1:08 am ....plus alum is lighter & easier to machine...
...and the molds are enormously easier/cheaper to make compared to molds for cast iron.
User avatar
modok
Guru
Guru
Posts: 3321
Joined: Sun Jun 06, 2010 1:50 am
Location:

Re: Cast steel

Post by modok »

Some aftermarket engine blocks are ductile iron.
You can tell from how it cuts, forming short chips rather than coarse dust.
Dave De
New Member
New Member
Posts: 9
Joined: Tue Jan 11, 2022 9:03 am
Location: Highland

Re: Cast steel

Post by Dave De »

Schurkey wrote: Tue Mar 14, 2023 5:06 pm
David Redszus wrote: Tue Mar 14, 2023 12:03 am
Little Mouse wrote: Sun Mar 12, 2023 9:20 pm I'm wondering why the OEMs or the aftermarket have not used cast steel to make cylinder block's or cylinder heads.
The primary reason being that ductile cast iron is a superior material, compared to steel,
for cylinder blocks.

Ductile, or nodular cast iron has graphite nodules that provide a low friction coefficient
when run against steel pistons rings. It also has a very high tensile, high hardness, is easy
to cast accurately and...it is cheaper than steel.
Far as I know, engine blocks are not cast from nodular iron--ductile iron, (nodules formed chemically by the metal alloy) or malleable iron (nodules formed by heat-treatment). The block casting is too complex. The thin sections cool too quickly, the thick sections cool too slowly. Nodular iron is used for smaller, simpler castings--connecting rods, crankshafts, steering knuckles, differential housings, etc.

https://en.wikipedia.org/wiki/Ductile_iron
https://en.wikipedia.org/wiki/Malleable_iron

The closest engine blocks get to "nodular" is Compacted Graphite.

Am I wrong?

Despite the fraudulent advertising of "cast steel" crankshafts, genuine steel is difficult to cast. "Cast steel" cranks are actually cast iron. Eagle finally admitted that their "cast steel" cranks have far too much carbon to classify as "steel", and GM has long acknowledged that "Armasteel" is pearlitic malleable iron--although I've heard folks claim it's melted-down WWII surplus steel armaments.
You are so right with this.
RAS
Pro
Pro
Posts: 304
Joined: Mon Jun 04, 2012 9:46 am
Location: Edmund Ok.

Re: Cast steel

Post by RAS »

mag2555 wrote: Mon Mar 13, 2023 11:41 am Take a look at the EMD 567 and 645 prime movers.
I think you mean the 710 casting. The 567 and 645 are normalized weldments. Adding 1" in stroke to the 645 got us the fuel efficiency we needed to compete with GE. We gave up that 1" with the port window used in the 2 event / cycle engine. My design. Adding 1" gave us a 10% increase in power with no increase in fuel consumption.
digger
Guru
Guru
Posts: 2722
Joined: Sun Jan 27, 2008 6:39 am
Location:

Re: Cast steel

Post by digger »

RAS wrote: Tue Mar 21, 2023 12:37 am
mag2555 wrote: Mon Mar 13, 2023 11:41 am Take a look at the EMD 567 and 645 prime movers.
I think you mean the 710 casting. The 567 and 645 are normalized weldments. Adding 1" in stroke to the 645 got us the fuel efficiency we needed to compete with GE. We gave up that 1" with the port window used in the 2 event / cycle engine. My design. Adding 1" gave us a 10% increase in power with no increase in fuel consumption.
710 blocks are also fabricated from wrought steel maybe the odd forging to
Post Reply