No such thing as forged steel engine blocks?

[Howard]

They have forged aluminum blocks, why not forged steel blocks?

 

[NikPreviousAcct]

Why would you need an engine block that heavy? Come to think of it, Aluminum gets a hell of a lot more maliable at lower temperatures than steel does.


yeah... why DON'T we have forged steel engine blocks?

 

[Howard]

Cast iron is just as heavy.

 

[geno]

They have cast iron blocks, how does cast iron hold up in comparison to steel? (I know steel is stronger so...)

 

[Howard]

Well, I'd say cast iron is pretty durable...

 

[NikPreviousAcct]

Originally posted by: Howard
Cast iron is just as heavy.

Cast iron is just as heavy as a metal that's refined beyond the point of being cast iron? Ain't there something wrong with that?

 

[geno]

Originally posted by: Howard
Well, I'd say cast iron is pretty durable...

Yeah, there's a lot of motors being pushed very far with either cast iron/aluminum blocks, I doubt blocks are the weakest link in the equation.... I could be wrong tho, it's been known to happen in the past

 

[Analog]

cast aluminum is brittle, thus it needs to be forged if under stress.

Forged iron blocks would be very expensive and not necessary. Cast iron is cheap to make and perfectly suitable to machining and holding up to the stresses of the engine.

When I was a coop at GM, we were using cast iron crank shafts in our diesel V8s used in cars. They began to crack in service all over the country, so GM decided to go with a forged crank at higher cost, but better reliability. Cast cranks were used in gas engines, but the gas engines had much lower compression, and less stress on the crank. The diesel engine (as you know) has much higher compression than gas, thus has greater stress on the crank. The whole V8 diesel was an engineering disaster because it was a gas engine converted to diesel, thus these kind of problems crept up everywhere. Finally GM threw the design out and went with a clean sheet to design a V6 diesel that worked well.

 

[Transition]

The blocks may be aluminum, but the sleeves are always some form of steel.

 

[Analog]

Originally posted by: Transition
The blocks may be aluminum, but the sleeves are always some form of steel.

absolutely, you don't want to wear steel on aluminum!

 

[Howard]

Originally posted by: yellowfiero

Originally posted by: Transition
The blocks may be aluminum, but the sleeves are always some form of steel.

absolutely, you don't want to wear steel on aluminum!

That does not make sense. He says the liners are always some kind of steel, and you agree and say that doesn't work?

 

[Howard]

Anyway, there need not be any type of liner unless both pistons and block are aluminum. If they are, they can be iron coated (like what they did with the Chevy Vega). Or, they can coat the cylinders with iron (never heard of it being done with steel), or Nikasil (nickel silicon carbide), or FRM (Fiber-Reinforced Metal), which is a fiber-based sleeve reinforced by poured aluminum and then machined to desired specs.

 

[Linflas]

Originally posted by: yellowfiero

Originally posted by: Transition
The blocks may be aluminum, but the sleeves are always some form of steel.

absolutely, you don't want to wear steel on aluminum!

IIRC GM gave that a shot in the 70's with the Chevrolet Vega. Needless to say it did not work very well. :Q

 

[Zenmervolt]

Originally posted by: Howard

Originally posted by: yellowfiero

Originally posted by: Transition
The blocks may be aluminum, but the sleeves are always some form of steel.

absolutely, you don't want to wear steel on aluminum!

That does not make sense. He says the liners are always some kind of steel, and you agree and say that doesn't work?

No, he's saying that it does work. The sleeves go between the steel and aluminum parts, with the sleeve fixed against the aluminum. This way the moving steel part wears against the non-moving steel liner, and not against the aluminum part. Steel wearing against aluminum would wear the aluminum out quickly.

ZV

EDIT:

Nikasil (nickel silicon carbide)

I thought that Nikasil was Nickle, Aluminum, and Silicon?

 

[Howard]

Sorry, I didn't realize he was talking about steel pistons.

Fastar than yuo! Linflas!

 

[Howard]

Text

The Nikasil coating used in our cylinders is a nickel and silicon carbide matrix coating about 0.07mm (.0025-.003") thick. The nickel matrix is very hard, but it is comparatively ductile, whereas chrome is brittle. Dispersed through the nickel are particles of silicon carbide less than 4 microns in size. These extremely hard particles make up 4% of the coating and form a multitude of adhesion spots on which oil can collect. Beside providing a very long wearing surface for the piston and rings, the silicon carbide particles also contribute to longer engine life by ensuring good cylinder lubrication

 

[Linflas]

Originally posted by: Howard
Sorry, I didn't realize he was talking about steel pistons.

Fastar than yuo! Linflas!

Heh I had a friend in high school that had one of those Vegas his parents bought brand new. Only took 30k miles for the black smoke to appear.

 

[Howard]

So, no forged steel blocks because there's no need for them?

 

[Zenmervolt]

Originally posted by: Howard
Text

The Nikasil coating used in our cylinders is a nickel and silicon carbide matrix coating about 0.07mm (.0025-.003") thick. The nickel matrix is very hard, but it is comparatively ductile, whereas chrome is brittle. Dispersed through the nickel are particles of silicon carbide less than 4 microns in size. These extremely hard particles make up 4% of the coating and form a multitude of adhesion spots on which oil can collect. Beside providing a very long wearing surface for the piston and rings, the silicon carbide particles also contribute to longer engine life by ensuring good cylinder lubrication

You're right. Cool, I learned something.

ZV

 

[Howard]

Anyway, I still have not figured out what nickle is.

 

[woodie1]

Originally posted by: Howard
So, no forged steel blocks because there's no need for them?

I think you have it right.

 

[Zenmervolt]

Originally posted by: Howard
Anyway, I still have not figured out what nickle is.

It's a lot like nickel, only spelt wrong. (I noticed it after I posted and just didn't care.)

ZV

 

[Howard]

Originally posted by: Zenmervolt

Originally posted by: Howard
Anyway, I still have not figured out what nickle is.

It's a lot like nickel, only spelt wrong.

ZV

Better work on that past tense stuff, too.

 

[Zenmervolt]

Originally posted by: Howard

Originally posted by: Zenmervolt

Originally posted by: Howard
Anyway, I still have not figured out what nickle is.

It's a lot like nickel, only spelt wrong.

ZV

Better work on that past tense stuff, too.

Spelt. It's about halfway down the page and the second entry for "spelt". I'm just a sucker for those archaic words.

ZV

 

[Howard]

I understand the use of spelt, it's just that there was a nice piece of ** on my monitor that blocked the slash on the t. So I thought you typed "spell".