handyandy

What is the difference between all of these motors? I'm just trying to learn some basics. Is there a significant difference in materials? I know forged is a very strong one. But what are some pros and cons? Can anyone compare them for me? Thanks you

handyandy

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bleau

Alum. is very light.
Cast Iron is stable but heavy. (most popular)
Forged like forged internals is a process of folding over the steel to make a shape. Very strong.

handyandy

Is aluminum less strong than cast iron? And is forged the heaviest?

bleau

Cast iron is probly the heaviest.
Depends on the application which one you would use.
Metrolgy is not my best subject.
Forged is a process of making shapes with steel.
Steel has iron and carbons and other things to in it to make it stroger.

If your talking something like a crankshaft then forged steel would be best a aluminum crank would break and a cast iron crank would bend and wear.
Hope this helps a little.

sweet99

The application certainly plays a major role. Now even plastics are coming into use as in the PI intake manifold. Plastics will come even more imnto use as the technology is advanced.
Forged is strong as it is formed from a single piece of material. So an engine with "forged internals" is a common phrase. This would mean the pistons and rods are forged but not always the crank in that particular phrase. These make the motor more able to take abuse and power.
Cast is made from a mold and is a 2 piece product in the sense it has a seam though it is often ground off.
Aluminum blocks are becoming more common and they require a steel sleeve to form the cylinder as aluminum would not hold up to the rigors the cylinder is subject to and would wear quickly. Just hang around and you will learn quickly as these are a good group of guys. mark

Triisomy21

Aluminum also flexes under high load applications. Meaning you have to have more girdles and stuff to help keep it from flexing. Do the big boys in drag racing use aluminum? Probably not but I cant be sure. Would the weight reduction be usefull in med. load applications? Yea.

Edit: Cast iron blocks can be counted on to maintain their integrity in high horsepower naturally aspirated, nitros and supercharged applications, and are even preferred by some hard core racers. For race or street the iron block does not come with the risk of block distortion that can be present in the lighter aluminum 4.6 blocks. This eliminates the issues that come with block distortion when trying to hold an engine together on the street or a long race season with out a rebuild.

The 4.6 aluminum blocks seen in Cobra from 96-98, rated at 305 horsepower, and 99/01, rated at 320 horsepower, and even the early Explorer 4.6 are effectively the same block. This block will work well for most street applications and can save the owner around 70 lbs of sprung weight. Lighter weight then the cast iron version they are prone to moving around, or distorting, when asked to produce big power. Later model Cobra cast iron blocks, 2003-04, rated at 390 horsepower, are significantly stronger and can be counted on for 700+ HP in their stock configuration with out the type of distortion seen in older aluminum block engines. These are modified Romeo blocks that have been clearanced to fit the extra center counterweights found on forged Cobra crankshafts.