Topic: Aluminum or Cast Iron

[Dan Furr]

Which is better ? I know the aluminum is lighter...............


                        The truck 4.8 and 5.3's are cast iron .....why?

[Sly Bob]

Not for much longer. With the mileage requirements going forward, all engines including the truck engines will be aluminum.

There was, in the past, the perception that the cast iron was better and the manufacturers continued to build cast iron engines on the same equipment that they have for years. Those plants and those processes are falling by the wayside as more technology and lighter materials are being incorporated into modern powertrains.

[Uranium-238]

In general, cast iron blocks are more durable and better if you want to make crazy power. Aluminum isn't as tough, more susceptible to issues after overheating, etc. In a truck, where weight isn't the primary concern, cast iron is usually the preferred choice. Many serious race engines are also cast iron.

[Dan Furr]

Thanks guys..............that's about what I figured..............but I needed to know..............

     I got away from car-fun for many years...........

     NOw my grandson has me loving cars again!

     But things have changed a lot , since the 60's.


     I had a family-car for 10 years in the eighties, put 120,000 miles on it,  and never raised the hood, not once!

  But my Solstice has cured that!...........


    

[JimmyBaja]

My '08 GMC truck I traded for the Sol had the 5.3L with a cast iron block but had aluminum heads - I guess maybe the best of both worlds.

[kennysabarese]

Someone else has made more power than you with the engine you are looking at getting. If they can make more than the power you want with aluminum, then your questions are answered.

[Rogue]

The cast iron blocks maintain their dimensional tolerances under stress much better than the aluminum. If you look at the serious high HP racers who use forced induction, CI is the runaway preferred material.

[snaponbob]

If you are considering a V8 swap, I would think that aluminum is the only way to go. ADDING power to a V8 Kappa is nearly useless, as USING the power already available in a V8 would be enough of a challenge !!!!  The weight penalty for a cast iron small block Chevy would be awful.

[Uranium-238]

If you are considering a V8 swap, I would think that aluminum is the only way to go. ADDING power to a V8 Kappa is nearly useless, as USING the power already available in a V8 would be enough of a challenge !!!!  The weight penalty for a cast iron small block Chevy would be awful.

Agreed. The only way you can justify a cast iron V8 in one of our cars is if you're making the car into an all-out dragster. (By all-out I'm implying a roll cage, tubbed rear wheels, racing transmission and gears, and so on.)

[werks]

Aluminum for sure!!!  The hey to going fast is power to weight!!!