Aluminum vs Iron Block

[gmyeah]

So, what's the big difference between an aluminum and iron block. Is it just weight, better fuel mileage? Is it built to last longer. Just curious....since I noticed that was yet another option.

[jro909]

iron blocks were built for heavier applications or harder work...as they can take a bigger beating but they weigh more

 

aluminu blocks now a days are right about on par with iron blocks and will be the norm soon enough

[Quint]

With today's alloys, the only difference between a stock aluminum engine block and a stock iron one is weight.

[1990ss]

Aluminum blocks warm up a lot faster in the winter. That's one thing I like about it.

[dewfpo]

Aluminum blocks warm up a lot faster in the winter. That's one thing I like about it.

 

 

By the same token, then shed heat faster as well.

 

DEWFPO

[wtbrowne]

Weight is the enemy of economy, performance and handling. The aluminum block is lighter than cast iron and just as durable for most applications. You won't be seeing cast iron in many engine applications in the future. It is, in fact, nearly extinct now in most car engines.

[fbachman]

i believe AL blocks have sleeves in the cylinders that are non-Al. Doesn't mean it's better or worse---just is.

 

Over the years, most manufacturers have learned how to do AL blocks pretty darn well.

 

For trucks, my guess is the weight savings is king and the prime motivator for an AL block.

[crepitus]

AL block burn oil iron do not. Thats what i have gathered from this forum

[00Silverado4x4]

AL block burn oil iron do not. Thats what i have gathered from this forum

 

 

Not 100% true as I have a cast iron block & mine burns a little oil...although it's more age/mileage (90k+ miles) related vs design...

[Ryan00TJ]

Weight is the enemy of economy, performance and handling. The aluminum block is lighter than cast iron and just as durable for most applications. You won't be seeing cast iron in many engine applications in the future. It is, in fact, nearly extinct now in most car engines.

 

 

I agree. My LY5 is an iron block that has no problems save for weight. Aluminum blocks do heat up faster vs iron. My 02 aluminum LS1 in my Camaro SS warmed up twice as fast as my Sierra does. Similar size radiators and coolant capacity.

[mr.bill454]

Dont be so down on the alum 5.3 , mine has 98000 hard miles on it, has never burned any oil or ever let me down other than a rusted knock sensor.