Thread: Big Block Chev Block: Iron vs. Aluminum

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I'm in the planning stages of a 540. Considering an aluminum block & heads. A friend who definitely knows his stuff says the aluminum block would not be the way to go in a street driven vehicle, which this engine would be in. To quote him, he said the aluminum block would "move around". I would counter with the fact that the new LS small blocks are all aluminum. Please let me know your thoughts. Thanks.

To quote him, he said the aluminum block would "move around

Tell him you want it to "move around" . . . that's why you're putting wheels on it.

Is your friend an "old wife?" The trouble with depending on "old wives tales" is that they often aren't true.

Do you NEED an aluminum block to get enough horsepower in a big block Chevy for street use? Of course not. You can get more than you can use with an iron block and iron heads. However, an aluminum block and heads will get you lighter weight and a bigger "WOW" factor. If you can afford an aluminum motor and you WANT an aluminum motor, get an aluminum motor. If it's used, though, just make sure it's fully inspected - of course, that's the rule for any motor, not just AL motors.

Final thought. You might want to reconsider that "definitely knows his stuff" line of thought.

Cool thing about aluminum blocks is that you can rebuild them wihtout going to a machine shop. Just throw in some new liners and you're good to go.

I'm a big fan of Aluminum Block V8's.
Just do your research,,and you'll be ok.
Aluminum Block's don't like the same coolants that cast iron do.
You have got to keep an eye out for anything corrosive around your motor.
Power to weight is Supreme.

Don't worry about coolant. Almost all coolant is aluminum compatible nowadays. It used to be that phosphate were added to prevent scale formation on the inside of the block, but it wasn't a big problem and phosphate corrodes aluminum. So, coolant manufacturers just stopped putting phosphate in so they only had to make one mix of coolant.