Quote:
Originally Posted by moore_rb
I'm with this guy...- Most dudes are going to tell you they want aluminum instead of iron for both the reasons you mentioned - Weight, and for the "cool factor"
But my personal opinion is that these 2 reasons mask the real rationale, which is technical ignorance, augmented by a fat checkbook...
"A fool, and his money, are soon parted"
- Benjamin Franklin.
It's the same reason that guys are coming to you asking for a 700hp solid roller, for a car that they put 500 miles a year on, driving around to car shows and parking lot meets. 
Bench racing is fun, without being nearly as scary, or time consuming, as the real thing...  |
Not sure why you would say it is technical ignorance. The aluminum block weighs about 60 lbs less than the iron block. That's not insignificant if you care about weight. And if you choose an iron block and aluminum heads you have to consider the thermal expansion differences and what issues that may or may not create. Going with the iron heads adds more weight.
I made a very conscientious decision to choose aluminum for the engine block in my car due to the resale value and because it is in keeping with the "technology" and low weight focus of the Kirkham product design (billet suspension components etc). I don't think that makes me a "fool" or a "bench racer".
There is no question that aluminum sand castings have more porosity issues than cast iron components - this is a problem in the aerospace parts world also and the associated casting yield gets built into the cost of the parts. There are ways to help mitigate it such as hipping, mold and core design, mold heat and pouring technique but none are foolproof nor inexpensive and certainly not approaches that are well suited to low volume production.
It will be interesting to see 3D printed parts when the additive manufacturing machines get large enough to make them.