How can one tell if Alum FE Parts/ alum stock are heat treated?

[Qikbbstang]

Looking at the differences heat treating makes (link below) in the hardness/strength ratings of aluminum scares me in that one would expect that not treating to save money and or doing a poor job can weaken the product. Edelbrock states their heads are "A356 aluminum and heat treated to T6 spec". How about all the BBM, Dove, Blue Thuinder etc heads - do they claim/state their heads and other products are heat treated?............................ Further how about alum: Intake Manifolds?....   Water Pumps?    I even wonder about when you buy Alum Stock is that treated?... Can
         Years ago a friend had a hardness tester that I understand was primitive. It consisted of a scale marked glass tube that would be placed at 90-degrees to the surface, a magnetic push release button to drop a captive metal ball and by the height of the bounce back it would indicate the hardness of the surface.  Looking on eBay it looks like they now all measure the bounce digitally and for serious $$$.
         I can see virtually everything from alum wheels to heads could be cheapened by not heat treating. Lord knows the import stuff looks good but may not be treated. Does BBM state their heads are hardened?   How about Blue Thunder?

  I noticed that during WW2 the PT Boats were said to use Alum engine blocks and the alum was anodized to allow use with salt water for cooling. I'd have thought with the aggressiveness of raw water systems and electrolysis some critical sections the alum blocks like head flanges would not last much more then a couple months.

While we're at it I understand welding on treated alum can kill the heat treating as excessively heating the metal. Obviously overheating an alum head can harm the heat treat. Did that blown head gasket happen because the metal between the chambers lost strength after the motor got overheated once?



http://www.mgprecision.com/resources/heat-treatment-of-aluminum-castings-1.html

[jayb]

Any aluminum part that needs to be machined has to be heat treated in some way, because otherwise the aluminum is so soft it tears and folds during the machining operations, and the finished product looks like crap.  I have machined a couple of my prototype intake adapters without heat treating them and they looked terrible.

There are various levels of heat treating, and the best ones are solution heat treated to condition T6.  This means that the aluminum casting is cooked at a very high temperature (around 900 degrees I think) for 24 hours and then quenched in a chemical bath (mostly water) at around 180 degrees.  A casting heat treated to this condition will ring like a bell when you hit it with a hammer; some of the lesser heat treatings will result in a thud when the casting is struck with a hammer.

All my intake adapters are solution heat treated to T6.

[blykins]

Use a hardness tester. 

[dwp]

BBM Aluminum heads are casted with A356 and heat treated to T6 condition.

Doug