Stan

Thanks for the commentary. I had forgotten about the aluminum pistons
thing, and connecting rods. Even my old airplane, a Cessna 195 with a
300 HP radial engine had aluminum rods. At least the secondary rods were
aluminum. The master rod was steel. Interesting thing about the old
radial engines. The was only one crank throw on the crank shaft. There
was only one rod connected to the one crank throw, and it was called the
master rod. All the aluminum rods were connected to the master rod. One
heck of an arrangement but it worked.

BTW, the Aluminim rods did not have replaceable bearings. The rod was
the bearing, and when the bearing surface  wore out, you just replaced
the connecting rod with a new one.

Regards,

John Rodgers
88 GL Driver

Stan Wilder wrote:

>Castings can be forged or shot peened for more strength.
>However castings are considered less in strength in most applicatioons.
>Milled from solid stock is considered the strongest but by far the most
>expensive because of process time and waste.
>Example: Pistons are Cast but also forged for more strength. Aluminum
>Connecting rods are forged from blanks that are cut from sheet stock
>.......... but they still break.
>
>Stan Wilder
>
>----- Original Message -----
>From: "John Rodgers" <jh_rodgers@BELLSOUTH.NET>
>To: <vanagon@GERRY.VANAGON.COM>
>Sent: Tuesday, June 29, 2004 2:43 PM
>Subject: Curious Question (NVC)
>
>
>
>
>>I'm not an engineer, but have a question.
>>
>>Cast aluminum has a granular crystal quality in it's structure. Milled
>>Aluminum (hammered, rolled) does not.
>>
>>Of two identical parts, one a machnined aluminum casting, and the other
>>machined in milled aluminum, which would most likely have the best 1)
>>strength 2) heat transfer properties.
>>
>>Inquiring minds would like to know!
>>
>>Anybody??
>>
>>Thanks,
>>
>>John Rodgers
>>88 GL Driver
>>
>>
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