"Pink" versus PM rods

[Gary Derian]

John Lingenfelter, in his new book, noted that he has seen failures in the
new PM rod which he had not seen in the old "pink" rods which by the eay are
forged steel not cast iron.  I know GM claims the new rod is better and
there are advantages of PM construction and modern CAD designs.  I was just
relaying Lingenfelter's comment.

Gary Derian <gderian at cybergate.net>
-----Original Message-----
From: Daniel Burk <ws6transam at voyager.net>
To: diy_efi at esl.eng.ohio-state.edu <diy_efi at esl.eng.ohio-state.edu>
Cc: gderian at cybergate.net <gderian at cybergate.net>
Date: Thursday, February 07, 2036 5:08 PM
Subject: Re: "Pink" versus PM rods


>Gary,
>
>The Pink rod is NOT stronger than the powdered metal rod; at least
>according to GM.
>
>The PM part has better weight distribution, no casting flash, smoother
>finish, and is also harder than cast iron.  Newly designed rods can also
>be pressed as a one-piece unit, including the rod end. The end cap is
>then "snapped" off such that when re-attached, the crystalline pattern
>acts as a retainer, thus easing side-loading of the bolt. The bolt need
>only to confine forces in which the vector passes up the longitudinal
>axis of the rod.  The rod itself constrains the other forces!  Of
>course, you can't mix & match rod caps with other rods.  I am unsure if
>the LT1 rod takes advantage of this, but the '99 Ford modular V8 is
>slated to use this technology.
>
>One other advantage of PM rods might be in their weight variance. They
>may be more homogeneous and require less balancing.
>
>A point of trivia: A PM part is porous. As such, it can be impregnated
>with oil, which may aid in lubrication of the wrist pin and/or crank
>interface.
>
>    --- Daniel Burk
>