Guys,
It seems this topic has already been extensively debated on the HiPo Mustang
List. One noteworthy thing I found out was that Bob Mannel has interviewed
an ex-Ford employee that claims to have been acquainted with the manufacture
and testing of the HiPo cranks. Here is Mannel's statement of what he
learned from him:
"A former Ford employee who worked in the engine foundry during the time 289
HiPo's were produced was able to shed some light on this ground area. He
indicated that the molten metal used for higher nodularity castings, such as
the 289 HiPo crankshaft, had increased amounts of nickel and manganese
added. After the casting process was completed, the 289 HiPo crankshaft rear
counterweight was ground smooth so that the higher nodularity content could
be verified by visual inspection under a microscope. (The grains, or
nodules, within a specific circle were counted and the number had to meet a
particular criteria for the metal to be considered of "high nodularity.") No
other hardness testing was done on 289 HiPo crankshafts with the ground
smooth counterweight."
There is also a contingent that disagrees with this and maintains that the
HiPo cranks were nothing special, just randomly selected standard cranks
that past the hardness (or possibly visual) inspection. I have heard the
"high nickel content" story before, which included the HiPo blocks as also
having higher nickel content. I'm more included to believe that's true of
the cranks than the blocks, which I doubt started out any different than a
standard block.
If you want to check the archive of the discussion on the HiPo Mustang List,
here's the link:
http://www.hipomustang.com/hpmx/topic.asp?TOPIC_ID=1184&ARCHIVE=
Regarding, the "bell ringing" test for a HiPo crank, there are many
references online to using this as a test of a cracked crank. That's not to
say that a HiPo crank wouldn't ring louder and longer than a standard crank;
if it was harder it certainly should. In fact, I think I've had the
difference demonstrated, but with the passage of time, I can't attest to how
dramatic the difference was.
Bob
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