Well, I can think of two examples. 1) how do you think that piston gets
down the bore on the intake stroke? It is pulled by the rod ceing
connected to the crank; 2) guess what stops the piston at the top of the
exhaust stroke? Yup, that rod between the crank and the piston. The
friction forces on the piston add to the inertia loads of that
reciprocating hunk of metal.
Others have said it pretty good regarding the fatigue life of aluminum
parts. Fatigue just seems to build in al until it snaps. Add heat and it
probably gets worse, so when you start pushing and pulling on the rod,
well, it will break, sometimes sooner than expected.
Hope this helps,
mayf, bored in pahrump
Benn wrote:
>Hmm, 14.7 psi acting on a 4" dia. piston is less than 200 pounds. I
>would've thought the compression/buckling loading of the rod due to high
>rpm dynamic/mechanical loading (whether WOT or not) would be the most
>likely failure mode....but then again, the only rod I've had
>rough-machine my block was due to spinning a bearing, thereby putting
>the rod into bending as the big end tried to seize on the crank. How
>have rods failed in the examples you've seen? (Others welcome to
>comment on their experiences in causes of rod failure).
>Benn
>
>----- Original Message -----
>From: "Richard Fox" <v4gr@rcn.com>
>To: "land-speed" <>
>Sent: Tuesday, January 17, 2006 4:24 PM
>Subject: Re: Rods - Aluminum or Steel
>
>
>
>
>>Really I guess that wouldn't apply if you had your foot in it, dirt
>>
>>
>tracking
>
>
>>though at full lock. Really what I should have said is backing off for
>>
>>
>the
>
>
>>corner. RF
>>----- Original Message -----
>>From: "Benn" <karhu@california.com>
>>To: "Richard Fox" <v4gr@rcn.com>; "John Burk"
>>
>>
><joyseydevil@comcast.net>;
>
>
>>"land-speed" <land-speed@autox.team.net>
>>Sent: Tuesday, January 17, 2006 03:39 PM
>>Subject: Re: Rods - Aluminum or Steel
>>
>>
>>
>>
>>>that Aluminum rods fail due to tension loads, usually.
>>>
>>>
>>>>Like backing into a corner at Eldora.
>>>>
>>>>
>>>Huh? What's the reference and why does that lead to extraordinary
>>>tension loads?
>>>Benn
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