From: J. Lee (milveh@sbcglobal.net)
Date: Mon Sep 23 2002 - 08:23:40 PDT
Light goes on... aha! Hey thanks Gene, Jonathon, Archie, etc.... that
explains it well enough that I get it. I like the serrated surface idea,
seems like gas engines should do that too. Jack
----- Original Message -----
From: "jonathon" <jemery@execpc.com>
To: "J. Lee" <milveh@sbcglobal.net>
Sent: Monday, September 23, 2002 6:47 AM
Subject: Re: [MV] About connecting rods/caps
>
> >Ok, my dumb question of the week......why do mfgs say connecting rod end
> >caps must only fit one way on the connecting rod?
> >
> >The inside of the connecting rod is suppose to form a perfect circle,
right?
> >Now if the connecting rod cap is equal to 1/2 of the round bearing
surface
> >that wraps around the crank journal then obviously its one half a (near)
> >perfect circle. Why in the world would it make any difference to have
the
> >c. rod end cap face one direction or the other as long as the oil holes
are
> >aligned from the top of the c. rod. It forms a complete circle. What am
I
> >missing?
>
> In some cases the connecting rod is not centered on the bearing, Willy's
> jeeps for example. But also that the rods are mated and torqued and then
> machined that way, that's why they are normally stamped on one side not
only
> to get the cap orientation correct but also that you get the right cap on
> the right rod. If you change caps on a rod you have to have a little
> machining operation done where they will actually cut alittle off of the
cap
> and rod and then remate them and then bore it out. Many diesel rods do
not
> even have flat mating surfaces, they are serrated which is better for
> keeping the cap centered but adds other problems such as you only get the
> exact bearing clearance when the bolts are fully torqued.
>
> Does that help??
>
> later,
>
> je
>
>
>
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