Dave, the 4.0/4.6 have bigger rod journals, 2.185. New rods are longer and
stronger, 4.0 is 6.11, 4.6 is 5.897, for better torque. To use the older rods
requires grinding the crank to a point where it must be heat treated again. New
pistons are also much nicer pieces that the old stuff with compression height of
1.413 vs 1.95, a much lighter piece without the weakness that caused some of the
earlier pistons to lose crowns at high revs. The neat and much cheaper setup
is a
4.6 with 4.0 pistons and the stock crank, stroke 3.228, with the stock and good
rear seal. John
David Kernberger wrote:
> 10/4/00
>
> Larry,
>
> The stroke on the 300 Buick crank is 3.400". I would love to know
> the stroke on the 4.6 Rover because I am trying to compile specifications
> on all the Rover engines for my own information. The main bearing size is
> also something I want to know. Awhile back listers were saying the 4.6 had
> "larger" mains but nobody stated the actual diameter. The Buick 300 is
> 2.500". I suspect rods have remained 2.000" on all of these engines. Is
> that the case anybody? Meanwhild the Buick 300 crank has a different rear
> flange arrangement; and what about these new style crank driven oil pumps
> and distributorless front covers? There may be several considerations to
> work out here.
>
> Regards,
>
> Dave Kernberger
>
> -------------------------------------------------------
>
> >Just thinking out loud here.
> >
> >I just came across a 4.6 rover engine. I have a Buick 300 crank, heads, rods
> >and pistons.
> >
> >So which one of you out there know about putting the 300 crank in the 4.6
> >engine?
> >
> >I looked through the newsletters but didn't see a reference to this.
> >
> >Isn't the stroke on the 4.6L 3.23" and the 300CI 3.36"? I think the mains
>are
> >the same size and the rod journals are close?
> >
> >OK guys, have at it.
> >
> >Larry Hoy
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