effect of crank endplay on pistons/rods?

[auditude at cox.net]

Jim Green <jeg1976 at yahoo.com> wrote:
>
> --- auditude at cox.net wrote:
<snip>
> > This
> > would be an interim stage towards further mods, and
> > I would want to get about 300hp or so using these
> > and other used parts.
> >
> > This combination would reported get me the AAN-ish
> > c/r of like 9.35:1 or so, which I would try to be
> > running with the motley crew of a MAC11B ignition,
> > Megasquirt EFI, and Saab APC boost control.
> >
> > Does that high of a compression ratio on a turbo
> > motor "require" the sophistication of the native
> > 20vt Motronic engine management?  I've been
> > targeting a c/r of around 8.5:1 for the final
> > configuration, hopefully able to reach 400hp still
> > using the above wierd stuff.
>
> Man, that's pretty high, just the higher compression
> of the MC2 makes it much more succeptable to knock
> that my old MC.  I'd say that's just a little to high
> for that ECU to control without some major
> programming.  You could add some water injection with
> the dual table code of the megasquirt and you may be
> able to pull it off.

Hi Jim,

Yeah, it is a high c/r.  I'm just wondering about this because I came across the parts.  Is the challenge more fuel-side, ignition-side, boost, or everything?  I was thinking if the APC worked, I could run next to no boost if it would keep it from knocking, just to get things rolling for a while.

> Also, from what I've heard,
> you'll be pushung your luck, and maybe your car if you
> run 400 hp with those rods.

No, I wouldn't be using those stock rods in that stage.  That stage would be different pistons and rods.  I was thinking I could get these used pistons and rods for cheap, and get the rest of the car configured about the 20vt, like manifolds, fuel rails, and so forth.  Above I'm trying to say that I would target 300hp for the used AAN parts with the mix-and-match management setup.  The 400hp reference was to the later 8.5:1 c/r configuration, and the "other parts" would be rods and pistons and maybe other stuff.