CrossFire/'7747

[Bruce]

FWIW,
just remember, the air's velocity goes up with the smaller bores, and making
the bends to the ports just might try to drop the fuel out of suspension
more so, then larger single bores, would.
Bruce





From: "David & Cheryl Haggard" <david at newcovenant.com>
Subject: RE: CrossFire/'7747
>    So you're the man behind the Crossfire Vault! Cool.
>    Well, I've been keeping most of what I'm doing under wraps, but I'm
> letting people know where they can see how I've gutted and rebuilt my
> Crossfire manifold. The result is a 45% increase in runner size, and still
> keeping most of the manifold anti-reversion capability. See my insanity at
> http://www.newcovenant.com/firebird/slideshows/cfsurgery/
>    Next step is a 1" spacer for the lid, and modify the lid to take the
two
> 2-barrel TBI's. Planning on a pair from 2.8-litre V6 Blazers ('87-'89
> models, I believe). Rated at 300 cfm, a pair should give me the exact flow
> capacity the engine will want.
>    I did all this while keeping in mind that I may have to resort to an
> Edelbrock dual-quad manifold if it doesn't work well or doesn't deliver
what
> I'm after. But then it wouldn't be a Crossfire any more.
>    The very last modification, if it works out, will be some custom bumper
> decals in the original style, but saying something like "2X2 Crossfire
> Injection."
>
> Dave Haggard

> > Of Ken Kelly
> > Subject: RE: CrossFire/'7747
> > It's the stock 350 right now, but will have L98 aluminum
> > heads (I already
> > have them in the garage, going to do some mild porting,
> > mostly cleanup on
> > them) and plan on ceramic coated headers, maybe even gutting
> > the cat and
> > definitely new mufflers (Ravin's, most likely.) Remember too, that the
> > CrossFire is fairly restrictive over 4500 RPM (even well
> > ported,) so I'm
> > really looking to keep a nice torque curve from there and
> > below, where 99.9%
> > of my driving is done.
> >
> > Also keep in mind that this is my daily driver, and I'd like
> > to keep it
> > fairly mild mannered, but with a lot more oomph than it has
> > now. I'm not
> > sure that going to the next step up (214/224 at .050") would
> > gain me much,
> > since most of my driving isn't done in that range, nor is it
> > going to be
> > very effective in a mild CrossFire build.
> >
> > However, I do have plans to throw an Offenhauser CrossRam into my '73
> > Corvette, with either a Holley 4bbl or twin GM 2bbl TBI's on top - the
> > 214/224 would make a lot more sense in that. (Along with a
> > 383, as well.)
> > But, that project is a long way off.
> >
> > Just as you said "it all depends what you're after" .... :)
> >
> > BTW, I'm VERY interested in your project with your CrossFire!
 Ken Kelly

> Of David & Cheryl Haggard
> Subject: RE: CrossFire/'7747
> > The cam I'm looking at is 204/214 at .050" and .420"/.443" lift,
> > with 112LCA.
>    What engine is this-- 305, 350, or 383? Even for a 305, this is a
fairly
> mild cam. For instance, the factory roller cam of my '88's 305 is 207/213
@
> 0.050", with 0.415/0.431 lift and 117 LCA.
>    My new cam choice is going to be a CompCams Xtreme Energy roller, at
> 212/218 @ 0.050, 0.488/0.495 lift, and 112 LCA. Not a big change, but the
> Xtreme Energy ramp profiles are VERY aggressive, and combined with the
drop
> of LCA by 5 degrees I'll get a considerable boost, yet keep smooth idle
and
> high  enough vacuum.
>    For a 350 or 383, Bruce's 224 duration cam would be more like it.
>    It all depends, of course, on what you're after.
>
> Dave Haggard


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