CrossFire/'7747
Ken Kelly
ken73 at ken73.homeip.net
Wed Jul 18 19:49:05 GMT 2001
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!
"The Third" Ken Kelly
-----Original Message-----
From: owner-gmecm at diy-efi.org [mailto:owner-gmecm at diy-efi.org]On Behalf
Of David & Cheryl Haggard
Sent: Wednesday, July 18, 2001 1:49 PM
To: gmecm at diy-efi.org
Subject: RE: CrossFire/'7747
Ken,
> 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
1988 Formula Firebird
305 2 X 2-bbl CFI (under construction)
http://www.newcovenant.com/firebird/
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