vortec heads

[Tim Welden]

I'm running the L31 vortecs on my 383 TPI engine,  For me, I ended up going
with KB -18cc dish piston, -.010 deck height, & .028 head gaskets.  This put
my quench height near .040 and the C/R at about 9.6:1 static.  I've only
been driving it a couple of weeks but so far no noticable detonation.  This
is in Denver so the 5K' in altitude I'm sure helps too.  I'm stll using a
stock '88 MAF chip & sensors.  Once the holidays wind down I hope to beging
tuning to see if I can optimize the setup but I'm really happy with the way
it runs so far -- no comparison to the stock L98.  Wish I had a dyno to see
what it was actualy putting out.

YMMV,
-Tim-

-----Original Message-----
From: Eric Bryant [mailto:BRYANTE at ghsp.com]
Sent: Monday, December 18, 2000 8:06 AM
To: 'gmecm at diy-efi.org'
Subject: RE: vortec heads


> From: Bruce Plecan [mailto:nacelp at bright.net]
> Subject: Re: vortec heads
> 
> Your correct on all counts.
> far better to use a dished piston, to even further min the 
> squish area, CR
> permitting.   You want to get the greatest volume of gas as 
> close to the
> plug as possible.

I'm not sure what the Vortec pickup motors use, but the LT1 and LT4 use
flat-top pistons to create the correct squish area.  The tech notes that
come with the Fast Burn heads state that they should also be used with
flat-tops for the same reason.  I think they're doing that to accomplish the
same goals that you speak of (creating a uniform combustion chamber shape
that's centered around the plug).  I don't think that dished pistons would
screw that up, but you'd lose compression ratio (and one of the nice things
about the "modern" combustion chamber shapes is the ability to run a higher
CR).

Eric Bryant
mailto:bryante at ghsp.com
http://www.novagate.com/~bryante 
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org
----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org