The Original 355 took a hit.

[rr]

Bruce,

Just wondering, what/whose head gaskets were used on this engine?

BobR.


Bruce Plecan wrote:

> From: "Dave Zug" <dzug at delanet.com>
> > We can rebuilt it... we have the technology..
> > Better, Stronger, Faster.
>
> At this stage, it's just seeing how far it will go.
> Also, bare in mind the lil guys used the FBod for parts chasing.
>
> > The standard abrasives doc (on street level head portintg) is a nice
> > document, if you have not seen it... I can't imagine you have not, but on
> > the topic of DIY, its directed to others.
> > http://www.sa-motorsports.com/diyport.htm
>
> It's almost funny that people make money off of pocket porting.
> GM has the shape about right, and if you just clean up the production part
> of things usually have a decent head.  generally the short side radius is
> poor just from coring, and little errors in initially locating the
> machining.  Taking the sholder of off the valve guide is another quick gain.
> The trick is really knowing when to stop.
> you can do too many  good things and wind up with a lousier then stock head.
>
> Gotta repeat after just knocking the edges of off the chambers is a real
> winner.
>
> > I'm lookin for "donor" (don't read: donated) parts for the budget 400 TPI
> > project, if anything fell off that aint goin back on .. like those heads
> ;-)
>
> These are the first gen D port AL vette ones.
> For the money would be hard to beat, thou some of the new iron ones sound
> like fun.
>
> Was loooking thru some other heads at a friends shop.  The Edelbrock RPMs
> seemed to have things well in hand for someone not wanting to get gritty
> with grinding.
>
> > PS (Thanks, I'll stop thrashing my car in 20 degrees now - you may have
> just
> > saved me $4k)
>
> Just back the timing up a few degrees.
> I peeked at some gm S/C MAT tables and they danced the timing around 10
> degrees from cold to hot vs Airflow.
>
> I think, I'm going to use something like
>
> 50-70dF as being the 0 correction area,
> Then 70-90 add 2
> 100+ a total of 3
> 30-50dF  2 less
> single digit to 30s 4 less
> there I said it <g>
> Bruce
>
>     So far, both the GN and SBC seem to like this, though, haven't had any
> traction for testing in the lower temps., thou the plugs bare this out.
>     Also, entertaining using the cross fire with two small two barrel TBIs.
> It already took the 90#/hr injectors to feed her, so the with this can run
> (4) 55 #/Hr injectors, though would mean an injector driver board.
>     thou I have a dual butterfly 2"er sitting on the kitchen table
>
> >
> >
> > ----- Original Message -----
> > From: Bruce Plecan <nacelp at bright.net>
> > To: <gmecm at diy-efi.org>
> > Sent: Saturday, January 27, 2001 3:40 PM
> > Subject: The Original 355 took a hit.
> >
> >
> > >
> > >
> > >
> > > The 355 that I wrote about in tuning tips, and used for lots of 747
> info.,
> > > finally had it's first internal problem.   Well over 100 1/4m passes,
> and
> > > too many 600' passes to even guess at.   Now at about 70K miles, it's
> > blown
> > > a headgasket.  Happened on a really cold night, and the stations are
> known
> > > for adding lots of alky during the cold season, so I'd be easily talked
> > into
> > > it being not a real tuning problem, per se.   It microscopicly (?) blew
> > the
> > > fire band over maybe .020" near a water passage hole (rear side of #7).
> > My
> > > best guess is that there was a tank or two of heavily alkied fuel, and
> was
> > > just enough trace detonation that it silently lifted the head.   We've
> had
> > > enough single digit temps., that I just should have taken an addition 2
> > > degrees of timing due to the weather <sigh>.....
> > >   Just to summarize, this was a Comp Cammed, 9.5:1 AL vett headed SBC.
> > >   At this stage the hone pattern is fully intact,  the pistons still
> have
> > > there crisp corners at the perimeters, no incidation of any valve
> burning,
> > > no large amounts of Carbon,  in general the wear is typical of a 10K old
> > > stock engine.
> > >
> > > While apart, for the gasket change, going to clean the chambers (smooth
> > > them, to avoid any machining edges), do a little pocket porting, and
> > freshen
> > > the valve job..
> > > As much as a success this engine has been, just can't help to entertain
> > the
> > > idea of surfacing the heads, and tweaking it up a little more in HP.
> > > While not a screamer HP wise, it's spent alot more time at WOT then most
> > any
> > > other street motor that I can imagine.
> > >
> > > Course, there are some ecm options, for things to do <g>.
> > >
> > > Course being the President of CSH, I'm also a customer.
> > > Bruce
> > >

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