head gasket

[don.broadus at exeloncorp.com]

A circle track article awhile back cautioned not to overheat aluminum heads.
The SBC has two exhaust port next to each other
generating lots of heat in that area. It is possible that you have lost the
temper /heat treat of the head and caused the aluminum to be soft in that
area resulting in a poor head gasket crush and resultant water loss. The
heads should be hardness tested before you spend a lot on resurfacing.   
                                       Don

> -----Original Message-----
> From:	Bruce Plecan [SMTP:nacelp at bright.net]
> Sent:	Monday, October 30, 2000 9:08 AM
> To:	gmecm at diy-efi.org
> Subject:	Re: Re:head gasket
> 
> 
> 
> > Ok - due to running way too long with too much advance or something else
> bad,
> > I hope/pray that I now have a blown head gasket.  My engine is slightly
> down
> > on power, gives off clouds of whitish smoke after running for a few
> minutes
> > (which goes away later), and has been using water.  I sure hope it's not
> a
> > cracked block or head!  My question is this . . . what can I do to
> prevent
> > this in the future!  I am using edelbrock aluminum heads, have arp bolts
> > torqued to 75ftlb, using felpro gasket for aluminum heads and run a 160
> > thermostat which maintains 159.4F in the summer.  I do lean on it good
> at
> > least once a day though.
> > Also, what does detonation sound like with aluminum heads, perhaps I
> dont
> > know.  Is it more like a water rushing sound than the rattle tink I am
> used
> > to?  (I get a noise like that at part throttle/hgih map, but get no
> knock
> > counts.  If I turn the timing up , I will get knock counts but no
> audible
> > detonation.  If I turn the timing up even more, I can get audible
> detonation
> > in the rattle-tink form.  I am running 34 degrees total at WOT by 3600,
> and
> > never less than 15 anywhere.  cruise from 20-55kpa at 2000 is 44 deg.
> 47
> deg
> > at 2400.  How are these numbers compared to what others are running with
> al
> > heads.
> 
> Way too high on WOT
> I was running 28-30d  (Using the vette AL heads)
> And too much is cruise
> Matter of fact your beyond the limits of the gm distributors for the SBC
> Also, too cold.
> 
> Yes I know that every engine is different, but small block chevys are
> > preety much a known quality.  Am I in the ballpark here or what?  I know
> you
> > want 36-38 at wot on iron heads, and more initial and less total with
> > aluminum heads.
> 
> Sorry it may have happened, maybe others will learn from this, and read
> the
> archives, and related materials more.
> 
> Damn, I hate when this happens, I try to write enough about tune up, so
> that
> folks do get it, and well, never mind, rant mode off
> Bruce
> 
> > Thanks for listening to my electroyappin!
> > Ryan Hampl
> 
>      I'M ALWAYS FIRST TO THE GROCERY STORE!
> 
> Not with a blown H/G
> 
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