The Original 355 took a hit.

[Bruce Plecan]

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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