Fw: Seat material in Corvette heads?

[Bruce Plecan]

This is just a forward, that might shed some light on EGTs, for the new
guys.
Maybe even some of the old timers.
Grumpy

----- Original Message -----
From: Leone, Thomas (T.G.) <tleone at ford.com>
To: 'Bruce Plecan' <nacelp at bright.net>
Sent: Friday, December 10, 1999 7:26 AM
Subject: FW: Seat material in Corvette heads?|
| Sure, go ahead and forward it, with my name.|
| Regards,
| Tom Leone <tleone at ford.com>
| -----Original Message-----
| From: Bruce Plecan [mailto:nacelp at bright.net]
| Sent: Thursday, December 09, 1999 5:58 PM
| To: Tom Leone
| Subject: Re: Seat material in Corvette heads?
| My I forward this to another list?.
| I'll delete your name if ya want, just that it's a good light read and
| interesting.
| Bruce

| | I wouldn't worry about exhaust temperature under those conditions,
| | it is actually lower under lean conditions than at stoich.  This
| | is commonly misunderstood, because at wide-open throttle people
| | worry about exhaust temperature when "lean".  They should worry
| | about exhaust temperature when "not rich enough" because exhaust
| | temperature peaks at stoich and goes down on both the lean and
| | rich sides (temperature at 13:1 A/F is roughly the same as 16:1).
| |
| | I should note that this assumes you re-adjust spark to MBT for
| | each A/F.  If you don't adjust spark, going lean causes slower
| | burn rate and therefore higher exhaust temperature due to
| | combustion later in the expansion stroke.
| |
| | Also, exhaust temperature is a pretty strong function of RPM
| | and torque, so lean at part throttle low RPM should be fine
| | compared to rich at high RPM wide-open throttle.  My only
| | concern would be whether the oxidizing environment of lean
| | burn causes a problem.  I have seen engines with hundreds
| | of hours of dyno time under lean conditions, with no problems,
| | for whatever that's worth.
| |
| | Tom Leone <tleone at ford.com>