----- Original Message -----
From: Frank van Dalen <frank.vandalen@fae.storkgroup.com>
To: mgb-v8 <mgb-v8@autox.team.net>
Sent: Tuesday, June 13, 2000 4:38 AM
Subject: Fw: Inlet manifold - paint or powder coat?
Hi Frank,
Why pre-heat the intake air?
Ideally is to have cold thoroughly atomized fuel mixed in cold air to enter
a hot combustion chamber to heat (vapoize) fuel in combustion chamber. Cool
intake manifold walls tend to condence fuel on it's walls. This removes fuel
from the mixture and causes droplets of fuel to enter combustion chamber. As
for sharp edges inside intake track. That could cause some turbulence which
would help mixing of fuel/air but turbulence also restrects flow. More
likely reason was cost to manufacture to clean it up. Most of this effects
only high RPM operation but could have effects on mid-range acceleration.
The heating of manifolds is done for drivability problems and emmissions.
The warmer the air/fuel mix is in the manifold, the less you can get into
the combustion chamber but the better mixing and some pre-vaporized fuel.
A compremise seems to be a clean intake design (not polished) with a
controlable intake heater for cold engine operation.
Howard Fitzcharles
http://hmfinc.home.mindspring.com
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