Fuel injection plugs

[James Ballenger]

Howard Wilkinson wrote:

> James:
>     BMEP is an acronym for Brake Mean Effective Pressure...... It may
> be considered to mean the pressure developed in the cylinder by the
> combusion process.  At low throttle settings BMEP is low, at WOT in
> the max torque range BMEP is max....... Actual BMEP values vary
> between engines as a result of compression ratio, boosting, camming,
> etc.  The max torque developed by an engine per cubic inch
> displacement is a direct relation to max BMEP.  Thus at high RPM BMEP
> values are lower than at low RPM due to lower induction efficiency,
> although the power output BHP is greater.  In general engines live
> longer operating at lower BMEP.....    H.W.

    Thanks for the explanation Howard.  It would make sense since most of
the timing is in by the time todays engines reach peak torque so that at
this point an engine would be doing the most negative torque btdc.  A lot
more bearing wear would probably result.  It seems if we were building
engines for performance at that one point, we could minimize it though.
Also high rpm failures and varying loads due to changing engine speed
would no longer be a factor.

    James Ballenger