X-Mozilla-Keys:                                                                                 

Tony wrote:

Paul,
    I wrote several weeks ago seeking comments on the possibility of
lowering rotary EGT by running much higher fuel pressure to the injectors

=>

than 70psi.  An engine guy conducting a forum at Arlington intimated that
there in fact had been testing accomplished verifying this phenomenon.
    What do our readers think???  Tony Livic

Well perhaps there is better vaporization and you get less unburned
Hc in the exhaust to burn in the exhaust manifold. Who was it that
said that?


Paul Lamar

Tony wrote:

Paul,
    Eric Ahlstrom
CEO Star* Aviation
(formerly Applied Force Engineering) conducted the forum at Arlington and
made the statement that higher fuel pressures at the injectors will yield
higher HPs, lower BSFCs and much lower EGT on rotary engines and this data
was gathered empirically by DARUS47959@aol.com .   I contacted Darus and he
replied with the following: "Alstrom was correct.  We are seeing power gains
and EGT reductions and or
lower fuel burn as compared to previous specific power settings when we run
a
smaller than before injector, but at pressures in the 72 psi range.  What is
changed is the fuel atomization.  In a development program for Silver Arrow,
an Israeli military drone manufacturer, for a rotary based on the Norton
rotary we saw an 8% change from the 43 psi fuel rail injectors versus 72
psi.
This changed again by 10% when went to 100 psi, and totaled 29% at fuel rail
pressures of 210 psi.  Above 72 psi the injector life starts dropping such
that at 72 psi we changeout the injectors at 650 hrs.  Darus Zehrbach"
    If it is possible to reduce EGTs in the 13B by 8% (140 degrees)
configuring the engine with a garden variety auto turbo would seem
plausible.  Size the turbo for conservative boost w/o wastegate, take
whatever HP gain that yields and have an adequately muffled exhaust system
as well.  Sounds like a win win - two years ago at Sun & Fun Tracy Crook
lamented the fact that the high EGT inherent with the 13B made turbocharging
possibly more complex than it was worth.  Maybe there is still a small bit
of light at the end of this tunnel???

Tony Livic

I think that is before Tracy knew about Inconel turbines.
140 F is good. Well worth doing. Gives more margin with
Inconel.

Paul Lamar

 
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