<Big Snip>


That brings me to the next question, what are the injector specifications
that I should use if I don't purchase replacement mazda injectors?  I

know

they should be of the high resistance > 13 ohm to work with Tracy's

system

but I'm not sure about nozzle flow rates.  Also, are the primary and
secondary injectors different?  Related to the injector diffuser

question,

if you replace the injectors with a different make should they work

with and

fit into the mazda diffuser?

Del Johnson - Another Glastar builder

Tracy says the engine needs up to 18 gallons an hour at full power.

BTW least you think that is high you would be wrong. 200 HP aircraft
engines also need that kind of fuel flow at full power.

I would say 20 gallons per hour to be on the safe side. Since there
are four injectors that is 5 gallons per hour or 30 pounds per hour
per injector. I'll be using the stock Mazda 88-91 turbo injectors. At
least initially.

Paul Lamar

List,
Summit Racing carries Ford 30lb injectors (set of 8, of course) for

$210.  Maybe it would be worth just buying new injectors instead of
fooling around with the old ones.

Ken Powell

What was the pressure required for 30# flow?

For those of us assembling engines from parts this is the way to go.  We
should pair up on these sets of 8 as $105 /4 injectors is a good price last
time I checked.  Anyone in the Portland, Oregon area needing 4 injectors
besides me?

Also, just checking calculations here, you want to size your injectors for
your engine at 80% of rated capacity.  That is if you need 30 pph (per
injector) your injector should be rated at 37.5 pph.  If we use 0.6 pounds
of fuel per hp per hour (Max rich mixture):

200 HP * (0.6 #/HPhr) = 120 #/hr    equals 30# injectors

Correction for 80% duty cycle:  30#/80% = 37.5# injectors

For 30# injectors this back calculates to 160 HP.

Also 2, if you are planning to be able to fall back to 2 injectors per the
capabilities of Tracy's EC2 you need to decide if (in the above example)
100HP is enough to get you home.  If you need more than that, run the calcs
for two injectors at minimum HP and 80% duty cycle.  A typical RV can
easily make it home on 100 HP if you don't have to climb faster than a
C-150 on a hot day.  OTOH I'd be looking for the nearest airport.  A
Glastar might be fine on 100 HP, but, you need to ask the Glastar experts
for that.  Tailwinds, I don't have a clue, Jerry?

Mike

Mike McGee, RV-4 N996RV, O320-E2G, Hillsboro, OR
13B in gestation mode

 
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