Can anyone give an informed opinion about injector diffusers?
<Big Snip>
John Gibbons wrote:
Brian, Paul and all,
My experience with the diffusers was after I put my 13B
back into my 86
RX7. After the first few weeks the car would not idle. I traced
it to the
injector seals and the problem went away when I replaced the
seals. Not for
long though. I finally realised I had missed putting the
diffusers in the
new housings so the seals were able to float and would twist a
little under
very low MP. Once they had twisted the manifold would leak
again. When the
seals were effective though the car performed in the same
manner as it does
now with the diffusers and seals in as they should be. There
must be some
difference or Mazda wouldn't bother with them, but from a driving
stand
point I couldn't notice one.
I read the post on the insurance issue with great interest,
although it
is not effecting me directly yet, it is the hot topic on the
Christavia
group as one builder in Ca. is not able to get insurance for
his Ford V-6
aircraft. As he hasn't got insurance on it, he is not allowed
to move the
project into his hangar at the airport from his basement
workshop for final
assembly. There have been a few e-mails fired off to EAA and AOPA
with
polite but so far unproductive responses. As a guess I would
figure 40 % of
the group would fall into the conversion category. Most of the
Glastars I
have flown or am familiar with are conversions also. I have a
NSI Glastar to
flight test when the weather improves a little. It will be
interesting to
see how it performs. I know it won't compare to a rotary one
Paul but I bet
it will be better than the Lyco I did last.
John
"Del Johnson, North Point Solutions, Inc" wrote:
If you look a a diffuser, there are two O-rings on the diffuser and none
on
the injectors (only a large thick compressable 'washer'). This would
confirm the John's findings that the diffuser is also needed to seal the
chamber.
On a relate note, I probably should replace the injectors that came with
the
engine. The plastic coating at the injector tip is cracked and flaking
off
on two of them and the thick seating 'washer' is split on one injector.
I'm
also looking to make or purchase some injector bosses for welding onto
the
intake runners. Is it recommended to stay with the original Mazda
injector
or should other injectors be considered, from a cost, performance or
reliability standpoint? The companys that sell injector bosses also
sell
injectors that fit their bosses. I would have to research further with
them
to determine if their injector bosses work with the mazda injectors but
if
it doesn't matter it might be easier to purchase the entire kit from the
company and go with a different brand of injectors.
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
The stock Mazda injectors (normally aspirated) are around 50lb/hr. One
builder got away with using 36lb/hr parts but I wouldn't recommend anything
less. The EC2 can be used with either type (low or high impedance) but a 5
ohm resistor in series must be used with the low impedance type. (This is
what Mazda does too)
I used the diffusers on the primary injectors but not on the secondaries.
Didn't seem to make any difference at high throttle where the secondaries
kick in.
Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com
Hopefully the internet will not macerated this table quite so bad.
Damn Steve Jobs and his pansy GUI fonts. We did not have these
troubles back in the old DOS days of strictly ASCII characters :)
Paul Lamar
The AirCraft Rotary Engine NewsLetter. Powered by Linux.
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Copyright 1998-2002 All world wide rights reserved.
Fuel Injector Flow Rates compiled by steve@aems.com.au
Injectors listed by flow rate, from lowest to highest
Manufacturer___Part Number__cc per____Colour_____Ohms___lbs per___Est___Press__Vehicle Engine
_____________________________minute_______________________hour_____HP____Kpa
**********************************************************************************************
Nippon Denso__________________250__yellow/orange__1.7_____24.5____50.0____255___Toyota____22RTE
Nippon Denso__________________250_________green__13.8_____24.5____50.0____290--Toyota_____4AGE
Nippon Denso__________________250________violet 13.8_____24.5____50.0____290 Toyota_____4AGE
Nippon Denso__________________250_________brown 13.8_____24.5____50.0____255 Toyota_____3SGE
Nippon Denso__________________251________violet 13.8_____24.5____50.2____290 Toyota____1UZFE
Nippon Denso__________________282___light green 13.8_____27.6____56.4____290 Toyota_____2RZE
Nippon Denso__________________282________violet 13.8_____27.6____56.4____290 Toyota____2TZFE
Bosch________0 280 150 802____284_________________________27.8____56.8____300 Volvo B200Turbo
Nippon Denso__________________295________yellow___2.7_____28.9____59.0____255 Toyota_____7MGE
Nippon Denso__________________295________pink_____1.6_____28.9____59.0____255 Toyota____22RTE
Nippon Denso__________________295________green___13.8_____28.9____59.0____255 Toyota_____3SGE
Bosch________0 280 150 811____298_________________________29.2____59.6____350 Porsche__944 Turbo
Bosch________0 280 150 200____300_________________________29.4____60.0____300 BMW________
Bosch________0 280 150 335____300_________________________29.4____60.0____300 Volvo B230 Turbo
Bosch________0 280 150 945____300_____red/brown___________29.4____60.0_________Ford MotorSport
Nippon Denso__________________315_______pink_____13.8_____30.9____63.0____290 Toyota_____3SGE
Nippon Denso__________________315___light green__13.8_____30.9____63.0____290 Toyota_____7MGE
Bosch________0 280 150 402____338_________________________33.1____67.6____300 Ford________
Bosch________0 280 155 009____346_________________________33.9____69.2____300 Saab____Turbo
Bosch________0 280 150 951____346_________________________33.9____69.2____300 Porsche______
Nippon Denso__________________365____red/orange___2.9_____33.9____73.0____255 oyota____4AGZE
Bosch________0 280 150 024____380_________________________37.3____76.0____300 Volvo_____B30E
Bosch________0 280 150 036____380_________________________37.3____76.0____300 MB________4.5L
Bosch________0 280 150 043____380_________________________37.3____76.0____300 BMW__________
Bosch________0 280 150 835____397_________________________38.9____79.4____300 Chrysler____
Nippon Denso__________________430_________black___2.9_____42.2____86.0____255 Toyota__7MGTE,3SGTE
Bosch_________R 280 410 144___434_________________________42.5____86.8____300 Bosch R___Sport
Bosch_________0 280 150 400___437_________________________42.8____87.4____300 Ford_____4.5L
Bosch_________0 280 150 401___437_________________________42.8____87.4____300 Ford_________
Bosch_________0 280 150 041___480_________________________47.1____96.0____300 MB_______6.9L
Bosch_________0 280 150 403___503_________blue____0.5_____49.3___100.6____300 Ford_________
Conversion From cc per min to lbs per hour to HP.
500cc per minute is approximately equal to 49lbs per hour which is equal to approximately 100 HP.
Common conversions
lbs/hour = cc per minute / 10.2
lbs per hour = HP / 2.04
cc per minute = lbs per hour x 10.2
cc per minute = HP x 5
HP = cc per minute / 5
HP = lbs per hour x 2.04
Note: This is a rough guide for conversions and flow rates.
If you have any information that would help in increasing the quality of this data base,
please send email to steve@aems.com.au.