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 AirCraft Rotary Engine NewsLetter. Powered by Linux.
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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.