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Message
Greetings,
RC Engineering seems to be
a very fast and efficient operation. They just got my injectors today, and
have already called with test results. I sent 4 very slightly used Mazda
550's, and 2 new MSD-2013's, which are supposed to be 50 lb/hr (525
cc/min). They said all 6 injectors were clean, and needed no service at
all. The MSD's flowed less than advertised, but not by nearly as much as I
figured. Here are the results:
MSD- 498,
503
Mazda- 547, 549, 551,
551
I'm sure these are static
flow rates, and I think they also do pulsed flow tests, but I forgot to ask
about that. I'll get them back in a week, so I'll check the results when I
get the data sheets. 50 cc's difference only represents about a 10%
difference in flow, and doesn't really explain the large difference in mixture
that I see on the EC-2. I have to wonder if maybe there's more effect than
the number would indicate, since my MSD's are at the throttle body, with about a
20 inch run to get to the rotors. I can see how this reduced efficiency
might make them seem smaller than they are, but I would also think that Ed would
see the same thing, and maybe he is.
If you guys (Ed and Al)
don't mind, I'd like to propose a test. At your convenience, and I'm
not kidding- don't make any special trips, or go to any real effort. Could
each of you run at low power, below the staging point, maybe 1500 rpm, and
enable only one set of injectors at a time. I'd be interested to see
what position on the mixture knob you have to use for each set. On mine, I
have to turn the mixture knob to about 9:00 for the Mazda 550's, and about 3:00
for the MSD's.
The test will be
interesting, since (as I recall) Al has Mazda 550's as primaries, and also
has the same MSD's that flow about 500 as secondaries. I can't recall if
I've ever seen the physical layout of these though. Are they all the
same distance from the rotors?
Ed, I believe, has matched
injectors, with a large distance between the secondaries and the rotors.
Any difference in his mixture setting will indicate a loss of
efficiency resulting from the large distance.
Sorry to keep dragging
everyone through this, but the difference bugs me.
Rusty (T minus 3 days to
liftoff)
PS- speaking of fast,
efficient operations, I sent my ailing Lightspeed Thirty-3G headset for repair
Monday via next day UPS. Lightspeed got it Tuesday, fixed it, and shipped
it out the same day, via next day UPS. The repaired headset is back in my
hands today, and they threw in a free holder for the battery box that I told
them I wanted to purchase. Bummer that it broke, but mighty friendly
folks, and GREAT service!
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