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Message
----- Original Message -----
Sent: Saturday, March 27, 2004 12:27
PM
Subject: [FlyRotary] One step forward and
.9 steps back.
While trying to solve the low RPM running of my engine I thought maybe my
EGR ports were not plugged well so I spent a day taking off the turbo and
manifold, more thoroughly blocking the EGR - no effect. I was also able
to set the injector transition below idle. It runs the same on either
the primay or secondary injectors. The timming is checked with a light,
and both sets of plugs seem to be working properly.
Here are my current
issues submitted for your perusal:
Problem 1: It runs great over
about 1900-2000 RPM, but slowing down through that speed (a MAP of about 14)
it begins to run rough and requires an extra rich mixture to run at all.
The MAP also goes up to about 17 or 18 despite a fall in RPM. It is as
if when the RPM gets low it cant suck enough vacuum then the computer starts
using the wrong part of the MAP table. I am about ready to set the idle
at 2000 and say problem solved. Sound reasonable or is something
wrong?
Set it for 1900-2000 idle and press
on. With my latest manifold it will idle (poorly) down to around 1100
rpm (appears to be too rich), but there is really no reason not to idle at
2000 rpm, the fuel saved between 2000 rpm and say 1600 rpm for the amount of
time you will spend at idle is almost undetectable. With just a prop as
a flywheel mass, the engine just seems happier with a bit more rpm for
idle. Perry can idle at a lower rpm with his direct drive because as
best I recall he uses the more massive Manual transmission flywheel (20
lbs?)
Problem 2: I was very disappointed to discover that turning off
the alternator makes the engine barely run, especially with any other
electrical load, even with 2 batteries connected. They are fresh
healthy batteries. The voltage drops from 14.2 to 11.5. If running
at less than 2300 RPM when the alternator is turned off the engine begins to
surge or stops running all together (however, running on just one set of coils
improves the problem.) If running at higher RPM the engine will just sag
a little.
I agree this is your most serious
issue in my opinion. With two batteries (17AH), my engine did not even
notice that the alternator is not on line. However, my voltage does drop
from the alternator 14.4 to the battery 12.3 volts. I have no idea how
much current the LS1 coils draw, but the Mazda coils appears to be in the
vicinity of 5 amps average. The fuel pump would add another 5-7 amps
depending. Injectors would probably average 2-4 amps (depending on
whether the low impedance or high). So if my figures are anywhere close
a fully charged 17 AH battery should last at least 30-45
minutes without alternator. Two should, of course last longer.
I would have no less size than #4
cable running from my battery to the bus. Any smaller and your
nominal current draw could cause a voltage drop. Also check your
wiring and make certain both batteries are actually on-line and servicing your
high amp components.
I wonder if the LS1 coils have a
higher minimum voltage than the stock. Perhaps they take a higher
current surge to saturate the magnetic core?
This calls in serious issues about my electrical reliability. I
may decide to install a switch to disable one set of coils, or trading the
momentary switch that came with the EC2 to a regular 3 position switch.
Those LS1 Coils sure do seem to need a lot of Juice.
Problem 3: (THE
BIG PROBLEM) My coolant doesn't seem to be flowing well, despite the fact that
I have no thermostat and have welded the bypass passage in the pump
housing. I ran for almost an hour at 3000 RPM with no apparent
problem. Going up to 4000 RPM after that the coolant quickly overheated
and boiled over. Surprisingly, the radiator was just luke-warm.
Now I am really worried. I remember that someone else recently was
having a similar problem but I lost track of how it was solved. I am
considering some possible causes. A) My AN-16 hose (engine to Rad) maybe
is just not big enough - unlikely because the fitting on the rad doesn't even
get warm. B) the Water pump sold to me by Adkins is really for a
3rd gen and is running backward. - possible because the outlet side of the rad
seems to get warmer than the inlet side, but only slightly maybe and it is
closer to the turbo. C) I have a flap of rubber partially blocking
the outlet hose. D) The pump just refuses to properly prime
itself. E) Maybe the thermostat bypass passage is not properly welded
closed. - can't see it because of the welded plate, will have to look with a
dental mirror. F) ???? any input or other ideas?
Regarding cooling: A.
The AN-16 should be plenty and not a part of the problem B: Don't
know on this one but I would presume the pump would be a bit less efficient if
running backwards - perhaps not enough to cause these types of problems, but
on theother hand it wouldn't be helping. C: Could be I suppose, but I doubt
it. Hard to say about the rest.
Dave, a possibility that might account for the
symptoms you are seeing is air trapped in the cooling system. If your
coolant is getting hot enough to boil but your radiators are only luke warm,
then entrapped air could account for many of the symptoms you are
seeing. In my system, you can feel the sides of the radiator tanks and
determine how much coolant is in the radiator. Its hot where the coolant
is and only warm to cool where it has not reached. Typically on a refill
of the coolant system only 2/3 of the radiator is initially filled with
coolant. It takes me 2-3 runs around >3000 rpm to
flush the air out.
Fill up your header tank, run the
engine at 3000-4000 rpm for 30 sec or so and then see if the level of fluid in
your tank has gone down or remains the same. If it goes down (replaced
by air) then you have air in your system and I would continue this until the
coolant level does not change. Only thing I can think to advise you to
try.
Ed Anderson
Dave Leonard (still rather be working
on these issues than shaping that exit duct)
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