In a message dated 10/23/2007 6:35:54 P.M. Eastern Daylight Time,
bbradburry@bellsouth.net writes:
Apparently I am not
getting enough fuel flow to support high rpm. I have not done the self
tuning at high rpm yet, but I would not expect that the fuel flow would be so
low as to limit the rpm.
What suggestions do
you have? My ability to self tune has been limited due to cooling
issues…especially at WOT!
Lynn, it is too early to
be sure yet, but your idea for the pressure bottle looks like it is going to
help the cooling a lot. It may not be the complete solution, but it
seems to be a step in the right direction.
Thanks!
Bill B
The rotary can run over-lean or over-rich happily. (sounds good and strong
both ways, and doesn't miss).
Over rich can be right up to black smoke pouring out of the exhaust. It
shows as very low EGTs and water temps. I have been unable to make one shut down
from being too rich.
Over-lean sounds a bit more crisp, has much less power, just slightly low
coolant temps and EGTs slightly low than normal. If leaned too far (ignition
system will no longer light the mixture) the engine will shut off sharply, and
will spool to a stop even at full throttle. But that is way lean of peak EGT.
This is the case with peripheral exhaust ports. I don't know how the new side
exhaust port runs when over lean.
Sudden over heating at full throttle, is usually air in the system that has
stopped the pump or a lack of coolant in one location. So, the pressure bottle
works great for eliminating that.
A long steady climb to overheating, shows you an undersized (under
performing) cooling system. Needs better sealing around coolers. Bigger coolers.
More airflow.
EGTs are controlled by running just slightly rich of best power, or
50 to 100 degrees rich of peak EGT or below 1650 continuous for carbon
seals, maybe 1700 for steel seals and it makes no difference for ceramic
seals. Once at cruise, depending on how fast you want to go, you can lean well
past peak EGT to get the EGT back down. Even 100 to 150 degrees below peak, or
more with tight plug gaps and a good ignition system.
Lynn E. Hanover