As you said, fuel pooling is a problem even for injected engines. So you see water heated manifolds, just as in carbureted  engines. Note the Lycoming with the distribution pot inside the oil pan. Heated oil keeps the mixture in a gas like state and the latent heat of evaporation helps cool the oil. On hot days there is a loss of power based on intake air temperature, but they suffer fewer carb icing events.

 

Injectors do a better job of cooling the intake tubes close by, and absent some warming agent, some condensation will return to the fuel. 

At the least at lower power settings. So Mazda would appear to have moved the injector to the housing so that the fuel spray is facing the 300 degree plus rotor face. Plenty of heat to maintain a gas like state. So the rotor face is cooled some by the fuel. And thus a cooler oil in the rotor. There is no power loss because the chamber is closed and incoming air was not heated prior to entry so density was not lost.

 

Lower rotor face temps allow for more intake to enter, and thus more power.

 

The injector is firing into a low pressure unless turbo charging is involved. I am unable to detect a downside to this layout.

 

An idle at 2000 RPM can be tolerated, to protect reduction gears.

The racer idles between 2000 and 2200 RPM. So one big injector might do just fine, even if idle is less than ideal.

 

Lynn E. Hanover

 

 

 

In a message dated 7/27/2011 2:00:15 P.M. Paraguay Standard Time, echristley@nc.rr.com writes:

The MegaSquirt can time the injection based off of the ignition timing. 
I'm having some issues with my manifold.  The way I built it is causing
fuel to puddle in the bottom (so, you live, learn and rebuild).  I can
probably move the two fuel injectors to the oil injection ports easier
than I can build a new manifold.  The other two injectors are at the
stock position in the center plate.  Then I would tune the fuel injector
timing to minimize EGT.

Am I fooling myself?  And, if so, how?