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Re: REFLECTOR: oil temp

Simon Aegerter wrote:

> That makes sense only if the cooler is able to get rid of that heat. That
> means it has to be large enough and there has to be ample air flow. It
> seems that nobody has ever measured the airflow through our oil coolers.
> The porting of the air duct may not be ideal. The out
> port of the air duct may be too small and it may be in the wrong place.

Yes it is.  The nose of the airplane is all positive in pressure.

> Nobody seems to know. I don't. I intend to do some real measurements

Do you want to borrow my manometer?

> I have found that all measures that improved the
> airflow through the bottom of the engine compartment lowered the oil
> temperature more than anything I did to the oil cooler.

This seems to be a good argument for up draft cooling.   But we don't want to go
back to that cooling system because we know it has worked for years.  Besides,
heat doesn't rise does it?  It must fall for a plentum to work good!  High
velocity air also likes to go through ducts with a lot of corners and ridges.
Sorry for the sarcasm but this whole issue is....well I better not say any more
of  what I think.

For the bigger engines putting the oil cooler(s) to the outside of the TE wing
root with slits for air to past straight through from high to low pressure works
great for engine cooling and cabin heat.  It also cuts down cooling drag and is a
separate system from the CHT cooling.  This and a prop with a lot of cusp at the
root is probably the only way to get the high powered (more heat) tight finned
300's too cool enough to not have to step climb.