Lynn,

 

Thanks for the excellent lesson on oils and oil cooling.  I'm optimistic that my oil temps will come down substantially with the new oil cooler.  Ground running has been encouraging.

 

What do you consider an optimum temperature for the water?

 

Mark S. 

 

From 160 to 180 is just fine. When drafting you can go to 200 but then you have to short shift a bit or duck out into the airstream for a second, now and then. 

 

Oil temps from 160 (ideal) to 200 are OK. The racer is stressing the oil quite a bit harder than the airplane with a typical 6,500 RPM. That would be about 170 to 180 HP for a side port engine or 190 to 210 HP for a periphery port engine. A great side port 12A can do 275 HP at 10,000 RPM and a Periphery port 12A can do 310 HP at 10,000 RPM.  

Once an installation has prooved the engine is assembled properly, all that is left is the support systems to provide anvil like reliability. The engine is under very little stress at 6,500 RPM and full throttle. The engine can cool 120 HP per housing with no drama at all.

 

Hp at 6,500 for my engines is 173.3 at 12.3 F/A and .666 BSFC. That is a full "J" bridgeport with an intake tuned for 9,000 RPM (very short). This with an intake restricted to two 36MM chokes.

 

This data point is used to build a full power curve. The engine is not used below about 7,800 RPM, or 229.4 HP.

 

On take off you should be able to exceed the airframe structual red line while still over airport property.  

 

How can you screw this up?

 

Lynn E. Hanover

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