Ok now comes the tricky question...... Green coolant ..or..Orange coolant..? Or make that the psycodelic question. What cools better in our situation? David Cook RV6A Rotary.
----- Original Message -----
From: "Lynn Hanover" <lehanover@gmail.com>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Sent: Tuesday, August 18, 2009 12:40:00 PM GMT -05:00 US/Canada Eastern
Subject: [FlyRotary] Swirl pots (soap)
I believe adding dish soap or water wetter is supposed to reduce surface tension between coolant and block.
What is the measured net benefit of either additive? 1%-5% improved cooling?
Jeff
The temperature differential between the radiator tubes and the coolant tend to cause detris to collect on the tube surface, and insulate the tube from the coolant. So, the radiator never performs as well as it will the first week you run it. Also, cooler coolant tends to cling to the tube, and hotter coolant tends to flow down the center of the tube.
Good radiators have dents or creases criss crossing on the tube walls to improve turbulance in the coolant in an effort to keep the insulating cooler water off of the tube walls and improve overall cooling performance. The surfactants help move the coolant, by destroying the surface tension of the water. Why this works escapes me. But more slippery does sound better, right?
The added benifit is a cleaner radiator tube and block interior. That has to help as well.
The down side is that those same surficants can foam the coolant should coolant levels be come very low.
If you stop by the radiator shop and look at some old cores you will use wetting agent and distilled water in your engine.
It is too often the case that just a few more seconds of engine power, makes the difference between a really great airplane story, and a very sad airplane story.
Lynn E. Hanover