I am using Evans(boils at 400F) and small lines with two radiators in series. The oil rad is the Mazda car rad. This is Rusty's design for the RV-3 and it works very well. On 85 degree day on a WOT climb to 5000' the water temp gets to 175 and oil to 185. Cruse at that altitude usually results in 135 to 145F.
----- Original Message ----
From: al p wick <alwick@juno.com>
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Sent: Friday, January 5, 2007 10:20:41 AM
Subject: [FlyRotary] Re: Ideal cooling
Trying to make an inadequate cooling system functional by using a different coolant is simply not going to work, but people keep trying. If pure water is not doing the job, then using liquids with a lower heat specific is only going to make it worst.
The Egg guys have been very successful using the Evans coolant. The fluid is less efficient, so it inflates the operating temperature. But it also brings a new very high boiling point to the party. So instead of operating at the normal 200F temp, they operate at 215F. But the boil over temp is way up there...I forget, but something like 260F or so. As a result, they end up with greater safety margin. A very sound decision for their installation. This because boil over is sudden, catastrophic, and essentially irreversible. When it blows, it blows.
Rumor has it that the same solution on your engine would not add safety margin, but actually reduce it. I'm skeptical of that personally, but don't have facts to evaluate. It just sounds fishy that there are components so sensitive to a mere 15F change in temp. I know how these theories can get started and hang around for lack of facts. So I don't know one way or the other, just skeptical.
But here's the cool thing. We tend to think along the lines of "What can I do to improve cooling? What can I do?" But this Evans brings a new tool to the party. It's a great way to determine if you have flow volume problem. If you have inadequate coolant flow, Evans dramatically negatively effects you cooling. I've measured, logged, and tested tons of cooling concepts. Deliberately overheating engine, stuff like that. Tracy's data strongly suggests local boiling. (Bills? observation). Trapped air or low flow are leading causes. I strongly suspect low flow due to line restrictions. I think we've got lot's of guys operating with 70% less flow than the engine normally sees, and that puts them right on the edge of this problem.
FWIW.