20" of water column corresponded to 16 gal/min through a 0.8" dia tube. Coolant delta T is based on measurements in my plane. Typically, I see about 10 deg F delta T at a cruise power setting.
If I remember correctly, Bill Shertz made water pump flow rate measurements with a system he set up for this purpose.
Steve Boese
From: Rotary motors in aircraft <flyrotary@lancaironline.net> on behalf of Finn Lassen finn.lassen@verizon.net <flyrotary@lancaironline.net>
Sent: Saturday, August 21, 2021 6:04 AM
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: [FlyRotary] Re: Coolant flow sensors
Thank you Steve. Exactly what I need. I can make those.
What were the approximate pressures?
On a related note, what is the 15F coolant temp deltas you mention based on?
35 gpm coolant flow cooling 180 HP?
I keep wondering where the 35 gpm comes from.
Mainly by reducing oil cooler exit air area, I'm now down to 200F @130 mph @ about 4,000' density altitude and 70F OAT. Can climb at full power to about 1,500' on a 85F day (keeping speed at 110-120 mph). Only small incremental improvements so far.. Looking
for that magic change that will lower that to 180F.
After working with air flow, I think I'll now circle back to coolant flow. Coolant delta over right rad still higher than left rad. Am thinking of hooking up a garden hose to rad inputs and see how quickly 5 gal buckets will fill up from each rad output But
35 gpm is a lot more than a garde
n hose can supply?
But flow sensors should give better real world results..
Finn