From: "Finn Lassen finn.lassen@verizon.net" <flyrotary@lancaironline.net>
Received-SPF: pass
 receiver=logan.com; client-ip=66.163.190.33; envelope-from=finn.lassen@verizon.net
Subject: Re: [FlyRotary] Re: Renesis coolant flow measurements
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
References: <list-746377@logan.com>
Message-ID: <4c42ab0e-0bbc-d023-d71f-8259962aa94e@verizon.net>
Date: Fri, 4 Mar 2022 20:36:37 -0500
User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:52.0) Gecko/20100101
 Thunderbird/52.9.1
MIME-Version: 1.0
In-Reply-To: <list-746377@logan.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit
Content-Language: en-US
Content-Length: 3209

On 3/4/2022 2:10 PM, Charlie England ceengland7@gmail.com wrote:
> On 3/4/2022 11:43 AM, Finn Lassen finn.lassen@verizon.net wrote:
>> Got my "Save a Drop" water meter in the mail yesterday. Unfortunately 
>> it only shows accumulated flows and no gal/minute mode. That means I 
>> could not insert them in the running engine system to measure flow 
>> rate there.
>>
>> Claims +/- 1.3% at 6 gal/min, 70 psi and 68 deg F. Max pressure 116 
>> psi. (Sounds like there is a rotating "wheel" inside when water flows.)
>>
>> So I did two one-minute runs that gave 18.1 and 18.5 gal/min (varies 
>> by pump pressure as you can see from the calibration spreadsheet). 
>> But the calculated flow rate in the spreadsheet (in zip file) comes 
>> out to about 16 gal/min average.
>>
>> For some reason the 0.807" ID homemade flow sensors (with 1/16" OD 
>> pitot and static tubes) appear to produce lower pressures than 
>> predicted by the formula referenced in earlier recent posts. I 
>> calibrated the differential pressure sensors I use (MPX10) with a 
>> water manometer, so I'm fairly sure that my measured inches of H2O 
>> (head?) pressures are accurate within a couple percent.
>>
>> That means that the Renesis total flow (see the other attached 
>> spreadsheet) could be as much as 12% higher or 53 gal/min at 4,800 
>> engine RPM.
>>
>> Again, I have two radiators in parallel, with as low as 1/2" ID 
>> restrictions in fittings and welded tubes.
>>
>> Calibrations were done with pure water. Engine (system) runs with 
>> 50/50 antifreeze. At running temps (180+ F) the specific heat 
>> difference should be about 12% (only changing the 0.186 to 0.203 in 
>> the spreadsheet formulas).
>>
>> What I don't know and hope one of the experts here (Steve Boese) can 
>> clarify is if zero system pressure (calibration flow of water 
>> emptying into the air) vs system pressure (varies with RPM and temps; 
>> couple of psi to as much as 8 psi in some of the runs) in the engine 
>> runs would make a difference.
>>
>> In any case I'm now fairly sure that coolant flow rate and flow 
>> balance between the two rads is not a factor in my cooling issues.
>>
>> Finn
> Any particular reason for staying with 50/50 mix? Most of the 
> antifreeze mfgrs seem to say that around 1/3 antifreeze is enough for 
> corrosion protection, so you'd get slight improvement in heat carrying 
> ability from the coolant. If you live where it rarely gets colder than 
> around 0*F, the charts look like 30-35% is more than adequate. IIRC, 
> Lynn H has talked about running pure water with a few drops of 
> detergent functioning as 'water wetter'.
>
> I'm having a bit of an 'oldtimers' moment, but I have a vague memory 
> about closed loop pumping systems being more efficient in flow, but as 
> I said, the memory is pretty fuzzy.
>
> Charlie
>
Comes 50/50 from Walmart :) Do know if that's by volume or weight.

I guess the main reason to keep it that way is to ensure the high 
boiling point. I have no idea what temperatures the coolant actually 
sees on coolant passage walls in the engine. But probably a good idea to 
dilute it with some distilled water. We very rarely see anything like 
20F to 25F  here.

Finn