[Fot] TR8 Water temperature

Tue Jul 12 12:40:03 MDT 2016

Anyone ever consider an electric water pump? I don't know much about them but it seems you'd get a constant flow rate regardless of engine speed, maybe even an adjustable speed with a reostat. Plus you'd gain back lost HP. Some of our cars started life running 5 accessories on a belt (alternator, fan, smog pump, A/C compressor, and water pump). I'm down to only running the water pump off my belt, would be nice to have no belt at all!
DustyFP Spit

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-------- Original message --------From: Bill Babcock <ponobill at gmail.com> Date: 7/11/16  5:22 PM  (GMT-06:00) To: MadMarx <tr4racing at googlemail.com> Cc: fot at autox.team.net Subject: Re: [Fot] TR8 Water temperature 
Yes, outlet temperature of the block is lower, outlet temperature of the radiator is higher. Delta-T across the radiator is lower. Think of it this way, Q (heat transfer) is stable at some operating point. The excess heat from the engine is equal to the heat removed from the radiator. Ignore the heat transfer coefficient for the moment. So Q for radiator = mass x (Tin-Tout) and Q for engine is mass x (Tout-Tin). Q and M is the same for both engine and radiator and Tin of  = Tout of engine, likewise Tout of radiator = Tin of engine.
Obvious, right. So hold everything stable and increase flow rate. Obviously Tin-Tout must decrease as does Tout-Tin. The operating temperature will depend solely on the temperature drop across the radiator. If you and a lower operating temp at that Q you need a lower Tout of the radiator. 
If you increase engine load and RPM, the mass flow rate increases with RPM, but not linearly since it’s a centrifugal pump. Slip gets worse with RPM. The high flow rate system has a lower delta-t across the engine, but also has a lower delta-t across the radiator. Temperature will likely climb higher than with a lower flow rate system (depending on where you measure it, but heat transfer rate is lower, so you might reach a point where it’s inadequate to meet the engine demand. then Tout climbs quickly and shit happens. 

On Jul 11, 2016, at 2:48 PM, MadMarx <tr4racing at googlemail.com> wrote:
I think alot depends on where the system finds ist balance point.If more flow removes heat quicker from the engine maybe the outlet temperature of the block is lower?So the difference of the radiator outlet might not be so much of a problem?The water stays shorter in the block and don’t pick up that much temperature? Interesting thing to test. CheersChris Von: Bill Babcock [mailto:ponobill at gmail.com] 
Gesendet: Montag, 11. Juli 2016 23:41
An: MadMarx
Cc: Mordy Dunst; van.mulders.marcel at telenet.be; fot at autox.team.net
Betreff: Re: [Fot] TR8 Water temperature Well, you’ll need to get comfortable with a higher no-load temperature, because the radiator outlet temperature will be high.  Two factors to consider: Heat, which is the amount of energy transferred, and temperature, which relates to heat transfer only in terms of the differential temperature. Slow speed means less mass flow and therefore less heat transfer but a higher differential temperature across the radiator, high speed means more heat transfer but less differential temperature across the radiator.  On Jul 10, 2016, at 2:54 PM, MadMarx <tr4racing at googlemail.com> wrote: Hi Mordy, there are two theories about cooling and water flow. 1.      Slow speed of the water in the radiator to give the water time to cool. That means slowing down2.      The other theory sais maximizing the flow, no restriction, high coolant speed. In a way I prefer the 2nd way. And I’ll test this version in the coming weeks. I’ll remove the restrictors and see what happens. CheersChris Von: Mordy Dunst [mailto:gasket.works at gte.net] 
Gesendet: Sonntag, 10. Juli 2016 22:45
An: tr4racing at googlemail.com; van.mulders.marcel at telenet.be
Cc: fot at autox.team.net
Betreff: Re: [Fot] TR8 Water temperature Chris your the engineer....

Heat produced vs heat removed.  There will be a steady state at some point.  You would like it lower.   Don"t underestimate the headgasket component of channeling coolant flow.  In the TR4 motor i made the coolant holes different than original to allow the mass flow of water to occur from the rear of the motor forward.   I also put a pressure gauge on my coolant.  If the pressure is too low it will not cool as efficiently either.  I don"t know what the coolant  dwell time with in the head needs to be to in order to adsorb the heat generated.  Nor the dwell time in the radiator.  There certainly calcs for all this stuff.   MDunst
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  -----Original Message-----
From: MadMarx <tr4racing at googlemail.com>
To: 'Marcel Van Mulders' <van.mulders.marcel at telenet.be>; 'MadMarx' <tr4racing at googlemail.com>
Cc: fot <fot at autox.team.net>
Sent: Sat, Jul 9, 2016 8:21 pm
Subject: Re: [Fot] TR8 Water temperatureI have a 160F thermostat installed.Next test will be without any restrictions, maximum flow and see how it goes with that. Chris Von: Marcel Van Mulders [mailto:van.mulders.marcel at telenet.be] 
Gesendet: Samstag, 9. Juli 2016 13:01
An: 'MadMarx' <tr4racing at googlemail.com>
Cc: fot at autox.team.net
Betreff: RE: [Fot] TR8 Water temperature My diesel BMW runs always at 100°C/212°F when hot. What coolant thermostat is in it? If the T° is steady at 212°F, perhaps it  is intentionally done so with a 212° thermostat.Marcel Van: Fot [mailto:fot-bounces at autox.team.net] Namens MadMarx
Verzonden: donderdag 7 juli 2016 19:21
Aan: 'FOT List'
Onderwerp: [Fot] TR8 Water temperatureHi guys, My TR8 is running way too hot about 212F at full speed and at idle the temps are getting that high also. I have no idea to get them down.
Radiator core is 68x48cm x 5 cm. I suppose that should be enough. I've experiment with different restrictor plates with no change. Changing pump speed didn't help either. The difference between radiator in and outlet is 10°C (50F). Not enough I would say. Maybe making the pump more slower? It was running on a ratio of 0.8 slower than crank, currently 1:1 speed. Any ideas? 10 Liters are circulating. CheersChris_______________________________________________
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