[Fot] TR8 Water temperature

Wed Jul 13 07:28:07 MDT 2016

I looked into at one time, for exactly those reasons.  I knew an 
autocrosser in St. Louis
who had done that on his home built open wheel car, but eventually 
decided not to
go that route.  I can't remember why though - possibly just lazy... 

John

On Tue, 12 Jul 2016 13:40:03 -0500, Dustin Nicholson  wrote:

       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!

Dusty
FP Spit

Sent from my T-Mobile 4G LTE Device

-------- Original message --------
From: Bill Babcock

Date: 7/11/16 5:22 PM (GMT-06:00)
To: MadMarx
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  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. 

Cheers 
Chris 

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  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 down 
2.      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. 

Cheers 
Chris 

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
Headgasket.com
626.628.3777 F
Triple R Munitions, Inc
626.201.9471 T
FFL 6,7 SOT 2

-----Original Message-----
From: MadMarx
To: 'Marcel Van Mulders' ; 'MadMarx'
Cc: fot
Sent: Sat, Jul 9, 2016 8:21 pm
Subject: Re: [Fot] TR8 Water temperature

I 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'
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 temperature 
Hi 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. 

Cheers 
Chris 
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Thanks,
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