What temperature does your roadster run at?

Bungle · Post by **Bungle** » Wed Jun 01, 2005 5:38 pm

Just throwing a general question out there to you guys regarding running temp.

What temp does your car run around town? Out on the highway? What model have you got?

Just trying to see what the average is and find out what's normal...

Mine's at around 180-190 around town, and up to 225 on the highway...

eastmedia · Post by **eastmedia** » Wed Jun 01, 2005 6:44 pm

around town 175-180, highway 195-200.
69 1600, 2000 radiator.

Post by **dbrick** » Wed Jun 01, 2005 11:25 pm

That seems odd to me, hotter on the highway with maximum airflow? Normally if all is well highway cruising should be right about at the thermostat temperature, excluding really high air temperature or excessive engine load, while sitting in traffic is where you would heat up.

Wonder if the engine fan is actually hurting airflow at that speed?

By the way, anyone have any data how accurate the factory gauge really is?

Bungle · Post by **Bungle** » Wed Jun 01, 2005 11:37 pm

I agree. Other old cars I've had have run cooler on the highway. I'm thinking/hoping that my radiator is partially clogged. It is a bit revvy on the highway though without overdrive. As for the accuracy of the temp gauge... I haven't tested mine against anything, but my car did boil over when it was registering 250 in summer pre water pump replacement and carb rebuild...

The difference with mine is that I run a thermofan. It's basically on all the time! It's interesting to know though that the roadster with the conventional fan behaves in the same way, albeit running a bit cooler than mine...

Post by **dbrick** » Wed Jun 01, 2005 11:44 pm

You run the electric all the time? What about your thermostat, what temperature?

Bungle · Post by **Bungle** » Wed Jun 01, 2005 11:50 pm

Yeah I bought the car with the thermofan already installed and hardwired to the ignition. It runs all the time (which is a real pain) but I haven't got around to installing the thermo switch yet. If I did it would run constantly anyway!

I believe my thermostat is 160 degrees.

spyder · Post by **spyder** » Thu Jun 02, 2005 12:54 am

I had overheating problems with one of those 7 blade plastic fans and no clutch. Took the radiator out to have cleaned and they said it was shot and so it was recored. Ran cool in south Texas but the fan made much noise at high rpm. "Ill remove noisy fan and install electric puller fan!" In summer it would go to about mid gauge and climb up very high under full throttle. Removed electric fan and put in a stainless flex fan from summit or jegs and now it never strays above the first third of the gauge.

Bungle · Post by **Bungle** » Thu Jun 02, 2005 1:35 am

Sounds like the electric fan may be contributing to the problem. Getting the radiator rodded for $70AUD, I may buy a flex fan too... (the electric fan pulls a lot of current anyway...)

Do you still have the shroud with yours?

SER240Z · Post by **SER240Z** » Thu Jun 02, 2005 4:02 am

Mine runs just over the 120 mark consistently.

Scott

Redtail · Post by **Redtail** » Thu Jun 02, 2005 12:48 pm

Is there a problem with running too cool all the time? about what temperature should they run at? My 1600 runs around 170 consistantly.

nomadtrash · Post by **nomadtrash** » Thu Jun 02, 2005 3:17 pm

Roadsters like to run at 200. My race car ran at 200 with several different radiators, mechanical, and electric fans with and without fan shrouds. It didn't start running at less than 200 until I put in the KA24DE. With the identical radiator and electric fan that ran at 200 on the U20 I get 180 on the KA. Actually, the temp fluctuates on the KA from 160 to 180 when the thermostat opens.

I wouldn't be too concerned with running at 200. Make sure to use oil that works with that temperature range. If you start running much higher then you may have a problem. Always use a fan shroud. The fan is almost useless without one.

Later,

jbush · Post by **jbush** » Thu Jun 02, 2005 7:29 pm

My '67 1600 (no fan shroud) runs 170 to 190 usually - got to 210 in the Mojave in August. My '66 2L (shrouded fan) hasn't gotten above 130 yet. I don't know if the '66 has a 2L radiator or the original 1600 one, but regardless, I agree with Andy - a shroud makes a big difference.

JoeK · Post by **JoeK** » Thu Jun 02, 2005 8:58 pm

My '68 2L has never gotten past 120 on the gauge. Tomorrow I'll be installinga new temp sender, hopefully that'll give me some good readings.

Bungle · Post by **Bungle** » Thu Jun 02, 2005 11:46 pm

Shouldn't a roadster - or any vehicle for that matter run at or close to the temperature that the thermostat opens at? (ie for mine it should be about 170 - but I get 200). Isn't that what the idea is all about? Doesn't the thermostat opening temperature reflect what the ideal operating temperature of the engine should be? That's what I've always believed to be the case. I suppose the gradual opening of the thermostat over a temperature range (ie. 170 to max lift at 200 for the 1600 R series) could throw a spanner in the works of this theory...

I may be off the mark here but if a roadster was meant to run hotter than what the thermostat opens at, then ambient temperature would thus play a far greater role than what it should... ie. the radiator should be efficient enough to keep the motor on a constant cooling trend (to a point below that of the thermostat opening temp.) regardless of the ambient temperature (ambient will only ever realistically get to say 110).

For those who are running consistently at temperatures lower (ie. 120, 130) than the thermostats designed opening temperature (170 for the R16 & U20, 160 for the G15) thus must either not have a thermostat installed, or it or the temp. sending unit is malfunctioning...?

Ok invitations are open to shoot my current knowledge/theory down in flames....

Post by **dbrick** » Fri Jun 03, 2005 12:18 am

I'm with you, John. As far as I ever learned the thermostat is designed to regulate the minimum operating temperature of a warmed up, properly tuned engine. If you are running substantially above thermostat temp in "normal " ambient temperature you are either making too much heat, retarded ignition, excessive lean mixture, etc or not conveying enough heat to the outside, plugged radiator, bad pump, clogged block.

Now for the info I have found to be true.
1 a car without a thermostat may run hotter at high engine speed due to coolant traveling too fast through the system and not properly transferring the heat than the same car with a thermostat.

2 believe it or not, cars will run cooler on pure water (with an antirust agent) than they will on 50/50 water/ethylene glycol. Water transferrs heat bettet than antifreeze. But, the water has a lower boiling point, so this may just be usless trivia.

3 a fan can add to an overheating problem at high speed by screwing up the airflow and it also draws horsepower, which creates more heat.

4 If you change from a 180 degree thermostat to a 160 degree thermostat, your operating temperature should also drop proportionally. If it does not, your cooling system is undersized or not efficient.

5 Cars now run 190 degree thermostats for emmissions reasons, I think it reduces NOX, but not 100% sure, and because at that particular temperature, cylinder wall wear is the lowest, it wears more at higher and lower temps, much worse hotter than colder. People put in 160 degree thermostats in computer controlled cars to fool the computer into thinking it is not warmed up and richening the mixture.
But, at 190, pinging is a bigger danger in a carbureted carwith no knock sensor.

6 I'm adding a second temp gauge and manual fan switch. I have no belt driven fan, rely on electric with temp sensor. May also add small belt driven fan, will see how it is in traffic.

7 three or more people cannot agree on automotive theory.