[72LuxuryLeMansLa.]

Originally Posted by PontGuy

Very few of the early Pontiacs (or any other cars) came with gages- they weren't even that common on GTOs and Firebirds. Back then as long as the idiot light stayed off and the radiator didn't boil over I was happy. It wasn't until I started doing performance mods that I added gages and started paying attention to temperature. And I bet most here did the same.

Yesterday afternoon I gave my car the "acid test" and drove it for 1/2 hour in worst-case conditions, across town with the thermometer right at 100 degrees and sunny. The engine got up to 200 in heavy traffic waiting at lights but quickly cooled back down to the 180's once there was a little open road. Living here in the SE that's about as good as I have ever been able to get with a big perf engine. If the temperature is up to 200 with a 180 deg thermostat then the cooling system is running wide open and doing all it can do, but it doesn't mean the engine is overheated. Trying to get it to stay down in the 180's is not worth worrying about.

It was way too hot yesterday to enjoy the car though. Not too bad when cruising, but sitting at lights was like being in an oven. Hard to believe now that my first few cars didn't even come with A/C but I guess we were were all tougher back in the day.

My '72 Has been stripped of most of it's AC system and it's my daily driver. I hear you on sitting at red lights in the south, it is a challenge to keep my temper in check near 100* choking on exhaust fumes.

Karl

[72LuxuryLeMansLa.]

Originally Posted by GT182

Sorry Karl but I haven't been in this thread for a time.

By overheating I mean temps upwards of 200 with a 180 thermostat. Really overheating at 220 and above. Enough so that it boils over and marks it's spot.

As I've said, up North in NY my 4 Pontiacs never had temps over 180. Even on the hottest days in the city or country. I lived in Rochester, NY from '72 to '74 with summer days in the 80s and 90s. Never saw any overheating of any sort even in traffic jams. This was with the stock original cooling system in my 66 Tempest Custom with a 326, 4bbl and ST300 trans. Even on hot days by our standards, in the 90s, up on the Canadian border of NY. My 389 4bbl 4speed 66 GTO in 1970 ran at 180. Still stock cooling all around.

I've finally realised that here in Delaware with temps in the high 90s and into the low 100s, we're gonna have a bit of a problem. So we adjust for that as best we can with a little less antifreeze and more water in the mix. Seems to work so far.

My 3 core original radiator in the GTO i have now was recored with an SLK core, still 3 rows with more tubes, 166 total, and beaucoup more fins. It still gets hot, over 180, at these darned long winded redlights, but cools back down once the car is moving again.

I got you. What we have here is a bunch of guys with different situations and equipment trying to apply fixes and chasing their tails, some of these "problems" are not actually problems but variations from temps they were used to seeing. For instance, some guys run a cooling system that came in their 200-300 HP car and have since gone up in power to the 450HP-600HP range and they are surprised that their car is running at temps over 220* . Some guys like you have moved to a different climate and are just uncomfortable with their "new" temps. In your case, it is possible that your cooling system doesn't have a new problem with it, if you had lived down south all along you may not even be bothered by the temps you are seeing.

I have a 195* thermostat in my car because that was the factory installed temp. The manual says that the engine is designed to operate at temps between 195* and 220*F. If you fill your radiator to 3" below the filler neck with a cold engine to allow for expansion of the coolant it should not spit any fluid out of the overflow. According to the manual the system will raise the boiling point of the coolant to 258*F if it is pressurized to 15PSI. If it is spitting fluid, the cap is probably bad or the system is overfilled.

Karl

[DanC]

Originally Posted by DanC

I don't understand all the concerns I've read on this site for years about 210 and 220 temps being to hot The factory thermostats, as far as I know, have always been 195, and that is just the point when the poppet is fully open.

All of my V8 Pontiac's, past and present ('68-'78, 350 - 455) have always run 210 and some up to 230 on the interstate and 180 - 210 in traffic w/ ac on. Never seemed to matter if I had a 160, 180, or 195 thermostat the 210-230 temp results were the same and I've never had a problem. But I admit I get a little concerned when it goes above 220. Yes the engines are always running cooler, even with the a/c on in stop-n-go traffic than on the interstate for me. This common occurance leads me to believe that at higher rpms the flow through the rad is too fast and does not allow enough heat exchange to take place. So IMHO I would think the wp pully diameter is where I'd start to get lower temps by slowing down the flow.

I know water boils at 212, but in a pressurized system the temp at which water boils is much higher. Which is why we have a pressure rated radiator cap.

DanC

After reading all the hype about a cast vs. stamped impeller WP I decided to experiment and try out the tricks. So I finalized the install of my Cardone Cast Impeller 8 bolt P/N58-299 Water Pump today and test drove this afternoon.

WP specs: 4-5/8 dia impeller, 11/16" vane height, .081" vane to divider plate clearance.
Outside air temp 83 w/ 96% humidity (Cooler than usual - just rained). 180* thermostat

A/C 'on' and driving 60mph coolant temp still at 212*, same results as my stamped impeller was with it's 1/8" clearance. Temp was ~180* in traffic. Temp gauge markings verified with my infared thermo gun.

Checked timing and have 14* inital & 28* w/ vac adv hooked up. 60* total @ 3600

Disclaimer: These results are not typical (as per the sticky thread 'Chalk one up'). All tests were conducted using the same vehicle under uncontrolled conditions and no other changes made other than listed above, and a JB Weld mod to close the gap on the two divider plate to timing cover water ports. No "key hole" on divider plate.

I'm glad I was never bothered by the temps, since nothing changed, but curiosity had gotten the best of me about these cast impeller and clearance claims. So this inquiring mind just had to know.

New rad/old rad, 160* thermo/180* thermo, old unknown ratio coolant/fresh 50/50 coolant, rebuilt WP/old WP, clearanced impeller/as installed impellor, cast/stamped, Good ol' gas/new poopy ethenol gas, rebuild engine/old engine, all equal same ol' "HOT" coolant for me!!!!!

So in conclusion, I am still in the same 210/220* hot water since 1978 and convinced my Pontiacs like it this way!

DanC

[Tripower455]

Mine's run at 210 since I put it on the road 6 years ago. I've tried everything I could to lower it, and nothing has changed it. I've accepted the fact that it's normal for this engine, and have gone to my happy place. I think I'm gonna remove the temp gauge altogether and complete my journey to acceptance!

[PontGuy]

There is definitely a pattern here- going back over the thread a few pages,

Fla, La, Ga- we are used to seeing temps climb up to 200 and even higher and not all that worried about it.

Wi, NJ, NY- lots of concern about temperatures riding up over the T-stat setting especially if it gets over 200 deg.

I will say that some engines seem to run better if you can keep the temperature down, so its worth doing what you can to keep them cool. But then again they all run softer in hot weather so even that may be more perception than reality.

[mchell]

what size crank and water pump pulleys are you guys running?......my sled runs a bit warm in the Florida summers, 190-220 depending on traffic etc...

I am wondering what a pulley change would do....I currently have a 7.25" crank and a 7.75" water pump pulley...so my water pump is under driven (stock pulley's)....I bet it would cool a bit better if I put a 6.1" water pump pulley on it....should get 200 rpm more at the water pump..


anyway....has any one experimented with their pulley size's??

[68 Firebird]

When I first got my car back on the road last summer I had a March alluminum pulley
setup on the car and it was an underdrive. I searched the posts and since I saved the
original pulleys I put the original crank pulley back on and it was a huge difference.

Current setup is a 7.25" pulley on crank and a 6" pulley on waterpump. I am running
3.08 gears and on a highway trip for 30 miles she hung at 190. And when i drove back roads home she went down to 175-180. I have a stock 3 row radiator(2 years old).
A high flow 160 t-stat and stock fan(direct). 11 bolt pump with stamped impeller and clearanced down to George K's post. Have upper baffles installed to direct
air to Radiator but am still missing bottom baffle. Can't find one in stock anywhere,
repro or metal!!!!

Also timing at 12 initial and 36 total. vacuum advance using ported source adding 12 degrees. 3 degrees of timing also helped as well. Carb is also dead on!

Now time for me to add a Heat shield to starter anyway. Not even a click from solenoid
until car cools down for 1/2 hour after an hour drive.(hot day 93*) Yes cables and wiring harness are new and stock logs. Anyone know a part number for the high temp solenoid??

Good Luck All!!!!!! And yes I am from Jersey!!!!!!!!!!!!!!!!

[1967Tempest]

Last week I took, the car in 85* weather on the highway. Was doing 90MPH, which is 4K in 4th gear!! and the car was right at 190*.
1:1 4th gar four speed
3:23
28" rear tire

I new that I had to get a bigger rad when I put the new gears in. More r's = more heat. The same speed above with just the 2:56's and the RPM's at 80 where 1800. The temp was thermostat.

I agree that each engine is different, but think all should run cooler than 210* if you wanted it too.


P.S. Getting rid of headers and going to manifolds, other than awesome to install, they lowered under hood temps.

P.P.S. Just got an old beat up GTO hood. Spent all day cutting out the metal and doing body work on it to make it open to the air. Once it is done, will see if temps go down further....

[DanC]

Originally Posted by mchell

what size crank and water pump pulleys are you guys running?......my sled runs a bit warm in the Florida summers, 190-220 depending on traffic etc...

I am wondering what a pulley change would do....I currently have a 7.25" crank and a 7.75" water pump pulley...so my water pump is under driven (stock pulley's)....I bet it would cool a bit better if I put a 6.1" water pump pulley on it....should get 200 rpm more at the water pump..


anyway....has any one experimented with their pulley size's??

I have an 8" crank and 6-1/4" WP pullys as measured at the overall flange diameter. I believe George K posted a reply eary on this thread about flow rate physics.

Originally Posted by 68 Firebird

When I first got my car back on the road last summer I had a March alluminum pulley
setup on the car and it was an underdrive. I searched the posts and since I saved the
original pulleys I put the original crank pulley back on and it was a huge difference.

Current setup is a 7.25" pulley on crank and a 6" pulley on waterpump. I am running
3.08 gears and on a highway trip for 30 miles she hung at 190. And when i drove back roads home she went down to 175-180. I have a stock 3 row radiator(2 years old).
A high flow 160 t-stat and stock fan(direct). 11 bolt pump with stamped impeller and clearanced down to George K's post. Have upper baffles installed to direct
air to Radiator but am still missing bottom baffle. Can't find one in stock anywhere,
repro or metal!!!!

Also timing at 12 initial and 36 total. vacuum advance using ported source adding 12 degrees. 3 degrees of timing also helped as well. Carb is also dead on!

Now time for me to add a Heat shield to starter anyway. Not even a click from solenoid
until car cools down for 1/2 hour after an hour drive.(hot day 93*) Yes cables and wiring harness are new and stock logs. Anyone know a part number for the high temp solenoid??

Good Luck All!!!!!! And yes I am from Jersey!!!!!!!!!!!!!!!!

I have the same stock pullys if you are measuring the grooves, a 180* fail safe thermostat, 18 y.o. 4 row rad which as been rodded out once with one tube closed off, NOS fan shroud, HD thermo clutch stock fan ( clutch works, as you can diffenately hear the differance when it locks ), 2.78 gear, 25-1/2" dia tire, TH350 trans, stock 350 w/ Q-Jet, 14* intial timing w/ manifold vac adv bring it up to 28* at idle, and the upper and lower metal baffles as this is an orig A/C Firebird.

As far as the Hot Start problem you have, I have had great success with the Ford style remote setup. I install these on all my Pontiacs. The first one I had to do, '71 455HO with the HO exhaust manifolds. The heat shield thickness was practicley the gap between the starter and manifold to headpipe connection! I do not buy the kits but rather build my own and with the TA, GTO and GP was able to hide them either in the fender beside the battery or between the batt and core support on the GP. My diagram attached below.

Originally Posted by Tripower455

Mine's run at 210 since I put it on the road 6 years ago. I've tried everything I could to lower it, and nothing has changed it. I've accepted the fact that it's normal for this engine, and have gone to my happy place. I think I'm gonna remove the temp gauge altogether and complete my journey to acceptance!

I like that idea!

[1967Tempest]

Originally Posted by HWYSTR455

True to a degree about 'boiling off' moisture and other contaminants from oil, but oil temps get way hotter than coolant temps, and it will reach the required temps with a 160 stat, just takes longer.

The wagon got its oil changed today. was looking into the valve cover. White milky oil. Just rained and the engine condensated sitting in garage. With the car running at t-stat of 160*, took 30~minutes @ idle, but then was nice and golden brown. So the water cooked right out.

That was my first real experience watching the water come out of oil. Cool......

[Formulabruce]

Originally Posted by 1967Tempest

The wagon got its oil changed today. was looking into the valve cover. White milky oil. Just rained and the engine condensated sitting in garage. With the car running at t-stat of 160*, took 30~minutes @ idle, but then was nice and golden brown. So the water cooked right out.

That was my first real experience watching the water come out of oil. Cool......

I tend to see this more on old motors where compression is weaker and crankcase pressure is up a bit.

[DanC]

Drove to a Veterans Benefit Show at the Battleship Park in Mobile AL yesterday.

In the cool morning on the two hour, 70 mph interstate drive over there my temp was around 210. (two hour drive)

On the way back in high 80' outside temps with the a/c on to Pensacola my water temp was just below 250 My temp needle was just 'touching' the low side of the 250' hash mark. I experianced no pinging or power loss and my "idiot" light never illuminated. (one hour drive)

From Pensacola back to home on the interstate again it was cool outside and no a/c, my 70 mph temp was 210. (one hour drive)

I must admit I never had seen my temp this high before ever, but I was waiting to see what bad may happen, but nothing did.

So much for my recent "clearanced" cast water pump install for me. I'm putting my stamped impeller back one!!!

My of my experiance. Can't explain it, just tellin' ya like it is.

DanC

[Formulabruce]

Originally Posted by DanC

Drove to a Veterans Benefit Show at the Battleship Park in Mobile AL yesterday.

In the cool morning on the two hour, 70 mph interstate drive over there my temp was around 210. (two hour drive)

On the way back in high 80' outside temps with the a/c on to Pensacola my water temp was just below 250 My temp needle was just 'touching' the low side of the 250' hash mark. I experianced no pinging or power loss and my "idiot" light never illuminated. (one hour drive)

From Pensacola back to home on the interstate again it was cool outside and no a/c, my 70 mph temp was 210. (one hour drive)

I must admit I never had seen my temp this high before ever, but I was waiting to see what bad may happen, but nothing did.

So much for my recent "clearanced" cast water pump install for me. I'm putting my stamped impeller back one!!!

My of my experiance. Can't explain it, just tellin' ya like it is.

DanC

Alcohol did it... BUT I would love to know what the IR temp is at the T stat housing ( Infrared) Pocket IR thermometers are under 25 bucks!
http://controlscentral.com/eCatalog/...3/Default.aspx