[FrankieT/A]

Originally Posted by Region Warrior

Don't listen to anyone that says 210 is to hot.
That's what they ran from the factory.
Think GM didn't know what they where doing?
The more heat an engine can tolerate, the more power it will make.
Anyone that says opposite doesn't know thermodynamics.
If it pings, theres a problem with the tune and/or fuel.

Region Warrior is 100% on the mark!!! Pontiacs do run too close the border of the over heating they withstand in my opinion. Some engines can get seriously over heated and be fine after cool down. Pontiacs are not one of those engines! Pontiacs do not like to be overheated. For one thing as an example, Pontiacs have four head bolts per cylinder whereas Chevys have five. IIRC Chevys also have more bore spacing which gives more deck surface area between cylinders which obviously gives more head gasket contact area. Hotter engines make more power and are more energy efficient, and that is a fact. Problem is with Pontiac that starts to approach the catastropy point. At the expense of power and efficiency I like my cars to as cool as possible because I like the cushion. I like my cars to run as far below 200* as possible. It makes me feel better. Predetonation is a matter of tune, but so is hi compression. Low compression low performance engines do by virtue run cooler.
So how hot is too hot? Depends on a lot of things.

[rexs73gto]

Reigion warrior must be a kid , because there were no Pontiac's in our years that came from the factory that ran at 210 dg.'s. If it did it would have went right back in to be repaired. Our year cars were ment to run at 180 deg.'s & maost everyone in my day put in a 160 or 165 T-stat so they could cruise all night without their car getting hot & having to pull over & stop. The only time Pontiac made cars to run anywhere close to that was from the late 80's when they started to use computer in the cars & then it was for emmissions & not real world performance. If you had a car that ran that hot we started to look for broken parts when they were brought into the dealership for service. Plue the 195 deg. T-stat wasn't even available for use in our cars when they were new. The T-stat that was in my 73 GTO when I bought it new was a 180 deg. & that was to much when we started to run them hard as they got TO HOT very fast. So before you start saying it was made that way , please check all your facts against real world usage first.

[A.J.]

Hmm, this seems to be a sensitive subject?
To the help the threadstarter sort this out I would say he would start checking the simple things
1. Confirm that the gauge reads ok
2. Service the engine, see to that the timing and vaccum advance is working and correct. Check for vaccum leaks, check the sparkplugs. Check the thermoclutch by spinning the fan by hand. It should not continue to turn by itselft more than 1/4 turn if its good. Are the hooses ok and do you have the spiral protecting the lower cooler hose from collapse?
3. Also see to that the carb is adjusted/calibrated.

If all checks out OK but the temp still is high its time too look at what type of faan tou have, waterpump cast or stamped impeller, waterpump mod.

How is the compression of the engine?


I'm no expert and I just been walking a year when the car in question was made but the above makes logic for me and any comments to the above is appreciated

[Region Warrior]

Ok, simmer down
Didn't mean to get ugly. This topic comes up every year since the 70's(for me).
Grew up in new 60's/70's Pontiacs and 1st car was a 68 FB from 75-82, and have a 67 since 79.
All my buddies had muscle cars. They all ran over 200*.

Been to Arizona(brother inlaw lives in Phoenix). And Death Valley in 65. Never forget it.
7 of us in a month old 65 Bonny full of luggage and A/C full blast. 115* out at the time, dad was concerned cause temp gauge was pegged most of the trip.
Us kids where complaining how cold it was in the car. After 5-10 minutes of it, he pulled over and made us get out for 10 minutes(felt lot longer lol) while he and mom in the idling car stay'n cool.

Wouldn't necesarly call 11.70-12.00 @ 114 mph with 3.42's on 87 octane in 95* heat detuned. And also drove it 70 mph plus for 20 miles in 95* heat more then once.
Most guys think its overheating when radiator over flows.
Cause is usually aftermarket stuff and/or missing factory stuff.
Or radiator full to cap when cold which is incorrect. should be 1.5"-2" below.
Don't take this wrong. But since you dont believe they ran that hot back in the day, check 60/70's factory service manuals and road test articles from the 60's and 70's.

[Region Warrior]

Originally Posted by rexs73gto

Reigion warrior must be a kid , because there were no Pontiac's in our years that came from the factory that ran at 210 dg.'s. If it did it would have went right back in to be repaired. Our year cars were ment to run at 180 deg.'s & maost everyone in my day put in a 160 or 165 T-stat so they could cruise all night without their car getting hot & having to pull over & stop. The only time Pontiac made cars to run anywhere close to that was from the late 80's when they started to use computer in the cars & then it was for emmissions & not real world performance. If you had a car that ran that hot we started to look for broken parts when they were brought into the dealership for service. Plue the 195 deg. T-stat wasn't even available for use in our cars when they were new. The T-stat that was in my 73 GTO when I bought it new was a 180 deg. & that was to much when we started to run them hard as they got TO HOT very fast. So before you start saying it was made that way , please check all your facts against real world usage first.

Funny you say kid since your wrong on several points.
Not gon'a point'm out, but if their meant to run 180, why did Pontiac only install 195* stats all models from 66 and up?
Have you ever replaced an original stat?
If it was anything less then 195, wasn't original.

[importsmasher]

Pretty much every Pontiac I have ever owned ran around 210 degrees. My 66 GTO convertible ran 240+ all day long in the Arizona heat until I put in an aluminum radiator. I ran it like that as a daily driver for many years and the engine has almost 100,000 miles on it since rebuild, still running strong, with no issues from running hot (it's not nearly as hot here in Utah, and it runs 210 with the aluminum radiator). Not Pontiac, but my brother has a 69 GS that he ran a 430 with A/C as his daily driver for at least 8 years that also ran 230-240 all day long. He has since replaced the engine, but only because he wanted a correct 400 in it. Even the 62 LeMans I had with the aluminum Buick V8 ran 200-210.

I don't give anything under 230 a second thought. That being said, the engine I just built for my 73 Formula seems to stay in the 190s...

Flame on....

Importsmasher

[rexs73gto]

I've had 27 GTO's 5 firesbirds & 3 T/A's & none of them ever ran close to that high 230-240 temp. The one that runs the hottest is my 73 GTO with a 461 in it & it runs at about 190. If it were to get any higher I'd be looking at a problem. My 73 when new (bought new) ran at 180 from day one & never got anywhere near the 230 mark. When I changed the original t-stat it had a 180 in it from the factory. The car came with HD cooloing a 400 & auto with the original rear end being a 3:08. If that one ever got close to 200 I'd know it had a problem. The older cab cars should not run any where near 200 ever. They are not designed to do that. I just looked in my parts book & the t-stat that belongs in my car is a 180 deg. NOT a 195 as you have stated. Not all Pontiacs came with a 195 t-stat as you have said. The cars with HD cooloing came with a 180 deg. t-stat from the factory as to keep the temps down so if they did do some hauling it had a chance to go up SLIGHTLY but it was ment to run at 180deg.'s.

[judgeman6970]

I think "preferred engine temps" vary as much as "which oil is best for my car" opinions. With that being said, I think the cooler the better. I almost always run a 160 stat(180 at the most), and my cars very rarely hit 190 degrees. I've never done any "wear tests" on them, but they've always run well, and even start easier when hot...works for me!!

[Chris65LeMans]

Originally Posted by A.J.

Hmm, this seems to be a sensitive subject?

It definitely is. I'm new to Pontiacs, but talk to a lot of the Pontiac guys at shows. Opinions run from both sides of the spectrum; from "My car runs at 160 going through Death Valley at 110 mph and 120 degree heat with the A/C on" all the way to "sure, it gets up to 235 at stoplights, but drops again when I start moving."

Mine will see 220 occasionally in stop and go traffic if I start lugging the engine (I've got an M21 and am trying to break my habit of using too high a gear at low speeds.) As long as it gets below 200 once I start moving again, and doesn't rise above 230-ish; I'm happy. I run this past Pontiac guys, and never hear any alarms.

I see guys on here all the time throwing money and time at their car so that their temp needle NEVER moves off 190; and I'm not sure that's a realistic goal. (particularly on a car that came stock with a 195 'stat.) There's always other car stuff that time and money can be used on.

The owners' manual only had one line about heat. Something like "if it ever gets above 245, shut it down and see what's wrong."

[FrankieT/A]

Originally Posted by Chris65LeMans

It definitely is. I'm new to Pontiacs, but talk to a lot of the Pontiac guys at shows. Opinions run from both sides of the spectrum; from "My car runs at 160 going through Death Valley at 110 mph and 120 degree heat with the A/C on" all the way to "sure, it gets up to 235 at stoplights, but drops again when I start moving."

Mine will see 220 occasionally in stop and go traffic if I start lugging the engine (I've got an M21 and am trying to break my habit of using too high a gear at low speeds.) As long as it gets below 200 once I start moving again, and doesn't rise above 230-ish; I'm happy. I run this past Pontiac guys, and never hear any alarms.

I see guys on here all the time throwing money and time at their car so that their temp needle NEVER moves off 190; and I'm not sure that's a realistic goal. (particularly on a car that came stock with a 195 'stat.) There's always other car stuff that time and money can be used on.

The owners' manual only had one line about heat. Something like "if it ever gets above 245, shut it down and see what's wrong."

My car sees thousand mile trips(last one was two weeks ago 2000 miles round trip)and the last thing I want is a blown head gasket far from home. So, yeah, I need that comfort zone!

[rexs73gto]

My 73 has been running a bit hot of late & just this week I tore it down & put in a new water pump. I was running at or about 200-205 while in traffic & a little higher when at a stop. That has been the way it's run since I put in the new engine. I now have a 461 in my car & with it running hot like that I thought it was because it was a brand new engine. But no , there was something else going on so I pulled it apart & clearenced the divider plate to somewhere between 25-30ths. as it's very hard to get an excact measurement on the fins of the blade with the plate in place. I have it all bace together now & took it for a drive yesterday. I forgot to say I put in a 160 deg. T-stat too, it now runs in between 170-175 degs. while sitting or driving now. Thats where it should run no higher if you want them to last. I forgot to clearence the divider plate the last time & I think that was my biggest problem , but it runs where it should now. For all who are having any cooling problems don't do as I did & forget to clearence that diviver plate it is a must to do on our Pontiacs to make them run where they should.

[GTOGreg]

Originally Posted by Pontirag

I'm not the only person running pontiacs in the arizona summer time who scratch thier heads wondering why others in much cooler parts of the country have all these overheating problems, GM them selves never did either and no they never had thses cars running all day long at 210 degrees.

But it's a dry heat (somebody had to say it)

[FrankieT/A]

Originally Posted by GTOGreg

But it's a dry heat (somebody had to say it)

I already did, post 34.

[GT182]

Get an infrared temp gun from Harbor Freight or some other place. That will tell if your thermostat is right or wrong. Even helps find hot spots in your engine.

The 66 GTOs came out of the factory with 190° thermostats in them. My 66 Tempest Custom and 63 GP both had a 190 in them. They all ran at 190. Other Pontiac models probably had 190s too. Remember.... back then gas was real gas, cheap, and we ran the snot out of our cars. Unlike today they were our daily drivers.

210°s is borderline too hot IMO. Shouldn't run that hot but if it does a lot, something is not right. My 66 GTO, 66 Tempest Custom, and the 63 GP I owned back in the 70s never overheated unless something was wrong with the cooling system. Usually it was the t-stat or water pump, or bad antifreeze loaded with crap in it. And that's why Pontiac recommended changing the antifreeze every 24,000 miles or so. And I think the manufacturers still do.

[Region Warrior]

Thing is 210 is not over heating. Yes, hotter then most like.
According to Pontiac back then, 245(?) was. Have to find my old service manual.
Even though i say its ok, mine's 190-200 at idle cause runs fastest in 1/4 mile. Even when its in the 90's. It's a tuning thing i guess.
Remember, don't fill radiator to cap when cold. Leave about 1.5" space.

[rexs73gto]

On the older then 69 cars yes you have to leave the coolant down to at about an inch & half low in the raditor but if you do that on the cars that have the over flow tanks so it can purge & refill the way it was designed you will run hot as it doesn't have enough coolant to recycle it through the system as it should. If it's got the over flow tank & your 1 1/2 inch low your about a half gallon low in coolant just to start & that to will cause it to get hot to.

[DanC]

Not trying to argue, just stating the facts of my '68 Firebird 350 with a/c and all baffles in place. In traffic the engine runs about 180 with a/c on. But on the interstate with or w/o a/c on it will, and always has since 1978, run 220 -230 and has never had any issue or boil over. All my vintage ('68-'73) V-8 Pontiacs have done this except that the interstate temps were about 10 deg cooler than the FB.

I have tried the cast pump, clearanced, and even installed an aluminum rad last year and my results are the same. My engine just likes "high" temps period!!! And never "cooked" the automatic trans yet either.

I don't worry.

DanC

[Ed Fitzgerald]

The rad cap also plays a big part in the amount of heat the engine can withstand. The 15# rad cap changes the boiling point of the water by 45 Degrees. (1lb=3*) So that equates to 257 degrees and that may be why pontiac manuals advised you shut the engine down at 240. Ed

[FrankieT/A]

Originally Posted by DanC

Not trying to argue, just stating the facts of my '68 Firebird 350 with a/c and all baffles in place. In traffic the engine runs about 180 with a/c on. But on the interstate with or w/o a/c on it will, and always has since 1978, run 220 -230 and has never had any issue or boil over. All my vintage ('68-'73) V-8 Pontiacs have done this except that the interstate temps were about 10 deg cooler than the FB.

I have tried the cast pump, clearanced, and even installed an aluminum rad last year and my results are the same. My engine just likes "high" temps period!!! And never "cooked" the automatic trans yet either.

I don't worry.

DanC

What rear gears are you running?

[bsblguy]

My '75 TA ran 180 in traffic with ac on all day long but temp climbed when on hwy. Found my lower radiator hose collapsing at higher rpm blocking water flow. Put new hose on with spring in it and now runs at 180 all the time.