[Firebob]

I'm sure this has been debated to death but let's hear some opinions on the right temp a well built Pontiac motor should operate at?
You hear people talk about temps of new cars but that's not where most of us are at. I thought most of these cars came from the factory with 190 thermostats so I'd guess that would be the minimum. I'm guessing around 200 would be the norm but what about higher? Certainly not over 240.

[Sirrotica]

Originally Posted by Firebob

I'm sure this has been debated to death but let's hear some opinions on the right temp a well built Pontiac motor should operate at?
You hear people talk about temps of new cars but that's not where most of us are at. I thought most of these cars came from the factory with 190 thermostats so I'd guess that would be the minimum. I'm guessing around 200 would be the norm but what about higher? Certainly not over 240.

At 240, under racing conditions, you stand a good chance of having a lot of scrap metal to put in a container to take to the recycling center. I found out the hard way.

Upon rebuilding the engine with 8 new pistons, rings, new bearings, and removing all the aluminum and bearing material from the oil galleys I redesigned the cooling system to run at 180 under extreme conditions, and ran that race car for 2 1/2 years without issue.

Just to be clear this was the oval track GP in my third picture, not a street car.

[PDC]

Back in the days when Nunzi and H.O. Racing were the only game in town, the generally accepted rule of thumb was that cooler was better and everyone was running 160* T-Stats. Of course, much of the equation depends on the climate where you live and drive.

My Red car over-heated, vapor-locked and stalled out one very warm night when it was still pretty new to me. I put in a new factory style brass/copper 4-core radiator, a Flow-Kooler H2O pump and a 160* stat and she has run nice and cool ever since - even on really warm days.

[RocktimusPryme]

I see people all the time talking about getting their car to run 180 or less in the heat with the AC on. I’m not sure how necessary that is. The piece of mind is nice though.

My LS2 C6 regularly ran 200+ degrees as designed. Up to like 225 on hot desert days climbing an incline. How much of that is modern more efficient design idk. Is it just as safe to run a cast iron Pontiac at those temperatures?

[track73]

The Technical books I have read on auto mechanics say that engine wear increases if the coolant temp is below 180. The engine has to get hot enough to evaporate the water that is a byproduct of combustion and let the engine metals expand to their proper size. Anything over 230 would make me worry. Oil temps are usually 20 to 30 degrees hotter and you don't want the oil to get over 270.

[steve25]

Cooler air Intake temps are the best way go and in regards to power levels at cruse rpms a 160 degree stat can help , buy not by all that much, maybe 5 hp.

All bets are off at full throttle due to the fact that after 4 seconds of peak load unthermal coated Intake valves are already glowing a dull red due to the cylinder temps seen, so even a 120 degree T stat is not going to make a Snow balls in Hell difference in power!!

[JLMounce]

I believe you have a Sniper or FiTech on the car correct? Assuming you run on the t-stat, you can't really run a 160. The throttle body EFI systems on the market don't learning and adjusting past it's factory VE tables until 150 degrees. So you want to be above that.

My KRE headed 455 likes a little heat in it. As long as it's not sucking a bunch of hot air, there's a noticeable difference in power and responsiveness between 170 degrees of water temp and 190.

[george kujanski]

My opinion is to use a thermostat at 180 0r 190 and the engine should run at that all day. If the engine temp goes much above that at some running condition, such as long idling, the temp should back down quickly once the running condition changes.

Temps rising above tstat values at higher speeds where there should be sufficient air and coolant flow indicates something is amiss.

My opinion...of course, I'm not in Arizona either, so I don't have a baseline for that.

George

[72projectbird]

On the Pontiac powered stuff, I like it below 190, preferably 180 and below.

On the LS powered stuff, they seem to run right at 200.

[Tom Vaught]

Originally Posted by track73

The Technical books I have read on auto mechanics say that engine wear increases if the coolant temp is below 180. The engine has to get hot enough to evaporate the water that is a byproduct of combustion and let the engine metals expand to their proper size. Anything over 230 would make me worry. Oil temps are usually 20 to 30 degrees hotter and you don't want the oil to get over 270.

We have a lot of data on Police Vehicles and equip them with oil coolers for a reason.

Our data showed that conventional oil would break down over 240 degrees F (Oil temp).
This means that if you are assuming 30 degrees higher oil temps as being ok, you are really taking a chance with the oil protection.

We have used Laminova oil coolers because they can easily be added to Police Vehicles (and other vehicles). This is not an advertisement, this is passing on valid info

I have posted on this before on PY.

In Picture #1 you can see the Laminova "Insert Piece" It has massive amounts of fin area to cool the oil.

In Picture #2 you see the Oil Flow and Water Flow for the units

In picture 3 you see the typical unit that we used for our vehicles.

In Picture 4 you see how the water comes in the blue section and the oil travels around the fins in the red arrow areas

In Picture 5 you see they offer different sizes of units. I have used a small one to cool the Oil Temp feeding the Turbo CHRA.



Tom V.

[Steve C.]

Tom, with or without a thermostat ?

Here Canton’s thermostat is discussed:

https://www.streetmusclemag.com/tech...-you-need-one/


.

[george kujanski]

So Tom, you transfer the excess heat from the oil into the engine coolant similar to what is done with auto trans oil.

I like to use synthetic oil because it's claimed to take higher temps and of course, winter starting ease...1 oil fits all for me.

A while back, my son did some road racing in his 2000 TA WS6, and they (OEM) use a "cooler' for the steering oil in the upper radiator hose......oil was foaming out the filler at the end of the race. Later the cooler leaked and was replaced with a oil-to-air unit
.
George

[JLMounce]

I’ve never seen those oil coolers before, but that’s got my interest piqued!

I would think because that coiling device is tied to the cooling system, you wouldn’t need a thermostatic valve. The oil temp will regulate with the water temp.

[Tom Vaught]

Originally Posted by JLMounce

I’ve never seen those oil coolers before, but that’s got my interest piqued!

I would think because that coiling device is tied to the cooling system, you wouldn’t need a thermostatic valve. The oil temp will regulate with the water temp.

That is true.

As far as the cop cars go, the engines (when in high speed mode) have a lot of air flow passing thru the radiator. The oil cooling device functions just like a engine block does,
heat transferred from the oil in the block to the water in the block.

Except the Laminova unit is much more efficient at transferring the heat.

Again, no commercial. Just a alternate method of cooling used by a lot of Police type vehicles. You will probably never damage the Lamanova due to vibration unless you screw up the installation. The outside housing is built like a tank.

Tom V.

[Steve C.]

"The oil temp will regulate with the water temp."

Now can the issue becomes oil too cool, below 212 degrees ?

From Canton.... "To alleviate the creation of excessive moisture, the optimal operating range of engine oil is no less than 212 degrees, which is the point at which the water in the oil will evaporate."


.

[STEELCITYFIREBIRD]

So with a 180 stat and +30 degrees for oil temp. That puts you @ 210+ on oil temp ...where your checking it. I'm sure everyone's water temp creeps up to 190 as stat cycles/load conditions.
Producing Adequate oil temp to evap out any water content in oil.

[Sirrotica]

The oil is going to get hotter while it's in the engine, and cooled when it contacts the cooler. Ideally you want the water vaporized while it's in the crankcase so it can outgas and be vented into the atmosphere or siphoned off with PCV vacuum, or a vacuum pump. The water droplets in the cooler aren't going anywhere at all until it's back in the engine no matter how hot it is.

My 6.5 diesel has a factory air cooled oil cooler in front of the radiator so my guess is the engineers from GM/Detroit Diesel had no concern about the oil being too cold to let water separate from the oil. We're only talking about drops of water anyway, not cups or quarts evaporating. I have no worries that the heat transfer to ambient air temp is going to be too cold to trap water in the oil of my diesel. The main thing is you want the oil hot at the point in the system where it can separate, while it's contained in a vessel under pressure isn't where it will separate.

GM has used both water and air heat rejection for their oil coolers, I guess it's not clear which has an advantage.

[Tom Vaught]

Little story about air cooling using an air to air inter-cooler unit.

So some of my associates decided to put an air to air inter-cooler on a 1984 SVO Mustang years ago, I say associates because I had nothing to do with the program.

But I did have a bunch of calls later with people trying to fix some issues with it.

The 1984 SVO Mustang was sold as a car you could actually race. And there were a couple of Road Race Tracks in Michigan. http://www.grattanracewaypark.com/

So the boys put a small Air to Air Inter-cooler between the Turbo and the Intake Manifold.
They even had a little Air Scoop to let more air into the intercooler. The scoop was actually about twice the area of the 65 and 66 GTO Ram Air Scoop.

So a couple of people bought the cars and put them on the Gratten Race Track. It is a ROAD RACE TRACK

I was a SCCA Scruitineer in Michigan at the time. (fancy name for a Tech Inspector Guy).

So the guys are racing and the 1st lap the SVO Mustang Boys are leading the pack.
The second lap the guys are in the middle of the pack.
The third lap the guys are the two last place cars on the course.

This "pain" went on for the next 15 minutes of the 20 minute Session". "Caboose Guys for the Train"

So the SVO Mustang guys were not happy. So I had a little talk with them in the pit and then next race they were back in 1st plate and 2nd plate and stayed there the whole 20 minute session.

Same deal for the rest of the races until someone complained.
"THE CARS WERE NOT STOCK" THEY CRIED. They needed to have the little wimpy factory air to air inter-cooler on the cars vs the LARGE Air to Air inter-cooler that the guys had installed in front of the radiator based on my suggestion.

So just like this Radiator Thread, you put the wrong parts on the system and you will not be happy. Sometimes even if the "factory" installed them on the vehicle.

The SVO Boys just wanted to sell "IMAGE" race cars, not Real Deal competitive race cars.

So you can fix most things unless the rules have your hands tied.

Put the right parts on the engine/vehicle vs a PSP deal, even if it was a factory install.

Tom V.

ps Charlie66 has a LARGE air to air inter-cooler on the front of his 800+ hp 4 cylinder street car. Wonder why he decided to go that path, LOL!

[Schurkey]

Originally Posted by Firebob

let's hear some opinions on the right temp a well built Pontiac motor should operate at?

At idle or cruise, within a few degrees of thermostat rating.

More than 15--20 degrees hotter than the thermostat rating, and the thermostat has lost control of engine temp. This is fine for heavy-throttle bursts, but inadequate at idle or cruise with a water-pump-driven fan. (clutch or flex)

Electric-fan applications will vary based on the turn-on, turn-off temperatures.

[RocktimusPryme]

Originally Posted by Schurkey

At idle or cruise, within a few degrees of thermostat rating.

More than 15--20 degrees hotter than the thermostat rating, and the thermostat has lost control of engine temp. This is fine for heavy-throttle bursts, but inadequate at idle or cruise with a water-pump-driven fan. (clutch or flex)

Electric-fan applications will vary based on the turn-on, turn-off temperatures.

There is actually a debate on my FE Facebook group along those similar lines with the thermostat rating. The basic point was about poor choice of parts. People trying to just pop in a 160 thermostat to reduce coolant temps.

Basically, if your cooling system at 60 mph wants to run at 205* a 160 thermostat is going to be always open and pointless. But if you were to run a 195* thermostat you have a better chance of staying at your thermostat rating. When in operation it should slow down flow through the radiator allowing more heat to be pulled out.

I hve no idea how accurate it is without testing it myself, but the basic concept makes sense.