normal operating temp

[daveid]

whats the normal operating temp on a high performance 454?

[public]

160-195 depending on the thermostat you put in. Emission Control systems usually require 195.

[MagicRat]

public is correct. The 'stat determines operating temp. However, the temp at the temp sender may be a bit different than at the 'stat. 160 to 220 deg operating temp is normal.

Generally, cooler is better for performance, since it heats up the intake charge less and keeps it more dense for more power.
However, engines wear out slower, oil lubricates better combustion is more efficient and complete, at slightly higher temps.

IMHO use a 180 stat for a non-electronic fuel system, like a carburetor.
Most EFI and electronically controlled carb systems need a 195 'stat to work properly.

[public]

I have a 185 degree in my 94 cavi after several years without one. Without the thermostat it ran barely over 120 Even at very these low temps I had no performance issues. I suppose MPG was lower but I did not notice it.

[MagicRat]

Originally Posted by public

I have a 185 degree in my 94 cavi after several years without one. Without the thermostat it ran barely over 120 Even at very these low temps I had no performance issues. I suppose MPG was lower but I did not notice it.

Theoretically the coolant sensor would read low and make the ECM run the engine a bit richer.
Also, cooler engines DO wear out faster, according to International Harvester's research, published an an high school textbook I have.

However, I have an '88 Bonneville with a 3800 V6. Many of those engines had a defective thermostat housing that prevented the car from warming up properly for the cooler half of the year. GM had a technical bulliten on them and provided an upgraded part, although I never changed mine. I never noticed a mileage difference either.

[daveid]

thanx guys

[curtis73]

Yup, listen to these guys. Engines like to run hot, drivers like them to run cool.

Some interesting research can be found at evanscooling.com about the breakdowns of engine parts at certain temps. Evans makes a non-aqueous Propylene Glycol coolant that I use in a couple cars. Since its not mixed with water, it doesn't boil until something like 386 degrees. So, they did a test on some oils to see where they start breaking down. The results were interesting.

The benefits in this case were that with a certain type of synthetic oil, they found the best combo at about 280 degrees. At that temperature, MPGs were high, they could run leaner jets, and the oil's life was maximized. Of course, it took a performance hit, but for most car owners they'd be glad to give up 5 hp for an extra 100k of engine life. Heat transfer was still excellent since there was no boiling taking place, so detonation wasn't an issue.

Neat stuff over there at Evanscooling.com

[public]

Originally Posted by curtis73

Yup, listen to these guys. Engines like to run hot, drivers like them to run cool.


Neat stuff over there at Evanscooling.com

Thanks, I'll check them out later. What is the cost for the coolant you mention? Here in Florida that high boiling point could be real handy.

[MagicRat]

Originally Posted by public

I have a 185 degree in my 94 cavi after several years without one. Without the thermostat it ran barely over 120 Even at very these low temps I had no performance issues. I suppose MPG was lower but I did not notice it.

Of course, you live in Florida so you can get away with it.
Try that here in Ontario in mid January, at about minus 20.
With no engine temp and no heat, your feet will freeze to the pedals!!
Last winter I had to wrap my Bonneville radiator in cardboard so it would warm up!!

[curtis73]

Originally Posted by public

Thanks, I'll check them out later. What is the cost for the coolant you mention? Here in Florida that high boiling point could be real handy.

I forget exactly, but NOT cheap. Over $100 for a full fill up I think.

[CBFryman]

$100 for a full fil up. i'd have to have a damn hot engine to run that stuff.

[curtis73]

No kidding. I run it because its invaluable for extreme duty. The problem with mixed coolant is that where the coolant contacts the chambers, nucleate boiling takes away a good bit of the surface area for heat transfer. At that point, heat isn't transferring out of the chamber and detonation starts happening. The detonation is happening because heat isn't leaving fast enough, not because of the temperature of the coolant.

With the Evans coolant, there is no nucleate boiling and heat transfer stays constant. I've had my Caddy 500 up to about 265* and have nary heard a ping. Its a tow mule, and its nice to know when I'm climbing the mountain to Flagstaff with my foot to the floor (making 450hp and towing 10,000 lbs with the timing at 36* BTDC with 9:1 compression) and the needle starts creeping up past 240, I can just keep my foot in it. I can hear my oil basking in its glory, and I can feel the sludge getting melted out of the nooks and crannies of the engine.

Its not worth it to run it in a plain old car. If a car overheats in daily commuter traffic, something is wrong with it that shouldn't be crutched with expensive coolant. But for diesels, tow mules, and other extreme duty vehicles it sure is nice. Another nice thing about this stuff is that I had this Caddy 500 in storage for four years. When I drained the Evans coolant out to remove the engine, the inside of the water passages looked like a fresh casting. No water, no air means no rust.

[CBFryman]

but what a pain if you are planing a mod that requires coolant drainage. and most any medium to major modification require coolant drainage. id be saving what i could. lol. i wonder if anyone has use a liquid metal as a coolant. such as mercury. that would be expensive and dangerous but it would probably keep the engine very cool.

[curtis73]

I've drained the coolant a few times and was able to retain almost 100%. I keep a spare gallon around and I've not had to use more than about a half of it.

Another nice thing about it is it doesn't need a pressurized cap. I keep a 1 lb cap on mine just to prevent that "sweet" smell but since there's no water to boil, it doesn't need any pressure. You'll never "blow" a hose, but if you develop a leak chances are you'll notice it before it leaks more than about a cup.

[daveid]

well what about an application with aluminum heads? shouldnt it run a little cooler or not?