Optimal engine temperature for max HP?

[Edelbrock]

So lately there have been some posts about engine temps.

I wonder what the optimal temp would be for max power on a Chevy 350 or 400.

Fuel mileage and emissions are not a factor in this, just pure HP


Any ideas?

 

[xm20k]

Coolant temp plays a very small part in performance air charge temp and cylinder temp are more important.

This is why intercoolers are a thing on forced induction.
As is water meth injection.
As well as scoops and external ducting for Na engines.

 

[PrairieDrifter]

A better question, that I've never seen answered, is what is the best ambient temp? Plus factors like elevation and humidity and barometrics.

We all know colder temps make more power, but how cold? What's the point where it starts hurting performance? 32F? 40F?

I always wanted engine masters to test this, but that's not really a dyno possible activity unless there's some multi billion dollar military testing dyno that can simulate elevation and atmosphere changes.

Something I've thought about on and off for the last like 15 years lol. Never really looked into it though.

 

[Edelbrock]

A better question, that I've never seen answered, is what is the best ambient temp? Plus factors like elevation and humidity and barometrics.

We all know colder temps make more power, but how cold? What's the point where it starts hurting performance? 32F? 40F?

I always wanted engine masters to test this, but that's not really a dyno possible activity unless there's some multi billion dollar military testing dyno that can simulate elevation and atmosphere changes.

Something I've thought about on and off for the last like 15 years lol. Never really looked into it though.

I wonder if you could make a cold air intake that incorporates liquid nitrogen in some fashion. For example, if the liquid nitrogen circulated through a small radiator that covered the intake for the engine, super cooling the air that going into the engine. This would not be sustainable of course, but for a a drag race it might work. Or maybe using dry ice in some way. Would getting the air intake temps down to zero help much with power?

 

[xm20k]

We all know colder temps make more power, but how cold? What's the point where it starts hurting performance? 32F? 40F?

I think at a point it just doesn't do anything to improve performance, the engine even where force induction is concerned just can't pack in more air, but other stuff may become an issue, like things getting brittle from the low temps, fluids starting to freeze or thickening up etc.

 

[xm20k]

Would getting the air intake temps down to zero help much with power?

Latent heat of vaporization as air and fuel are drawn into an intake manifold can drop the temps in the manifold to just over the freezing point in a perfect scenario, but in a vehicle under a hood in the real world you can only do so much before cost, space, and weight become issues.

 

[75gmck25]

Don't get engine temp confused with air temp into the intake. You want air temps as low as possible to get a denser "charge" of fuel and air, but modern engines perform and last better when they run in the 200 to about 230 degree temperature range.

However, most folks don't go any higher than a 195 degree thermostat on a street vehicle, since that gives you a little more flex before you hit the 230+ range and things overheat. Using no thermostat or a 160 degree thermostat will also work fine, but on a street engine it may not be hot enough to burn off crankcase moisture, which then leads to other problems. You don't want the engine temp to run too cool.

 

[SquareRoot]

Here we go again.

 

[Keith Seymore]

My Chevelle race engine made peak power on the dyno at 164 deg coolant temp.

I can't hit that consistently after the car has been driven so I try to start my burnout at 180 deg coolant temp every time, and then monitor throughout the run.

I'm giving away some power but consistency is key.

You must be registered for see images attach

You must be registered for see images attach

 

[Keith Seymore]

A better question, that I've never seen answered, is what is the best ambient temp? Plus factors like elevation and humidity and barometrics.

We all know colder temps make more power, but how cold? What's the point where it starts hurting performance? 32F? 40F?

I always wanted engine masters to test this, but that's not really a dyno possible activity unless there's some multi billion dollar military testing dyno that can simulate elevation and atmosphere changes.

Something I've thought about on and off for the last like 15 years lol. Never really looked into it though.

Mid 60 deg F. General Motors has climate controlled cells, as you might expect.

Data is corrected back to "Standard", which is 59 deg at sea level.

Monitoring just ambient air temp, or humidty, or baro doesn't cut it. Plus - air density alone is super clunky to work with.

The thing I care about the most is "relative altitude", which is the amalgamation of air temperature, density and humidity. It is described in "feet", so one might say "Today we are at 3000 feet above sea level" - or - "today we are at -500 feet".

Right now my local track is 68 deg F, 68% humidity and 30.04 barometric pressure for a relative altitude of 1752 ft. Standard correction factor is 1.0451.

I want that to be as close to sea level as possible, for max power. Below sea level is somewhat unattainable but wonderful when you can get it.

Most of my events through the summer are 1000-3000 feet. I wait until the fall to try to break my personal best records and have seen below sea level at that time of year.

St Louis is a nice venue for that. I have been to the track when the air is so dense it draws attention to itself. You could feel the air on your arms.


K

You must be registered for see images attach

You must be registered for see images attach