underhood temps?

[optionizerSS]

Am I imagining things or are my underhood temps really high? When we first got the car we thought maybe the heater was stuck on. As I was working on this shift kit and sticking my hand back to pull the dipstick I felt the temps were very high. Tonight hit it with my laser heat gun. Intake manifold on the top was about 180* and the rear of the passenger side valve cover was about 260*. Is this normal for SN95's? Have the 5.0 and it is all stock.
Engine temp seems normal. Gauge only up about 1/4 of the way, never past half way.

 

[RAU03MACH]

Well it has been hot
So Temps are going to rise
That about right

 

[optionizerSS]

yeah i just did a search and seems quite a few have asked the same question so must be the 'norm'.

 

[wmfateam]

As a member of the hood vent cult, perfect time to install a vent : )

 

[cobrajeff96]

Depending on where you sample temps, the closer you get to exhaust manifolds the weirder things will seem. As long as the coolant holds at or less than 230*F then all is well, 230 being the absolute upper limit.

 

[ttocs]

one thing to check is if you still have the plastic air deflector on the bottom of the core support. It helps to suck the heat out of the engine compartment when it is rolling.

 

[Michael Plummer]

A big misconception is that hood vents are to control underhood engine heat, and that's not the case. What's important is the stuff in front of the car, the heat exchangers (radiator, intercooler, tranny cooler, power steering coolers, etc.). All those coolers only work if you have air going across them. So the hood vent's purpose is to help pull air across those heat exchangers. Because it's important to remember that airflow is all about going from high pressure to low. If you don't give the air somewhere to go, you'll end up with high pressure and no airflow. That's why venting is crucial, it provides a way for the high-pressure air to escape, so your engine bay is filled with cooler, moving air.

You'll want to place hood vents in low-pressure areas on the top of the hood to promote maximum airflow and not areas where you may think looks cool. Keep in mind that when you're sitting still, you'll still be generating heat under the hood, so it's important to have a good cooling fan to help dissipate that heat. If you ram air into your engine bay, you have to give it somewhere to go, or you'll end up with high pressure and no airflow.

I would like to add that hood vents are generally more beneficial in vehicles with high-performance engines or those that generate a significant amount of heat. Some vehicles, especially sports cars or vehicles with power-adder engines, may already have factory-installed hood vents designed to optimize cooling. If not, then adding one can be beneficial.

In closing, it's important to note that hood vents alone may not solve cooling issues if your vehicle is experiencing significant overheating problems. They should be considered part of an overall cooling system, including components such as the radiator, cooling fans, and coolant. If you're experiencing persistent overheating, consulting with a professional in this area makes sense.

I hope this helps.
Michael Plummer

 

[Michael Plummer]

I almost forgot to address the importance of underhood temperatures.

1. Engine Performance: Engines operate optimally within a specific temperature range. If the underhood temperatures are too low, the engine may struggle to reach its optimal operating temperature, which can negatively affect fuel efficiency, emissions, and overall performance. On the other hand, excessively high underhood temperatures can cause overheating and lead to engine damage or failure.

2. Component Longevity: Many components in the engine compartment, such as the radiator, hoses, belts, and electrical systems, are designed to function within specific temperature limits. Excessive heat can accelerate the wear and deterioration of these components, leading to reduced lifespan and potential breakdowns. On the other hand, consistently low temperatures can affect lubrication and cause premature wear.

3. Safety: If the engine overheats, it can lead to steam or coolant leaks, which may cause scalding or burns. Additionally, extreme heat can affect the integrity of surrounding materials, potentially resulting in fire hazards.

To manage underhood temperatures effectively, vehicles are equipped with cooling systems, including radiators, fans, coolant, and heat shields. Regular maintenance, such as checking coolant levels, inspecting hoses and belts, and ensuring proper airflow, can help maintain optimal underhood temperatures and prevent overheating issues. As a rule of thumb, approx. 100 degrees over ambient temperatures is considered normal for engine bay temperatures for a "street car."

I hope this helps
Michael Plummer

 

[RAU03MACH]

One reason I prefer a cowl hood with the vents o

 

[cobrajeff96]

Cowl hoods will actually hot help that much. When the air rolls over the top of the hood, it curls back inward and pushes air into the engine bay, defeating the purpose. Cowls are usually installed because of clearance issues.

 

[Monsterbishi]

At the end of the day, our engines are just a massive lump of heat retaining cast iron, the only way to manage that is to let air in from the high pressure zones (front/hood) and let it out via the low pressure zones (sides/underside)

Ceramic coating the exhaust headers/h-pipe is a good first step if it's a battle you want to fight.

 

[duh09]

At the end of the day, our engines are just a massive lump of heat retaining cast iron, the only way to manage that is to let air in from the high pressure zones (front/hood) and let it out via the low pressure zones (sides/underside)

Ceramic coating the exhaust headers/h-pipe is a good first step if it's a battle you want to fight.

Well these cars feed mostly from the bottom, but your mind is in the right space.

 

[RAU03MACH]

Cowl hoods will actually hot help that much. When the air rolls over the top of the hood, it curls back inward and pushes air into the engine bay, defeating the purpose. Cowls are usually installed because of clearance issues.

your cowl has vents in the rear or not
mine dose and you can feel the fan pushing the hot air out through the back cut outs
so i know if your moving forward the air goes through the front grill pushing hot air out the back cut outs

 

[cobrajeff96]

I don't use a cowl hood.

When sitting still or going very slow in traffic, yes, there is no air moving around the vehicle so you will notice that hot air will exhaust out of the cowl. But when the car is moving at freeway speed, the opposite will happen. It's just aerodynamic principle.

 

[RAU03MACH]

mine seems to run pretty good its not overheated or anything
once that fan kicks on i can feel the hot air out the back of that hood