Can an engine be run hotter or cooler?

n.devdath · 15th April 2010, 08:57

I am starting this topic inspired by the question mooza had posted about his Scorp vibrating lesser when cold.

The question is, is it possible to make an engine function either cooler or hotter than the manufacturer set operating range?
If so, what are the the likely modifications to be done and the benefits and drawbacks thereof?

Waiting for inputs from engine gurus on the forum like DB Sir, Spike, CPH, and others.

Mods, in case a similar thread exists, please feel free to merge/delete this thread.

CPH · 15th April 2010, 09:42

You can run them hotter as well as cooler. Some 20 years ago most engines ran cooler.

You can vary the temperature by using different thermostats or you dispose of the thermostat altogether and do the same with the waterpump and replace it by an electric pump with a controller, which allows you to set the temperature much more constant than the OE set-up.

Increasing the temperature of a late engine set-up is not good news because the cooling is not equal throughout the engine and might create problems in some spots.

Temperature can also be influenced by the chosen richness. Usually engines are overfueled at the upper rpm band to prevent overheating.

Psycho · 15th April 2010, 09:51

The temperature range that a car operates in is based on multiple parameters, that help aid in better combustion and heat regulation on an engine, the cars use a device called the thermostat to regulate the circulation of coolant through the engine based on a specific temperature range and this is driven by a wax pellet, you do get other thermostats for various temperature ranges, but I doubt so for most Indian cars. You can read more about thermostats here

As for the cold start part I think the ECU actually supplies an additional burst of diesel prior to the main injection cycle to help on cold starts and engine warm up, this reduces the overall vibrations but at the same time also tends to reduce the explosiveness of the air fuel mixture. Diesels gurus please correct me if I am wrong.

15th April 2010, 08:57	#1
n.devdath BANNED Join Date: Jun 2009 Location: Bangalore Posts: 4,287 Thanked: 2,812 Times	Can an engine be run hotter or cooler? I am starting this topic inspired by the question mooza had posted about his Scorp vibrating lesser when cold. The question is, is it possible to make an engine function either cooler or hotter than the manufacturer set operating range? If so, what are the the likely modifications to be done and the benefits and drawbacks thereof? Waiting for inputs from engine gurus on the forum like DB Sir, Spike, CPH, and others. Mods, in case a similar thread exists, please feel free to merge/delete this thread.
	() Thanks

15th April 2010, 09:42	#2
CPH BHPian Join Date: Jan 2010 Location: London Posts: 579 Thanked: 36 Times	You can run them hotter as well as cooler. Some 20 years ago most engines ran cooler. You can vary the temperature by using different thermostats or you dispose of the thermostat altogether and do the same with the waterpump and replace it by an electric pump with a controller, which allows you to set the temperature much more constant than the OE set-up. Increasing the temperature of a late engine set-up is not good news because the cooling is not equal throughout the engine and might create problems in some spots. Temperature can also be influenced by the chosen richness. Usually engines are overfueled at the upper rpm band to prevent overheating.
	() Thanks

15th April 2010, 09:51	#3
Psycho Senior - BHPian Join Date: Jul 2004 Location: Bangalore Posts: 1,043 Thanked: 111 Times View My Garage	The temperature range that a car operates in is based on multiple parameters, that help aid in better combustion and heat regulation on an engine, the cars use a device called the thermostat to regulate the circulation of coolant through the engine based on a specific temperature range and this is driven by a wax pellet, you do get other thermostats for various temperature ranges, but I doubt so for most Indian cars. You can read more about thermostats here As for the cold start part I think the ECU actually supplies an additional burst of diesel prior to the main injection cycle to help on cold starts and engine warm up, this reduces the overall vibrations but at the same time also tends to reduce the explosiveness of the air fuel mixture. Diesels gurus please correct me if I am wrong.
	() Thanks