Om603 Solving temp swings - PeachParts Mercedes-Benz Forum

martureo · #1 07-25-2019, 02:52 PM

Quote:

Originally Posted by JonW124

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Also the smaller Chevy thermostat works great cooling 500 plus cubic inch Chevy engines. It maybe smaller than the Mercedes T-stat but I think it can handle a 3.0 liter engine producing 150 hp.

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I don't think is this an apples to apples comparison. Diesel engines produce more internal heat energy than gasoline engines, on that alone I'd think that that the cooling systems on a diesel would be greater than that of a comparable gasoline engine.

JonW124 · #2 07-26-2019, 12:01 AM

Quote:

Originally Posted by martureo

I don't think is this an apples to apples comparison. Diesel engines produce more internal heat energy than gasoline engines, on that alone I'd think that that the cooling systems on a diesel would be greater than that of a comparable gasoline engine.

I owned a 540 cubic chevy engine that used the same thermostat I'm using in my Om603 now. My 540 BBC made 685 hp to the wheels and creates a ton of heat. I understand diesel engines create a lot of heat and the turbo really adds to that. But I drag raced that engine and drove it hard and that small thermostat had no issues. The point I was trying to make about the Thermostat size is that it doesn't matter if the cooling system is efficient.

martureo · #3 07-26-2019, 01:13 PM

Quote:

Originally Posted by JonW124

I owned a 540 cubic chevy engine that used the same thermostat I'm using in my Om603 now. My 540 BBC made 685 hp to the wheels and creates a ton of heat. I understand diesel engines create a lot of heat and the turbo really adds to that. But I drag raced that engine and drove it hard and that small thermostat had no issues. The point I was trying to make about the Thermostat size is that it doesn't matter if the cooling system is efficient.

What you're saying is that a higher flow restriction is not a problem, but that's not a true statement. We could get into the diameter of the hoses, the pump size, the flow rate of the coolant, etc. The size of the thermostat DOES matter when you're keeping everything else the same outside of the size of the thermostat.

You cannot compare a V8 gas engine to a 3L diesel just by saying "same same," nor can you compare a daily driver with a car designed to drag race.

JonW124 · #4 07-26-2019, 01:42 PM

Quote:

Originally Posted by martureo

What you're saying is that a higher flow restriction is not a problem, but that's not a true statement. We could get into the diameter of the hoses, the pump size, the flow rate of the coolant, etc. The size of the thermostat DOES matter when you're keeping everything else the same outside of the size of the thermostat.

You cannot compare a V8 gas engine to a 3L diesel just by saying "same same," nor can you compare a daily driver with a car designed to drag race.

I guess I'm not be clear. I didn't say both engines were the same. My point was that they both create a lot of heat even thought they are different. The size of the Mercedes thermostat really doesn't matter because it doesn't open enough where its located because it gets hit with cold water and closes. The chevy thermostat gets hit with a more consistent water temp so it doesn't open and close as much. If they made an inline Thermostat that used the bigger Mercedes T-Stat then I would have used that. The location of the T-Stat makes more of a difference than the size.