2021 Ram 3500 H.O.

ShinerBock wrote:

4x4ord wrote:
Your claim that v engines require more cooling capacity than inline engines is confusing me. I might believe that heat management in a V engine is more involved. I can see why a v engine might tend to run a little hotter (which could mean less demand on the cooling system). What exactly do you mean saying a V engine require more cooling. Are you simply meaning that the greater surface area of an inline engine can radiate a little more heat directly into the engine compartment vs a more compact v engine?

It's actually not a claim. It is the truth according the PB/KW/PACCAR engineers and is one of the reasons why engines CAT 3408 or Detroit 8V92 is no longer around in the class 7-8 trucks anymore. The cooling system requirements were greater than the comparable inline 6 engines and added more weight which is a hot commodity on a commercial truck. The other main reason was that it was a fuel hog. As far as the exact or scientific reasons why V engines tend to run hotter, I have am not 100% sure.


I would still check that cap and the system for boost leaks.

The inline has many advantages over the V configurations especially with regard to servicing and especially in something like a class 8 truck where an inframe engine rebuild is common. I think the way the inline breaths can sometimes encourage better cylinder scavenging which can contribute to a more efficient engine. The reverse flow cylinder heads of the 6.7 Powerstroke is, in part, an attempt to gain better scavenging.

"it was a fuel hog" Might have been in part due to the challenges arising from the V block configuration. A fuel hog needing more cooling makes perfect sense. If one engine vs another burns more fuel to do the same amount of work, the less efficient engine is converting less of the fuel's energy to power output and therefore a higher percentage of energy is being lost. A small amount can be lost through the exhaust as unburnt fuel (smoke) or in the form of noise and vibration but the majority of loss is in the form of heat energy lost through the exhaust (higher EGTs), or into the cooling system. I am not certain but I think the idea of a V running hotter has to do with the heat from the engine accumulating in the V which can lead to all sorts of challenges from warming the intake air and fuel to heat stressing wiring harnesses and electronics. In my way of thinking about this an engine running hotter (assuming the same efficiency) is putting less heat into the cooling system.

I think the cap on my Pete was checked but I'll have it rechecked. I can check for boost leaks as well. Thanks.