KAD300 - advice on supercharger rebuilds

Nah ... it really sounds odd / AI generated .

Aftercooling basicly has the aim to increase the total air mass available for combustion since colder air is more dense and more fuel can be burned for a bigger bang at every power stroke . A bigger bang will at the end of the day generate also more total heat .

The idea of an aftercooler cooling the piston crown by reducing intake temps similar to blow with your mouth on the spoon with hot soup sounds funny . Whatkind of cooling effect should an intake air reduction of ~30-40 deg c have when a split second later nevertheless combustion temperatures of +2000deg c will occour ?

Yes , there is evaporation cooling by injecting excess fuel or water injection into the intake of some petrol ( aero ) engines but that another story .

Not saying i,m sure but I bet that a highly boosted , aftercooled kad44/kad300 running wide open has a way higher total heat load to the coolant than its 3.6l 6 cyl 100 or so horses ancestor .
 
BruceK said:
Asking the question a different way will yield this

"
Yes, a
charge air cooler (intercooler) and forced induction system (turbocharger/supercharger) indirectly play a significant role in cooling the piston, cylinder, and combustion chamber in a diesel engine.
While the primary, direct cooling of the piston and cylinder is handled by engine oil (via piston cooling jets) and liquid coolant, the charge air cooler ensures the intake charge is dense and cool, which directly reduces the thermal load on these components.
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Agreed - if the turbo isnt taking over the supercharger A) supercharger is going to get hotter and overworked Hence the OP mentioning the colour of his oil (Probably cooked) and B the Flow of coolant and raw water going around the engine is going to be less which increases the Engine Temps - In My Opinion
 
aerobat said:
Nah ... it really sounds odd / AI generated .

Aftercooling basicly has the aim to increase the total air mass available for combustion since colder air is more dense and more fuel can be burned for a bigger bang at every power stroke . A bigger bang will at the end of the day generate also more total heat .
Click to expand...

Nobody, but nobody disputes that. Its what happens before the ignition we are talking about. The point where cooled pressurized gas suddenly enters the combustion chamber, expanding and thus cooling even further. That point right there, before the compression stroke, cools the chamber down from its exhaust stroke. Yes then you get a nice big bang with more fuel but because you started the compression stroke at lowered temps the combustion chamber does not get as hot. Remember. diesel ignites because of compression and not heat or spark. You can ignite it nicely in a nice cool chamber just peachy.

Ag man. If you cant see it you never will. But do yourself a favor. Ask the forum why my engine overheats and I bet half the answeres will ask you to do a boost check on your turbo. Go figure. People get their heads around that bit because its empirical. They have seen it for themselves. Understanding why though well, you are a case in point. I dont post much anymore. I came in because the forum gave me an email alert that I had been called in by Pete. I dont post to be heard in the community just to provide some advice. You can believe whatever you want.
 
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aerobat said:
Not saying i,m sure but I bet that a highly boosted , aftercooled kad44/kad300 running wide open has a way higher total heat load to the coolant than its 3.6l 6 cyl 100 or so horses ancestor .
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Ya and. ........... ? Common you are almost there. ........ and this massive heat load doesnt turn the engine into a melted mass because.... you're so close, one more step
 
A design point of interest in this "debate" is the KAD44 and 300 changed the raw water cooling route. In earlier generations the priority was oil cooler, then coolant heat exchanger and finally charge air cooler. They changed the priority to charge air cooler to get the coldest water first on these models. Ever wonder why?
 
BruceK said:
A design point of interest in this "debate" is the KAD44 and 300 changed the raw water cooling route. In earlier generations the priority was oil cooler, then coolant heat exchanger and finally charge air cooler. They changed the priority to charge air cooler to get the coldest water first on these models. Ever wonder why?
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Money saving….less pipework 🤣🤣
 
BruceK said:
A design point of interest in this "debate" is the KAD44 and 300 changed the raw water cooling route. In earlier generations the priority was oil cooler, then coolant heat exchanger and finally charge air cooler. They changed the priority to charge air cooler to get the coldest water first on these models. Ever wonder why?
Click to expand...

To maximize the performance of the charge air cooler and so to beat every horse out of the block they only can .

Bruce , i on no case want to argue here and i highly respect your knowledge but i still never heared that the charge air cooler has something in common with actually cooling the engine . As well i never heared a weak turbo alone will cause engine overheating .

On a kad300 the ECU will just reduce fuel delivery since it has a mapping of fuel vs rpm vs boost pressure . You will see low output and in a KAD application the compressor cycling in and out .

What i am missing ?
 
aerobat said:
To maximize the performance of the charge air cooler and so to beat every horse out of the block they only can .

Bruce , i on no case want to argue here and i highly respect your knowledge but i still never heared that the charge air cooler has something in common with actually cooling the engine . As well i never heared a weak turbo alone will cause engine overheating .

On a kad300 the ECU will just reduce fuel delivery since it has a mapping of fuel vs rpm vs boost pressure . You will see low output and in a KAD application the compressor cycling in and out .

What i am missing ?
Click to expand...
There are many failsafes in the later engines 44 and up with engine management. The earlier versions are restricted by smoke limiter. Note in your own words the compressor cycling in and out. Think about it. Why would you want a compressor to cycle in and out if your ecu can just reduce fuel to compensate? On a 42 and 43 the answer is the simple in that it has no ecu and so its a simple rev match criteria but in a 44 and 300? I get you are struggling with this so lets just drop it. You can chose to ignore this or do your own research now.

no matter how you ask the question the answer is always the same

Yes, forced air induction can help cool the piston and combustion chamber
, but this effect is complex and often accompanied by higher overall engine temperatures. The cooling effect is primarily achieved through the increased volume of cooler, intake air-fuel mixture that passes through the chamber during the intake stroke.
Here is a breakdown of how it affects cooling:
1. Cooling Mechanisms of Forced Induction
  • Intake Charge Cooling: Forced induction (turbo/supercharging) introduces a larger mass of cooler air-fuel mixture into the combustion chamber. As this charge enters, it absorbs heat from the hot cylinder head, valves, and piston head before ignition, providing an immediate cooling effect.
  • Intake Air-Fuel Charge Density: The intake charge cools the chamber walls, including the cylinder walls and the top of the piston.
  • Intercooling (Charge Air Cooler): Because compressing air creates heat, forced induction systems use intercoolers to lower the temperature of the air entering the engine, which helps prevent premature detonation (engine knock) and reduces heat stress on components.
2. Factors That Counteract the Cooling
  • Increased Combustion Heat: While the intake charge brings in "cool" air, forced induction is designed to burn more fuel to make more power. This results in significantly higher peak combustion temperatures.
  • Heat from Compression: The process of compressing air raises its temperature, which can lead to higher cylinder head and piston temperatures if not properly managed with an intercooler.
  • Thermal Load: Forced induction can lead to higher overall thermal stress on engine parts.
3. Specific Cooling Measures Required
  • Piston Cooling Jets: To manage the increased heat in forced induction engines, specialized oil spray jets are often used to spray oil onto the underside of the piston, which acts as a crucial cooling mechanism.
  • Rich Mixture: Operating a slightly richer air-fuel mixture can also help lower combustion temperatures.
Summary
While the intake charge helps cool the chamber and piston, forced induction generally increases the engine's total heat output. Therefore, the cooling "benefit" is actually a heat management technique required to keep the engine from overheating due to the higher power output, rather than a method that reduces the overall running temperature compared to a lower-power engine.
 
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BruceK said:
[*]Rich Mixture: Operating a slightly richer air-fuel mixture can also help lower combustion temperatures.
[/LIST]
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that an interesting idea on a diesel engine . When you paste chat gpt here , ask the AI if a diesel engine by priciple has a mixture ratio at all ... ;-)

I see you are putting a lot of emotions here . Calm down , take a cup of tea and blow on the spoon .

But i like and appreciate your posts and knowledge !
 
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