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Are Marine Blocks And Heads The Same As Automotive?

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I read that cummins put out a QSB 5. 9 425h. p. and was wondering the differences between it and the 325h. p. automotive engine. I wonder if the injectors are different and if they would fit. Does anyone one know what the compression ratio is on that paticular engine?
 
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Yes their is a differance but you have to know if your marine engen has a direct or indirect cooling systems. I have a indirect on my guide boat and I can run it in the salt water without salt water in the engin the intake puts water in a seeled system and thin it goes out the exaults were the direct systems puts water for cooling the engine in direct contact with your engine parts and that is were the two are differant marine engins are treated so that they have more resistants to the water corroding activities that goes on inside. Many people try to save a few bucks by buying regular auto parts for their marine engines. hope this helps hjc.
 
doesn't the QSB use the rear mounted cam drive? otherwise the heads and such might be the same. I have no idea about the injectors but I would bet the difference between the two is just computer programming.
 
The head and engine blocks are the same from marine and automotive engines. Diesel marine engines use water jacketed exhaust manifolds, turbos and water cooled intercoolers. In most diesel marine engines the water is picked up from outside of the boat, this is known as raw water, passes throught a water pump, than passes through the intercooler. After the intercooler the raw water pass through the jacket water cooler. The jacket water cooler is a shell tube design where raw water fills the tubes and jacket water feels the outside of the tubes. The jacket water cools the water that cools the oil and the engine block, head exhaust manifold, and turbo. When the raw is done with the jacket water cooler the raw water in injected in to the turbo down tube and exits the boat with the exhaust. Diesel Marine engines will have a larger oil pan and heavy duty pistons that I know of.
 
I found the compression ratio for the marine engine. 17. 2 to 1 for the qsb 5. 9 380 and 16. 7 to 1 for the the 425 h. p. version.
 
BLACK PEARL,If the compression was the same between a 2005 marine and a 2005 automotive is there still other differences. If there are still differences do you know what they are?
 
I believe Scheid offers marine pistons as an upgrade to our engines. They have a ceramic coating on the top.



-Ryan
 
J. Davy said:
BLACK PEARL,If the compression was the same between a 2005 marine and a 2005 automotive is there still other differences. If there are still differences do you know what they are?

Called the local Cummins Marine dealer and he is going to dig up all the part number and internal specs on the QSB5. 9 425HP and the QSB 380HP.
 
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The main difference is that the Marine versions tend to wear green and brown, and have VERY short haircuts. They also tend to make an "OO-Rah" sound as they blow a headgasket:)
 
abdiver said:
I would imagine in a Raw water cooled engines have a SS head gasket. that is how marine gas engines are



You cannot get them raw water cooled. As far as using the same blocks and heads, I highly doubt it, the marine engines operate at constant load all the time, nothing like a truck engine. I had priced out a pair a couple years ago for a boat I had, the engines were about $19k each without gears, this was the year before they switched to the HPCR design, I can only imagine what they cost now.
 
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