Official Cummins 6cta 450C thread

I am right behind you Jay. Pulled mine this morning for the bi-annual cleaning. I see you also have one of the new ultra expensive versions with the air side drain plug. My gear oil coolers are brand new so they aren't coming off. And I removed and pressure tested the heat exchangers two years ago. So this year I'll leave them installed and just remove the end caps and rod out the tubes.
 

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Two year old new style pulled right apart. Zero pitting of any kind. All the black interior coating still on it. Looks brand new. Maybe this new design has some merit. The other one which is old style - haven't managed to hammer out the core yet. Being stubborn.
 

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Got the old style one apart. Just took a bigger sledge hammer and some back and forth sliding to get the corrosion to fall off. Housing looks good. Same as it was when I put it together two years ago. You can see a collection of corrosion on the top of the core, which is actually the bottom as I have it turned upside down. This one is about 6 years old. Going to clean it up and put it back together and go for two more years.
 

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Bill, you have a keen eye. My Port After-cooler is brand new. It was a condition of sale 2 years ago. We disassembled the AC's Saturday. The funny things was on the Port side (brand new core and housing), only one end was greased. And they still had the "plastic strip thingies" on the four "sides" of the core, which made extraction a real PITA. The Starboard After-cooler was greased on both ends and those strips were not present. The core slid out very easy. We ended up removing the strips on the new core before reassembly. The cleaning process I think attacks that "plastic".

I removed the endcaps from the heat exchangers yesterday and rodded out the tubes with the stainless steel rod that Tony sends you in the kit. Not much of anything came out. Easy as pie. I was amazed at how little torque was on the endcap bolts. Like finger tight plus 1/4 turn.

We installed the new oil coolers the other day. The only thing we may have to "correct" is to rotate the oil cooler a bit to make room between their zinc (original coolers didn't have zincs) and the After-cooler. That will be a determination at re-install. As for the drain on the new design, yes it is there, but I've never "opened" it nor is it connected to anything. Should I? I didn't have any of the "white stuff" on the fins. Just the black film on the air inlet side. The outlet side of the core was very much copper color. I didn't take a lot of pictures because my hands were dirty/greasy. Here is one to document the orientation of the core prior to removal.

That's the drain by my finger, right?

rmclok....I tore the hose on the turb air side before it enters the after-cooler. I made the mistake of having the parts dept at the marina order it for me. They are much cheaper at sbmar like Bill said. Trust me!
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I don't have the drain like you have on the new aftercooler. I have the plugs that come in it. Brad at sbmar told me just remove the plugs once every few months and let any condensation drain out. So that's what I did. He said I could buy and add the drain like you have so that the condensation freely drains continuously, but he says the periodic plug removal method is good enough
 
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Since the port aftercooler is off it's pretty good access to the water pump. So I figured after 4 years and 700 hours I better change the impeller that came installed in the SMX pump. Holy cow, not a crack or brittle spot on it. Still looks and feels new.
 
So I figured after 4 years and 700 hours I better change the impeller that came installed in the SMX pump. Holy cow, not a crack or brittle spot on it. Still looks and feels new.
That's incredible... After 750 hours I am looking at replacing my pumps....and your just replacing a good impeller...crazy
 
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That's incredible... After 750 hours I am looking at replacing my pumps....and your just replacing a good impeller...crazy
I suggest you replace them with the SMX pump from sbmar.com

I just reported this to Seaboard Marine and they explained that just before I bought mine they switch from a Korean manufacturer to an Italian manufacturer for the impellers. And since then they are getting reports of much longer life for the impellers.
 
I suggest you replace them with the SMX pump from sbmar.com

I just reported this to Seaboard Marine and they explained that just before I bought mine they switch from a Korean manufacturer to an Italian manufacturer for the impellers. And since then they are getting reports of much longer life for the impellers.
That is my intent... I have looked at the improvements Tony has made over the OEM pump...he has definitely made a better mouse trap.... Thanks
 
View attachment 61432 Since the port aftercooler is off it's pretty good access to the water pump. So I figured after 4 years and 700 hours I better change the impeller that came installed in the SMX pump. Holy cow, not a crack or brittle spot on it. Still looks and feels new.
I'm at the 2 year mark with SMX and will push it at least another year. I'm hearing good things with SMX and with your 4 year supporting information, it just helps my decision. Good stuff, thanks
 
Hello all, in our search for the next boat we happened across a 04 420DA with 6CTA 450 engines. The boat has about 400 hrs and is in pristine condition. Speaking with the owner he said his WOT is at 3000 rpms. i didn't get too into it with him as i thought i may have misread but now that i come back and check those engines are rate for 2600rpms at WOT. We may move ahead with the boat but wondering if he's just misinformed. Seemed as if all services were up to date. Seller seemed very open about his maintenance however didn't strike me as someone who paid too much attention to specs.
 
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I'll bet he is referring to the max RPM in neutral. IF they do reach 3000RPMs under load then the props are way undersized.

Josh
 
Hello all, in our search for the next boat we happened across a 04 420DA with 6CTA 450 engines. The boat has about 400 hrs and is in pristine condition. Speaking with the owner he said his WOT is at 3000 rpms. i didn't get too into it with him as i thought i may have misread but now that i come back and check those engines are rate for 2600rpms at WOT. We may move ahead with the boat but wondering if he's just misinformed. Seemed as if all services were up to date. Seller seemed very open about his maintenance however didn't strike me as someone who paid too much attention to specs.


Sea trial the boat....you need to hit 2600 MINIMUM. Ideally, 2700 is the number to avoid overloading in rough and heavy gear conditions.
 
How long does a coolant filter last if you don't need to replace it? I put the blank WF 2077 on last fall and I just tested the coolant and I am still well in the green. Can I leave the blank on for another year or should I replace with a new blank?

Is the filter there only as a way to add SCA? Or does it actually filter something?
 
How long does a coolant filter last if you don't need to replace it? I put the blank WF 2077 on last fall and I just tested the coolant and I am still well in the green. Can I leave the blank on for another year or should I replace with a new blank?

Is the filter there only as a way to add SCA? Or does it actually filter something?

It actually filters the coolant.
Every oil change is the trigger to test the coolant and change the filter. If good, replace with 2 or 4 unit filter. If on the higher side of the range, replace with the blank.
More dca’s is not better, stay in the range.
 
Got the old style one apart. Just took a bigger sledge hammer and some back and forth sliding to get the corrosion to fall off. Housing looks good. Same as it was when I put it together two years ago. You can see a collection of corrosion on the top of the core, which is actually the bottom as I have it turned upside down. This one is about 6 years old. Going to clean it up and put it back together and go for two more years.
Hi Bill,

I'm not a Cummins guy, but I am a member of Tony's BoatDiesel.com and I recall, when I was considering a 52 with QSMs, reading an article about reassembling the HE's with a generous amount of "Jet Lube" to help prevent that corrosion. I may be wrong on this as it was 3 years ago, but tony had a good article on the HE's disassembly and and cleaning...
 

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