Official Cummins 6cta 450C thread

Holes are about the same size. Old holes are 9/32 and new holes are 8/32. Although the holes along the perimeter may be a bit larger. Old shower has 30 holes. New shower has 20 holes. Not sure why. I'll check with them on Monday. I looked at Fernando's pictures and they put 24 holes in his. Looks like it would be very straightforward to drill holes larger or drill 10 more holes if needed. I'll see what they say.

Other than that, the size, shape and orientation of the new mixer is a perfect match for the original.
I talked to Deangelo this morning. They said the size and number of the diffuser holes is based on the engine GPM the pump provides.
The elbow needs to stay full or it will have hot spots.
 
I talked to Deangelo this morning. They said the size and number of the diffuser holes is based on the engine GPM the pump provides.
The elbow needs to stay full or it will have hot spots.

Yep, that’s why I asked.
As you know, I do a lot of cruising at 1100-1150ish rpm, the top of the exhaust hose gets really hot at that speed ( remember those burned up hose insides I showed you) it was one of the reasons I went with the SMX pumps but they still get hot until rpm gets up to cruising speed. Theory is at lower speed elbow doesn’t quite fill up and the top holes have no water coming out. Fix might be smaller holes or less of them or smaller holes at the bottom and larger holes at the top. That would keep sq in of opening the same so water can flow at higher speed.
Sounds like maybe you have less sq in of opening with the new ones. Does that sound right?
 
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Here’s that picture of those old hoses. Burned right at the top right at the shower head.
If I recall correctly, you had the same issue with the hoses at the shower head.
Maybe you could share some IR gun numbers at the top of your hoses at the slower speeds with the new elbows.
 
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Yep, that’s why I asked.
As you know, I do a lot of cruising at 1100-1150ish rpm, the top of the exhaust hose gets really hot at that speed ( remember those burned up hose insides I showed you) it was one of the reasons I went with the SMX pumps but they still get hot until rpm gets up to cruising speed. Theory is at lower speed elbow doesn’t quite fill up and the top holes have no water coming out. Fix might be smaller holes or less of them or smaller holes at the bottom and larger holes at the top. That would keep sq in of opening the same so water can flow at higher speed.
Sounds like maybe you have less sq in of opening with the new ones. Does that sound right?
Yes. There is less open area. About 25-40 percent less. Old was about 1.47 square inches and new is between .98 and 1.1 square inches (hard to calculate the area of the oblong outer openings).

Yes, my port hose attached to the mixing elbow dried out badly and kinda crumbled. I put the blue high temp hose on.
 
Yes. There is less open area. About 25-40 percent less. Old was about 1.47 square inches and new is between .98 and 1.1 square inches (hard to calculate the area of the oblong outer openings).

Yes, my port hose attached to the mixing elbow dried out badly and kinda crumbled. I put the blue high temp hose on.

Ditto on the high temp hoses, If you get good even temperature readings on your hoses, let me know, I will have another reason for the new elbows. Thanks Bill
 
This is the turbo I had rebuilt two years ago. This is what I found when I replaced the mixing elbow. Quite a bit of scale/rust on the inside between the turbine blades and mixing elbow. I got to it early enough that it won't be a problem. It looks worse than it is as rust is 8 times the thickness of the metal it eats up. So probably about 1/32" of metal eaten up. The mixing elbow looked terrible. Lots of holes through the inner pipe that I could easily see by eye. It's now in the trash. This is on a 400DB with straight drives. Those of you with v-drive Sundancers may have a different mixer/riser setup.
 

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Silly new diesel owner question.

Based on the records from my boat’s previous owner, the aftercoolers and heat exchangers are due for cleaning after this season. My question is: does it matter when I do this? That is, before winterization, or do I wait until the spring commissioning?
 
Pull them when your done this season. Good winter garage project. Give them a nice paint job when their done and slap them back on in the spring.

But wouldn’t the anti freeze that I run through my engine to winterize also run through the HE? So wouldn’t I need that installed when I’m winterized?
 
I thought about that but also wondered if you were staying in or going on the hard for the winter.
My bet is that you can winterize, then pull your parts even though some antifreeze will drain out at least you won't have any water in there. I'm sure the diesel guys will set us straight. #Watching/learning
 
Steve, When you run the pink through the system it obviously flows through everything, but when you shut down the engine, it all runs out the bottom of the boat through the shaft seals except for about 1 1/2 quarts that stay in the bottom half of the aftercooler, the fuel cooler and its hoses.Take a good look at the plumbing on our motors, you will see that the shaft seals are fed from the rear bottom of the tranny cooler and you can see where that lies in relation to everything else.
Removing the A/C and servicing it over the winter is fine, remove the bottom anode first and drain the pink out before removing it so it doesn't spill out when you remove the A/C, filling your shoe :)
Now the HX is a little different. There will be no pink left in it, but is full to the brim with coolant. The cooling side of the system needs to be drained down to get those off.
I don't like leaving the coolant side empty over the winter. You may feel differently.
Suggest you can do the A/C's now and wait till spring to do the HX and then rehosing the coolant side hoses if they have not been done while the coolant is out.
If you feel you don't need to take the HX to the rad shop, you could barnaclebuster the raw water side in the spring and just remove the HX caps to verify everything is clean and no tubes are clogged.
 
Another HX option is to manually clean the seawater side. Take both end caps off and rod out each tube with a long enough rod to go the whole length of the HX. On the zinc end of it you may need/want to dab a little barnacle buster to get any zinc off caked onto the bottom of the tube bundle.

If you do it this way you don't have to mess with the coolant side of the heat exchanger. You will need to buy new end cap gaskets.
 
My starboard engine has been running well. No complaints with power, performance, anything. But I’m hearing a rattle with it and I don’t see anything external that is loose. So I’m thinking the worst ... valves. Can anyone offer a rough diagnosis from a video?


Thanks,
Steve
 
Maybe because I don’t have a decent speaker available to me right now but on my cell phone I don’t really hear anything. You said you took a good look around, how about up front in thebelt tensioner area?
Does it still do it when you drop it into gear? If it sounds like a general central ticking it could be valves. Take the oil fill cap off and listen. Louder?
Were valves ever adjusted? How many hours on engines?
Don’t fear valve adjustment, piece of cake. You’ll get it sorted out. Good luck
 
Speaking of valve adjustments....do you guys do that yourselves or do you have Cummins do it? The procedure doesn't seem hard, short of have that tool to lock the engine in TDC or 180 Deg off TDC, and a set of feeler gauges. But I lack the knowledge of what is the proper "feel" on the gauge.

Jaybeaux
 
Speaking of valve adjustments....do you guys do that yourselves or do you have Cummins do it? The procedure doesn't seem hard, short of have that tool to lock the engine in TDC or 180 Deg off TDC, and a set of feeler gauges. But I lack the knowledge of what is the proper "feel" on the gauge.

Jaybeaux
I hired mine out. Took a total of less then 30 minutes to do both engines. He took off valve covers then gauged each valve. Took like 5 seconds per valve. Then put cover back on. Kept same gasket in place.
 
I hired mine out. He charged me 2 hours labor and I was able to use the same gasket as well.
 

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