Turbo's

[james]

Sorry, no pictures right now due to computer frustration and access issues on the boat. I’ve pulled the exhaust elbows off of my 6cta 8.3 400 nippon denso 1994 era engines. Inspection of the Turbo’s show zero signs of corrosion and zero tip erosions. There is a nice healthy coating of carbon, which is what I expected to see.

My simple question is, should I use this as a chance to clear the carbon off and do a quick cleaning with Brake clean???

I am replacing my stock cummins elbows proactively as I think I observed some very minor exterior dripping. New design will be 316 stainless, with a dry elbow through the 90 degree turn, and a shower head in the last 4 inches. Failure will not allow water back into the engine.

Editorial, Cummins design on those exhaust elbows is a freaking complete failure. The bolts are 10 mill and buried behind a the exhaust water jacket which doesn’t allow you to get a standard socket on it. Essentially built to be unserviceable.

Thanks for the input!

1 user thanked author for this post.

charles

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[james]

Thanks Tony!

Tony – I’ll cut an order with you folks with expedited shipping for the graphite gaskets. We are planning to put the new elbows on Wednesday or Thursday depending on shipping. My new mechanic, who is terrific, laid into me about the condition of those bolts, and I had to plead, I didn’t do it!.

Due to your guidance on BD and this new forum, I’ve become a much more knowledgeable, owner and obsessive about engine room cleanliness and maintenance schedule. As an example, tomorrow, we have rain forecasted in Florida, and I plan to spend that time in my engine room searching for the last leaks on an express cruiser.

[Tony Athens]

Your turbo is fine…………………………..Yes, you will find the the SS gasket in not very friendly to the turbo face.. The Graphite one is way more forgiving and costs less……Some type of high temp anti-seize on the bolts is a necessity.

Tony

[james]

Picture of Turbo

I observed a bit more corrosion than I would like to have seen especially around the mating corners of the Turbo and Elbow. I did not see the system installed, and have lost confidence in the mechanic who did the work as he did not put anti sieze on the attachment bolts, all were terrible to get off and one snapped off, which means I’ve got to drill it and retap it. That mechanic also only painted the sides of the Turbo’s which I can see, grrr. The tip clearances on the rotors and the rotor blades themselves looked terrific, and I’m able to get 30+ PSI out of each Turbo when doing hi speed tests (which run up to 2650 heavy). We did observe some external corrosion and signs of dripping on the port elbow, which drove the decision to replace both right now.

I also noted orientation requirement on the gaskets, with a specific side pointed to the turbo. The turbo seems to have a slight indentation to accomodate the gasket, I won’t be sure of that until I get in there and give everything a thorough cleaning with breakclean.

Thoughts are always appreciated! Thanks.

[Tony Athens]

Send that picture again

[email protected]

[Rob Schepis]

So you know what you have and it works for how you use and maintain the boat. Sounds fair. No doubt trashing those OEM jacketed elbows is always a step in the right direction…

[james]

Spill over height

Rob – I think you are talking about the height from the Turbo to the water in the waterlift and hose running to it? If that is the case, it’s just a little over 10 inches vertically and 16 inches linear. I would prefer it to be more, but it creates massive headaches for me to do so.

[Rob Schepis]

Have you ever measured the exhaust spillover height ?

[james]

New Elbows

Attached below is an image of the new elbows. The key modification is a dry pipe all the way through the 90 with a shower head pointing downwards and well below the Turbo. Any failure and gravity is my friend and takes the water away. These fit pretty close to the size of the original elbows which means installation will not be too terrible.

A better solution would have been a dry riser that went to the top of the engine room and then came down, but that would have created terrible access problems on the engines. Our utilization is port to port cruising in fair weather, and I freshwater flush every time, so I think this is a good enough solution.

[james]

wrench…

Rob – I have a 6 point 10 mill good quality box wrench, welded to an old cresent wrench, giving me a breaker bar on a small bolt. My frustration is with the mechanic who put the turbo’s on two years ago, he did not use any anti sieze on the bolts connecting the elbow to the turbo. I got seven off with out too much pain, lots of Kroil, heat and CRC freeze off, each was an adventure. The 8th one twisted the head off the bolt despite much precaution. Now, I think I’m going to have to end up drilling it out.

Tony – I just sent you a picture of the stbd turbo taken from my phone. The port side involves hanging over the top of the engine and shooting blind, haven’t gotten a good on yet. I have classic express cruiser access issues, one side pretty easy, other side ugly. I’ve been relocating as many systems as possible to make service easier, including remote oil filter (from SBMAR), relocating fuel filters with a mud/primary system (from SBMAR) mounted centerline.

[Rob Schepis]

Do you have plan drawings for the new exhaust design you could share?

As to no socket access for the 10mm bolts – that’s really not an issue as you have much better odds of getting them out without rounding the heads using a high quality 6pt box end wrench tapped with a hammer…

[Tony Athens]

Take pics of all and send them to me direct

[email protected]

we need to “see” what you see..

I’ll post them for you..

Not much any of us can offer without that..

Tony

[Philip]

Generally a healthy turbo needs no cleaning but it hard to say anything definitive without pictures.

[Author]

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