Red Hot Turbos on Cummins QSM

Spades-- Many thanks for the support and ideas

I can see that all the suggestions would have an effect on the outcome- for manifold and turbo temperature.

As we have just overhauled the engines ( including completely cleaned inter-coolers) , the gearboxes and anti-fouled the hull etc. the suggested problems around inter-cooler, cooling water etc should all be good.. but I will check them carefully as well to make sure that nothing has been overlooked. One thing that I should have mentioned is that this overheating/ glowing turbos has been a problem for some time and the extra engine room air and reduced back pressure was supposed to be the solution!!

I think the suggestion that could have most impact is to go back to the propeller design and try to determine whether we are overloading the engines... for the prevailing tropical conditions. Excessive fuel could also be a problem.. but should shop up on the analysis computer read out?

Again thanks and I will be back with any findings that we discover....

Wick

Wick, I am finally able to attach the image of a cramped installation.

Note the shielding.

One presumes the call has already been made to Cummins. What was the outcome of that call, please?

Thanks for your comment PW Slack. The contact with Cummins is difficult in Indonesia. .. the web site does not allow easy access to overseas Cummins offices.. presumably to protect dealership arrangements. We are working on it via friends in Australia to try to achieve a comment and direction from Cummins.

Is the internet controlled by the Government in Indonesia?

Bugger the website. Use the phone!

This seems to be within spec and normal operating temp....engine may be slightly overloaded or underloaded at this speed....you might experiment with slightly higher and lower speed, to match load more precisely...

http://www.sbmar.com/Engines/PDF/QSM%20Curves/QSM%20670%20Curve%20May%202010%20M-20093.pdf

If you find that this normal operation, you can consult Cummins Marine for advice on turbo heat shielding. The Cummins Marine site has documents specific to exhaust systems.

Many thanks Unredundant--- Could you please take a moment to direct me to the Cummins exhaust/turbo shielding information? I could not find it on the Cummins site!!

Our turbos glow like they are ready to melt down-- and to observe them you would consider it impossible for any oil to be lubricating the bearings at that temperature. I really do not want metal glowing red in the engine room of the vessel... it looks and feels like a disaster waiting to happen!!

Turbo and exhaust heat shields are to retain heat rather than dissipate....probably not a good idea in this application....I would go through the checklist provided here and pay special attention to the injectors....they may have installed larger flow type to increase power....

You can go to sbmr.com check technical specs. Sorry, but I can't paste the image of a QSM HO with a turbo shield installed due to issues with IPad and Cr4. Anyway, I guess the verdict is a turbo shield should not be used. I found the QSM HO is not intended for continuos duty at full load.

That's true it's not rated for more than one hour at full throttle out of 8, and less than 500 hrs per year....maximum torque at 1700 rpm.....1600 rpm should be well below full throttle and slightly below max torque....max rpm is 2340....fuel consumption should be around 12 gal per hr....How long does it run before it gets red hot? Maybe try max torque at 1700rpm and see what happens....14gph at 1700rpm....

Dear Mr.Wick,

I am of the opinion that

1. The Combustion of Fuel is continuing even after the exhaust valve is open and the Gas Combustion is continuing.

2. The Fuel Automisation is not proper, and minute droplets are carried away in the exhaust gas and continues to burn, releasing its heat and thereby Temp. is high and becomes red-hot.

A similar topic was disussed in this Forum some time back and search it out and read them. You will find lot of comments from the CR4 Members.

DHAYANANDHAN.S

Many thanks dhayanandhan.... We are investigating the fuel burn more closely now. As you imply excessive heat comes from load and fuel.
Thanks and regards wick ( Surabaya)

As "spades" noted, the props may be slightly too large or over-pitched.

Has the original boat manufacture and engine installer been contacted to see if they consider the hot turbos a problem?

If OEM knows of the issue and has designed the engine room layout to handle it and thusly has no concerns then there is likely no real problem and a lot of time effort and money has been wasted chasing nothing.

Glowing turbos during prolonged high output is not abnormal but I hear your concern re potential ignition source.....

Now I've seen flames shooting out of exhaust stacks on land based plant, that was due to the air filters being choked with bogon moths. You can't really see what's coming out of your exhaust on a boat.

The extra engine room ventilation is good but unless you direct lots of that air past the turbo housing then the turbos will still glow. There's not much air movement around a marine engine.

Thanks so to much for the input to Saniayvt
The mainfolds and turbo glow much more than looks right to me-- I understand that on some generators working hard that you might see some minor glowing ... but this is sensational and visible at all times--!!
We are looking at the possibility of installing lower rated injectors.. do you think that might help?
Best regards wick

"lower rated" injectors will squirt less fuel, you may as well just throttle back with the injectors you have. Pointless having the ponies if you don't need them and it sounds like you do need them.

Your comparison to generators is interesting as it illustrates how effective airflow is to cool the turbo body in a generator application with a big fan and radiator and a howling hurricane of air being pulled over the engine. The air around your marine engine is dead still pretty much, even though the engine room is ventilated.

When you turnoff your engines do they automatically idle to cool down for a few minutes before shutdown?

Have these/your turbos ever failed?

Many thanks to Wal and others for the input to this issue. There seems to be a general opinion emerging that this glowing turbo phenomenon is "normal" where the engine concerned is being pushed to its upper limits for rated power output. The possibilities for stopping the problem altogether seem very slim.. and where they exist--require major alterations to the mainfolds and turbos. I would very much like to see a water jacket on the manifold-- but there is zero room with this engine to fit any meaningful jacket--- and again a major alteration. Reducing load by changes to gearbox or propellers would work--but may also reduce ships speed ( which would be not a big problem as long it was a marginal reduction)

From the aspect of driving a ships hull through the water -- rather than say rotating a generator-- the crucial difference may be that this vessel once on the plane should require less load to maintain the cruising speed. There may be a "sweet spot" on the load curve that we are not achieving ---- something akin to being stuck in "3rd gear"-- pushing a lot of water in front rather than getting up on top.

The vessel was previously used as a passenger ferry in Sydney and would have been running constantly with a 150 passenger load--- say a 10,000kg load. Ambient conditions would have been cooler. I am trying to contact the previous owners and also Cummins for comment.

Best regards and again thanks for the support.

I would not expect the ambient air temperature to make much difference, as its the "amount" of the "air Flow" past the hot object that really makes a difference. a 30°C difference in ambient will otherwise never be noticeable....especially on a 700°C hot Turbo!!

In a car thats a given when driving, but not in an enclosed engine room......old fashioned boats had scoops that forced air down into spaces that needed cooling, but today, there are electric fans at reasonable prices.

Some protection from wave ingress is probably a good idea too.....

Though any engine room fan should be explosion proof and it also needs to be used to "purge" the engine room air before ever switching an engine on....standard small boat operating procedures....

Shielding the Turbo with some fireproof trunking or similar and concentrating the airflow through that may result in a dramatic difference in the heat "seen" on the Turbo, it may also take the "glow" off, but its never going to run cold.....

My Parents went on a 6 week trip to visit the family in Australia in 1969, no fridges in cars then and very hot, They drove all over and cooled the beer and other drinks simply by tying them on the front of the car. Driving at 70 MPH kept everything REALLY cold.......

"My Parents went on a 6 week trip to visit the family in Australia in 1969, no fridges in cars then and very hot, They drove all over and cooled the beer and other drinks simply by tying them on the front of the car. Driving at 70 MPH kept everything REALLY cold......."

That would actually work if you could keep the drink containers wet so that the wind chill effect took place. Unfortunately, no matter how fast you were to drive, the airflow over a dry inorganic object will only ever cool it to ambient.

The Canvas water bag used that evaporative heat loss process to good effect in days gone by, the bag was first soaked to swell the fibres so that the bag retained water, it was then hung from the front of the car where water very slowly wicked through the bag and was evaporated off by the airflow thus leaving the contents much cooler.

I must have missed it Andy, and I did say that it was the wind chill effect. Maybe you missed that, but here's an excerpt from your own link that might explain my point a bit more clearly.

"It cannot, however, reduce the temperature of these objects below the ambient temperature, no matter how great the wind velocity".

Couldn't have put it better myself.

The point is that if the ambient temperature is 40°C, then that's as cool as the drinks will get using that method - not my idea of a cool drink.

Wind chill is for people, heat engines with perspiration....nothing else...

if you burn lesser fuel you will have lesser temp. you can achive same by avoiding full throttle operation. and will have desired effect with a power loss as well.

Any alteration such as water cooled exhaust or turbo is not practical as it will reduce turbo speed and henc boost. and you again will have to reduc fuel agin and power loss which shall be irreversable.

I suspect that its quite normal. Even common or garden everyday Diesel Turbo car engines, driven quite gently at night produce a red hot Turbo. Nothing new.

Take a fast run down the Autobahn and it will glow Yellow hot!!

Thats why it has been recommended for many years to allow the engine to tick over for a minute or two to allow some cooling before switching off the engine and possibly burning the oil in the bearings. Though Full Synthetic oil is heartily recommended for such applications for many reasons.

But if you are really concerned, there are water cooled Turbos on some cars nowadays (cannot think of a model at this time, sorry!), though I would guess that the cooling system will also need to be upgraded to cope.....or a separate cooling system, could get really expensive!

Best of luck.

I found a weblink that may prove interesting for you:-

Turbochargers

I see no reference to EGT Exhaust Gas Temp you must have some meters on board for this important data. Check your EGT to see if they are in line with the manufacturer operating parameters. If you have a heat sensor gun take some readings. I assume the engine rooms are without sunlight so your turbos will glow under normal conditions. Again without knowing the EGT the source of the heat you may or may not have a problem. If EGT is high they you will have to do some root cause analysis. That for another day.

Marine engines normally have a higher rating (HP) than a engine of the same size that is radiator cooled. This is because the engine can be cooled more efficiently with the water that the vessel operates in. With that being said, if there is a problem with the vessel getting up on plain or there is some sort of undue load being applied to the engine, excessive heat is the result.

Your engines were overhauled at a relatively low amount of hours. That tells me that these engines are rated at a high level. unless, they were overhauled because of a failure.

Usually, marine engines have water cooled exhaust manifolds and turbine housings for the reason you listed. The engines are in a confined space with possible fumes or oil leakage in the area. Were these engines designed to be in a marine application?

Are the boost levels what they should be at full load?

You can verify this with a fuel flow meter. Operate the engines at the rated fuel consumption and verify that the boost level is what it should be according to the factory spec.

There are a number of things that could be causing your issues. One thing that wasn't mentioned. Did this just start doing this, or is it new to you?

If you have determined that EGT is higher than Cummins recommends then you can lower EGT with cooler intake air, less fuel and lower power or research the use of water methanol injection into the intake system.. many of my associates with high power diesel pickup trucks use this with from their perspective no negative issues. Water methanol has been used for about 50 years maybe even longer. Do some reading on the topic and decide if it is for you. Excessive EGT is and can be an expensive condition especially to the valves and turbo.

I was thinking about the same thing.

Not sure if you want to rely on it for marine use, it is another system that will require maintenance and monitoring...

Usually trouble free about same as adding Urea to a diesel as needed. My problem with helping this member is the lack of EGT info. If EGT is normal then it is all perception of a possible issue. Another issue I had on a Cummins in a Dodge was timing setting can be off usually retarded to cause hot exhaust.

I have faced similar problem few years ago and after few months work I have understand that this is normal "Red hot Turbo" with Cummins Engine. Just check few parameters like; 1. lub oil consumption is in acceptable limit. 2. Color of engine exhaust. etc.

We have water cooled manifolds for QSM11

CUMMINS ENGINES

TKS

DWIGHT

RAM TURBOS 305 7432920

Dear Mr. Wick,

Pl. open the below link where a similar topic was discussed in CR4 some time back and it may suggest to go about the issue.

https://cr4.globalspec.com/thread/84150/Diesel-Generator-Exhaust-Manifolds-Redhot

Pl. post the information what was the problem and the solution sought.

Thanks,

DHAYANANDHAN.S