I have a Detroit 6V53t In my launch. I have recently installed this motor out of a truck. It had done 30,000km since a total rebuild on motor. I converted the motor to a marine motor with all the parts from my N/A motor. The motor itself is in great condition without any problems, but I have a tuning issue that it is blowing black smoke. This could be one of three things. Motor is not overloaded. Injectors are 5A55 (original equipment) so it is not over fueling. Not enough air. This is where I think lies the problem. I have let turbo take air directly from the cabin with no diference. The turbo is a Garrett TV6123 I have installed a boost gauge just above the blower and at 2600rpm under load I am getting 5 pounds of boost. This I feel is the problem. Turbo turns freely and spins after engine stops. No air leaks I am unable to find what the boost pressure should be after the turbo but before the blower. Is someone able to offer some advise as to what the problem could be or the boost presure between turbo and blower. Thanks
carclan,
Jan 6, 4:22pm
The blower it self should be enough to supply air under a moderate load. Make sure there is sufficient air flow into your engine compartment too. The boost pressure will be low if their is insufficient air flow to the engine. See how the turbocharger rotates with the engine shut down, measure the end float etc.
planted4u,
Jan 6, 5:32pm
Air into engine compartment is not the problem we have looked into and elimanated that.
Turbo engine is 17 to 1 compression non turbo is 21 to 1 so turbo needs to boost blower. on T engines.
Turbo spins once engine has been shut down
scoobeey,
Jan 6, 9:26pm
2600rpm might bethe prob lol. you will be super red lining ha
chebry,
Jan 7, 5:27am
Where did you get the idea 2600rpm is the ideal running speed its a Detroit not some Jappa
ralphdog1,
Jan 7, 6:56am
I am no expert, but a quick surf of the intrawebby thing tells me that a 6V-53T is rated to 2800 rpm, as opposed to the 2500 rpm of the 6V-53.
chebry,
Jan 7, 9:15am
Doesnt mean it is meant to run at maxrpm all day
intrade,
Jan 7, 9:15am
black smoke is overfueling on a diesel . http://www.youtube.com/watch!v=wq_sYfuoeJ4 wrong amount of air on this it smokes gray . you can see when he shuts off the airsupply to the correct ammount it stoped smoking . you should never use your hand nor should you run the engine like they do and that waterhose , water should go thru the engine correctly when running for longer then 30 secounds
planted4u,
Jan 7, 9:52am
This is correct
carclan,
Jan 7, 10:01am
21:1! I doubt it. The compression ratio is derived from surface area and amount of heat rejected to the cylinder walls during compression.
planted4u,
Jan 7, 12:39pm
Use google and you will see that those ratios are correct. Do You know Detroits or are you guessing!
sr2,
Jan 7, 12:45pm
You might find the compression ratio is calculated by dividing the sum of the capacity of the combustion chamber and swept area by the capacity of the combustion chamber. It??
carclan,
Jan 7, 1:39pm
Did my apprenticeship with a compay that had four of them plus twenty four years marine and industrial experience one these and engines up to 10,000 kilowatt.
red97,
Jan 7, 1:43pm
probly no help but just to jump in on the rpm debate i worked on a longliner with a detroit (450hp) and it was governed to 1900rpm
carclan,
Jan 7, 1:54pm
We are talking about two different things here. I said derived and you are talking about calculating the compression ratio. Compression ratios are derived from the following factors The ratio between the total surface area of the cylinder space and the volume of the space is such that as the cylinder dimentions increase the ratio between the values decrease. In smaller engines this means more heat is lost to the cylinder space surface during compression than a larger engine. For this reason smaller engines require a higher compression ratio than larger engines. for cylinders of identical proportions, the total area of the cylinder surfaces varies as the square of the linear dimentions, and the volumes vary as the cube of linear dimentions. I hope this clears up any mis understanding.
sr2,
Jan 7, 2:09pm
LOL; no harm intended, you may be debating at cross purposes there mate (and preaching to the converted)! Back to the OP??
planted4u,
Jan 7, 2:14pm
Cool so you will know what the boost presure should be between the turbo and the blower at 2600 to 2800 rpm. Could you tell me what that is please.
planted4u,
Jan 7, 2:23pm
Not prop as we put old prop back on and still overfeuling/ not enough air. Engine will rev to 2600 under load and 3000 no load. We have had four diesel mechanics on boat at same time and have tried all the normal stuff. I had a detroit guy look engine over and all settings and timings were corect. Engine has correct governerfitted.
carclan,
Jan 7, 2:30pm
From the Detroit book
Compression ratio std engine - 17:1 Compression ratio T engine - 18.7:1
I would take off the air box covers (scavenge space) and check for carbon build up and and general cleanliness. Then if it is ok or not remove the mechanical blower and check to see if the intercooler is blocked. If you have access to a manometer then before doing any of the above check the pressure differential across the intercooler. The engine could ofcourse be over loaded if the incorrect propeller is fitted, however the fact its obtaining full RPM sort of eliminates that.
planted4u,
Jan 7, 2:38pm
Air box very clean as had rebuild. This engine does not have intercooler. Blower rotors very clean so that would elimanate worn seals
carclan,
Jan 7, 2:41pm
Pull the fuel valves and test them, Does the engine have a scavenge pressure gauge! I really think you need to check the boost pressure and compare to the manufactures specifications.
I believe you are right but unfortunatly I have been unable to find the correct boost pressure between turbo and blower. I know that from the airbox I can check combined presure but what I need to know is as stated the boost inbetween
planted4u,
Jan 7, 2:49pm
I have a fuel pressure gauge and have 60lbs all the time so that is not the problem
carclan,
Jan 7, 3:19pm
I agree, this is only supply pressure anyway. Check the pressure in the air box under full load. It does not really matter about whether or not you can measure the boost pressure after the turbocharger as the specifications will be combined.
Since the public registrations are closed, you must have an invite from a current member to be able to register and post in this thread.
Have an account? Login here.