6v53t help please

I have some questions that hopefully someone can help with.

Quick outline is I had a 6v53n marine engine that died in my boat. I bought a 6v53t out of a truck that I converted over to marine with all the parts from my 6v53n governer included.
New truck engine had an inframe rebuild kit 15000 miles before I installed it in my boat. I am blowing black smoke that gets worse as rpm increases.

1/
How many pounds should the turbo be boosting from a take off point between the turbo and the blower?

2/ My 6v53n was specked up and had n55 injectors, My turbo motor has 5a55 injectors. What is the diference in injectors?

3/Would these motors have similar HP output?

4/ I have a 3200 no load rpm. What should my full load rpm be with this no load rpm?

Thanks in advance

turbo bost at air box 53t @2800 =38.0. 53n@2800 =6.1
hp, 53t=275hp with 5c55 inj., 53n=220hp with n55 inj
engine should run 2800 fl,

Thanks Marv

My engine has 5a55 injectors and the one you quote that has 275hp has 5c55 injectors. What is the diference as I was going from the information below.

Could you please clarify this for me.

Will the airbox presure still be 38pounds with the 5a55 injectors.
Also the above graph states my motor revs to 2500 rpm not 2800.
Please explain.

I am in New Zealand and have been unable to find any
one that knows much about detroit 2 strokes.

Thanks

Hi Marv
A bit more infomation for you
My turbo is a Garrett TV6123

Thanks
Gordon

set rpm at 2950 noload,this should give you 2800 rpm under full load. 5c55 inj is a cleaner burning. 2500 is for a industrial unit,2800 is a marine app

Not to butt in....butt,
I don't know a whole lot about the 53 but the 5a55 injector is listed as a truck 6v53t injector 79-81 while the 5c55 is listed as a truck 6v53t 82-85 injector. I worked on the 71's and 92's back then and that was EXACTLY the time that the EPA was all over DDA for initial diesel power emission regulations.

Also, I think an important consideration you should take as to max. boost and load settings would be exhaust outlet temp at the turbo. If you are tuned and burning your fuel properly, you should see about 750*f temp on the pyrometer at that location. Much higher than that, you start overheating and breaking things like valves, rings, liners. Lower than that (what you have now with all the smoke) you are wasting fuel.

Since it would appear that you have the correct injectors installed, then it comes down to are they timed correctly and are you getting enough air. Like I said, I don't know beans about the 53 but if it were a 71 or a 92, I would be looking at those factors. The first place I would start is with the blower by-pass valve. Does your engine even have one? After that, I'd pop the covers and check timing. If that looks good, it's time to start looking at the Garret and all the plumbing.

Is your old exhaust system for the na engine adequate for moving the kind of air you need to now? All you have to do is look back up at that chart and see that it's a whole new world of air flow. Same thing goes for inlet piping and filtration. If she can't breathe, she can't burn that additional fuel. Just sayin'

Hi jgmo
Thanks for the infomation. I am learning a lot about my 53 and all information is great.
The exhaust manifolds are from my NA motor but are equally as big as the truck turbo manifolds.
I constructed the exhaust from manifold to turbo myself and both are from 3 inch pipe with one 180 degree bend each. So no restriction there.
Out of the turbo it comes out into a four inch 90 degree bend then straight into a spliter and back into two 3inch pipes from there it has a very open slow bends that in total would make up 90 degrees then out through the wet exhaust system.
So I doubt a restriction there.
Inlet pipeing from turbo has two 90 degree tight turns then into manifold and that would have a45 degree bend onto the blower.
No blower bypass.
I have a boost gauge to check boost presure from the turbo on the inlet manifold before the blower and I am only getting 4 pounds of turbo boost and this is where I suspect the problem is. What should the turbo alone be boosting at?.
What should my 5a55 injectors be timed at?
My manual doesent have the tune up portion in it and I am unsure of the exact point to time the injector. If someone could post a link that would be most helpfull.

Thanks to all replys
Gordon

4" boost?! 4"inches of what? Hg? That's about 2psi. I wouldn't even call that "boost". I believe marv indicated that it should be about 38psi and I wouldn't necessarily argue with that. So, yes, that is a problem. It sounds as if a waste gate is stuck open or the turbine or compressor wheel is freewheeling. Definitely sounds like the turbo is not working AT ALL. Are you feed that baby lots of clean, fresh oil for the bearings? Turbos die quick without a good oil supply.

As for your timing, I don't have any documentation for the 53 at all. There are plenty of Detroit "hot rod" truck blogs though so I'll do some digging and you can look around too unless marv can come back and give you a proper height setting.

Here's a website I've run across a couple of times. I think if you join, you can have access to these pages with a "basic" membership. The link is for the 53 tune up.

http://boatdiesel.com/Engines/Detro...ne-Up-May-1990.cfm?PDFID=3960220221784&Page=6

One other thought I can give you is; If I were stuck on an island and wanted to get off badly and then stumbled upon a boat that had a Detroit in her and the injectors absolutely had to be installed and I didn't have a book for timing but had a timing gauge set, I would choose the 1.460 gauge. Might not be the right one but it would start and get me off the island.

Ok been away on boat for a bit going at 1500rpm so we dont blow black smoke

I have found that the 53t motor had two AR ratings on the turbo housing. One is 1.20 and the other is 1.05. I will check next time at boat if it is 1.20 and if so I feel I may have found the problem.
Could someone explain why there would be two different housings and the differences each would make in HP or aplication.
Thanks
Gordon

Simply put, the turbo and the injectors have to match. For instance: If you were to want to increase horsepower on an engine you might want to just add more fuel, right? Guys do it all the time on naturally aspirated engines...up to a certain point. At some point, you can add too much fuel by using too large of an injector and the engine simply can't burn it. There are many factors involved but the biggest one is AIR. That's where the turbo comes in. It can add more air and you can burn that additional fuel...up to a certain point. Even with a turbo, you can have too much fuel and not enough air.

But, of course, it's really not THAT simple. The A/R stands for "area over radius" meaning the sizing of the turbine housing "scroll" or "snail" and the turbine wheel's diameter halved or how far it is from the end of the turbine blade to the turbine shaft center. The larger A/R gives good "leverage" at higher gas flow but it takes longer for the turbo to come up to speed. The smaller A/R gets the turbo spinning sooner with boost pressure coming up quickly ( as in what you need to get up on plane) but can cause excess restriction to flow at higher boost pressure.

So, you see, it isn't simple at all. And, from what I've read of your posts, you don't have ANY boost to speak of. You argue that your exhaust system "can't possibly" be causing any restriction but you are just guessing. I know that sounds blunt but if you are serious about figuring out what is going on here you will need to do some basic testing and that involves using some gauges or manometers to MEASURE what is actually taking place.

This might help

Finaly got my engine sorted.
After nearly 400 emails I was able to source a TV 6302 rebuilt turbo. It helped my black smoke problem but didint completly cure it.
I replaced the 5a55 injectors with N55 injectors that were in the old engine and this cured my smoke problem problem. The diference in injectors is minimal.
Obviously the injectors were not rebuilt at time of recondition.

Thanks to all who tried to help

Glad you got it! With all that you had to learn sorting it all out, you are the "answer man" now!