An update on the project...
Because of a bad bearing shell, they had to refinish one of the crankpins, so everything has been a little bit to busy.
BUT: The office has agreed. Next month a specialist will come to measure the complete engine. They say he will need 5 days to do all the test...
Hello guys, I'm back from the ship.
We had some more problems, a crankpin bearing has gone bad and damaged the shaft. So there was little time to do some experiments.
But as an answer about injection timing:
We take P/V diagrams and very clear P/crankangle diagrams. These shows us that the...
Hello, everybody
There seems to be a little misunderstanding about the swirl plates.
Originally, they were not installed. It was a original Mitsui modification, because they thought the fuel was not mixing with the air. Or the scavenging cycle left some parts of the combustion space with...
Hello everybody,
Thanx for your repies:
I'm back from the ship and i've got the following items:
We did tests on the injector test bench and found the average injection angle to be 124 degrees. This matches the center part of the mark on the piston. Together we searched all the books we...
DonReplika,
About my previous statement. The engines I talk about always run at the same RPM, Unloaded or fully loaded, the RPM remains the same.
When you alter the rpm of the engine evenly with the load, it can change everything. I don't know for sure.
Hello 21121956,
This is truly a educating site. I've seen and learned a lot. I will need some time to process everything :-)
Tomorrow I go back to the ship for another 14 days. I will search and find as much details about the current injection nozzles as possible. There must be some details...
Hello jbthiel, thanx for your reply
There is a swirl in the cilinder. After some years, Mitsui changed the cilinder heads and installed swirl plates at the inlet valves.
This was done to force the inlet air in the cilinder under a certain angle, and so introduce a swirl trough the cilinder...
I scanned a drawning of the engine. In the close up of the cilinder top, I've drawn in red what I GUESS is the injection at this moment. In Green I have drawn what I THINK it should be.
The red patern is drawn, based upon measuring the mark on the piston, and the estimated angle of injection...
OK Pictures of the piston with the combustion marks. The marks shows the spot where the injector puts the fuel.
Is it correct to state that there may not be a visual spot like this on the piston??
Is it correct to state that the marks are to close to the center of the piston??
Does anybody...
I finally discovered it, it was here al the time, right before my Eyes,
Picture of the ship with the obvious big black cloud, both at sea at full load and in port at part load.
For marine diesel engines (500rpm 4stroke)
A turbo camshaft differs greatly. The inlet valve opens a lot quicker and the overlap is bigger. This is because:
The inlet valve can open when the pressure in the cilinder is lower than the boost air pressure. With a turbo, this can be earlier...
Well Bill,
Thanx for you're advice, but it' s to late I'm afraid. There have so much problems in the engine room. It's now in the hands of the captain and he has decided to put it up to the office technical department.
And since I'm senior third, I will have to do the talking...
Looks like...
Hello, I'm back from the ship again. Thanx for all your responses.
I have been checking some things out, on your advices.
1. Is there a way so I can add a picture or a graphic to this board???
2. Pressure ossicillations in the measuring tube:
I've been checking this out. There are 3 curves...
I have been thinking about bad measurements. But the measurements with the same equipement on the auxiliary engines (2x 8 cylinder diesels (750 rpm) shows a clean nice graph. Both measuring points are at the indicator valvese. Both have a valve, and a length of pipe.
But the main engines...
