exhaust gases manifold for two units ( no. 4, 5 ) increased the temperature up more than 500°C and a

[M Karroum]

Hello,
I'm new at this forum.

I'm the tech Manager for a General Cargo Ship equipped with AKASAKA A41 Engine / four stock/ 06 units built on 1995.

we have problem once increasing the RPM the exhaust gases manifold for two units ( no. 4, 5 ) increased the temperature up more than 500°C and all another cylinders in good condition.

We checked exhaust valves, cleaned air coolers, checked fire timing, cleaned T/C including changing bearings, gaskets, oil and seals. Still same results.
Checked fuel nozzles, compression test, economizer.
No results.

thank for your good reply

 

[MikeHalloran]

I have no specs for your engine, and no idea what the associated systems look like.

For the smaller engines with which I am familiar, 500C would be a normal-ish temperature at the exhaust manifold/turbo inlet, and a somewhat high temperature at the turbo outlet.

... which could be caused by:

- high backpressure at the turbo outlet, e.g., a clogged muffler.
- fouling/barnacles in the seawater side of your intercoolers/aftercoolers, which would also result in reduced seawater flow, and high seawater temperatures (>~140F) at the water discharge end of the cooler.

Both of the above symptoms would result in reduced power output and failure to make rated engine RPM at WOT, which I'm guessing is why the problem came to your attention in the first place.



Mike Halloran
Pembroke Pines, FL, USA

 

[chief]

Check your exhaust pyrometers, by swapping over from other cylinderss, as a first step. Also swap over or change fuel injectors.Check your turbo discharge air pressure and temperature is normal. Check the back pressure in your exhaust trunking.

Offshore Engineering&Design

 

[dicer]

And how are the temperatures being checked? Also check cam, valve timing, does this engine have replaceable cam segments?