Cummins QSC 8.3 Reliability and Service

[A_8]

One of the boats we are considering have these engines and I am trying to understand the service items beyond the std oil, filters, belts, anodes etc.

I have found that the heat exchangers and charge air coolers need to be cleaned and pressure tested every 4 yrs.
Also the overhead set (tappets?) and engine brake every 4 yrs or 5000 hours.
I got the last part from the non-marine version and the engine brake stuff should not be relevant for boats?
Even if it’s needed 5000h is significant and I wonder if this is necessary to do even after 10 yrs on an engine that has done 500h, anyone know?

On reliability every indication on the web (mostly US sites) is that they are very good.

The gearboxes are ZF280 1-A and have not reaserch them fully yet but they also seem really robust and that they are more or less std on engines this size.

Generator is a Onan 7MDKBL

Any experience or info on any of the above is appriciated.

 

[5teve]

Check seaboard marine forum's at sbmar.com. Tony is a Cummins guru, and generally knows these and their service better than Cummins. Great engines but service past present and future is critical, as is engine loading and exhaust design... Latestarter on here is also a Cummins guru but is not seen to often now as I believe he is busy with engine development..

Steve

 

[volvopaul]

One of the boats we are considering have these engines and I am trying to understand the service items beyond the std oil, filters, belts, anodes etc.

I have found that the heat exchangers and charge air coolers need to be cleaned and pressure tested every 4 yrs.
Also the overhead set (tappets?) and engine brake every 4 yrs or 5000 hours.
I got the last part from the non-marine version and the engine brake stuff should not be relevant for boats?
Even if it’s needed 5000h is significant and I wonder if this is necessary to do even after 10 yrs on an engine that has done 500h, anyone know?

On reliability every indication on the web (mostly US sites) is that they are very good.

The gearboxes are ZF280 1-A and have not reaserch them fully yet but they also seem really robust and that they are more or less std on engines this size.

Generator is a Onan 7MDKBL

Any experience or info on any of the above is appriciated.

The ZF 280 was a bomb waiting to go off when bolted to the Volvo D9 , these were fitted to the Broom 450 and due to the box being on the limit of torque provided by the D9 many failed , all the 450 Broom boats were recalled and fitted with the larger ZF 325 to cope with the torque.
I’d look up the torque spec for the cumins and the spec of the ZF 280 before you buy .

 

[Piers]

One of the boats we are considering have these engines and I am trying to understand the service items beyond the std oil, filters, belts, anodes etc.
Also the overhead set (tappets?) and engine brake every 4 yrs or 5000 hours.

Tappets are at 500 hrs for the 6CTA 8.3 engine we have on Play d'eau. 5,000 hrs feels far to long to wait. Checking the tappets is a fairly easy task, although it's best done with 2 people. One to crank and one to check.

 

[A_8]

Thanks all, odd on tourque though. The gearbox states "best case" max 1110 Nm and the engine 1700 Nm. The D9 is 1630 Nm.

There must be more to this or is this as bad as it looks?

 

[volvopaul]

Thanks all, odd on tourque though. The gearbox states "best case" max 1110 Nm and the engine 1700 Nm. The D9 is 1630 Nm.

There must be more to this or is this as bad as it looks?

D9 500 chewed up the gears quite easily .