12-27-2018 11:22 PM
The basic 3412 engine is very common with hundreds of thousands built however the 3JK derivative only a thousand or so.
As they are now approaching 20 years old you should consider or check parts availability of 3JK specific parts. For example the heat exchanger and expansion tank is one intergral part and therefore expensive to replace assuming if still available. the Aftercooler is not sea water cooled so this is a positive.
The seawater pump is rubber impellor and parts are readily available.
On the electronics side the following parts can stop the engine
Speed Sensor - the engine has a main and back up sensor so no concern here
Rack Solenoid (BTM) - same part as used in the 3406 truck engines so should still be readily available
Shut Off Solenoid - can be manually overidden
ECM - is ADEMII and were more reliable than current ECMs but are now 20 years old.
12-27-2018 08:47 AM
Thanks for the reply.
Apparently these particular engines had a full rebuild about eight years ago, although I don’t have any details. Approximately 3000 hrs since rebuild.
Is there anything in particular I should be looking out for on them? My only experience so far with marine diesels is with Cummins QSB 5.9 common rail engines.
12-19-2018 06:17 AM
The 3412 3JK PEEC Marine engines were and still are good engines. I was doing some work only last week on a vessel powered by two and they had 12000 hrs on them and still very reliable. The 3406 PEEC truck engines had some real problems particulary with their electronic hydra mechanical timing advance system and boost transducer and speed sensor mounted in the back of the fuel pump. Compared to the 3406 the 3412 3JK has a mechanical timing advance (same as that used for years in 3408 & 3412 engines), no boost transducer and dual speed sensors in the flywheel housing for easy access.
12-09-2018 06:09 AM
Looking for information on a pair of 3412’s in a boat I’m considering buying.
Serial numbers are:
They are 1350hp versions, manufactured around 1999.
I can’t find much on these engines, and I’m specifically interested in whether they are electronic or not.