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Regular Contributor

Re: Details on Cat 3412 engines

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.

Visitor

Re: Details on Cat 3412 engines

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.

Regular Contributor

Re: Details on Cat 3412 engines

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.

Super Contributor

Re: Details on Cat 3412 engines

Yes, that's correct. Electronic governor controls a mechanical fuel injection pump.
Visitor

Re: Details on Cat 3412 engines

Thanks.

 

Just so I’ve understood correctly - it’s mechanical pump and injection with electronic governing, as opposed to electronic injection?

 

 

Super Contributor

Re: Details on Cat 3412 engines

3JK engines are PEEC marine engines, which means "programmable electronic engine control". Engines have a pump and lines fuel system and an electronic governor.
Visitor

Details on Cat 3412 engines

Hi  all

 

Looking for information on a pair of 3412’s in a boat I’m considering buying.

 

Serial numbers are:

 

3JK01416

3JK01420

 

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.