Cat installation question

[kenJ]

CATERPILAR 3126 420HP engines in a 2002 SILVERTON - 410 SPORT BRIDGE

I do not have much time around these big engines, but I can usually figure out what I am looking at. I'm guessing there is an alternator between the engine and the transmission. Is that what the monster yellow cables are for?

http://www.commonwealthboatbrokers.c...id=11732&il=43

[WestVanHan]

If you look to the right of the picture you can see the alternator.

Get an oil analysis done and get those engines checked out if you are thinking of buying it...those engines have had issues,and are not sleeved.

Cummins are sleeved..so an in frame rebuild kit with sleeves,pistons and bearings,etc is about $1000.And a couple grand for labour.

Reman units for those are gonna be over ~$20k plus the installation costs involved with sawing the sole out of your boat you'd be looking at $50-60k.

[kenJ]

Thanks for your concern, I'm not considering buying at all. As a voyeur I enjoy looking at different boats and their installs. I don't remember ever seeing this set up. Any idea what the big yellow cables that appear to be electrical are?

[michael pierzga]

I dont know Cats. Looks like a single pole wired engine ?.... the red cable is POSITIVE starter motor and the yellow cables are Negative engine block and ships earth. if so its a poor marine instalation..... non isolated and ships earth should go from block to engine bed to earth plane. Also I see no flex coupling on the output shaft...the boat will be noisey. After water injection , exhaust must point down...200mm...to prevent sea water from creeping back into the system Stick with professionally speced MTU for power

[kenJ]

What really brought up the question is if you compare this picture with the next picture of the other engine. The other engine has a very short housing over the flywheel. The one with the yellow wires is 2-3 times longer. Makes it look like a housing for something. Perhaps it is nothing electrical and they are just using the convenient space to gang the ground wires togther.

[gonzo]

The yellow wires are the common grounds tied to the block.

[WestVanHan]

Hey Ken..so it's boat porn then? lol

Anyways I had noticed other issues mentioned and was going to tell you about the grounding.
But I felt that if you weren't sure about grounding cables- what they were wasn't important.

But having the engines checked was..maybe you learned something else anyways.