repower 1999 4600 SCB

[tommyz]

Hi

I need a new engine on my starboard side. I have cummins 370 in there now

I have called and gotten a price on a long block, but would like to know if anyone has ever done a repower on this boat and how did you do the engines?

Assumign through the main hatch?

Tom

[shrew]

stripped down, through the main hatch. Lots of cribbing and an gantry style crane will get built inside to lower it into place. This is not a DIY project if you've never done it before.

[tommyz]

Thanks

I will have all professionally done.

any other tips on this ?

[shrew]

Originally Posted by tommyz

Thanks

I will have all professionally done.

any other tips on this ?

Take the time to clean and paint the bilge while the engine is out. Also consider when the last time the stuffing box or dripless was serviced and take care of that while it's wide open. Also consider when the shaft bearings were done. Since you're already uncoupling the shaft, consider replacing cutlass bearing.

Technically, with twins I would do the stuffing box/dripless and cutlass bearings on both sides at the same time.

[CrewRest II]

Did you finish the task of replacing your starboard engine? I may be rebuilding my port engine after swallowing a valve in the #6 cylinder. Would you mind sharing a rough cost for your repower? I’m working on estimates in my area, (Seattle).

[shrew]

Originally Posted by CrewRest II

Did you finish the task of replacing your starboard engine? I may be rebuilding my port engine after swallowing a valve in the #6 cylinder. Would you mind sharing a rough cost for your repower? I’m working on estimates in my area, (Seattle).

What year, make, model engine?

[CrewRest II]

1998, Cummins 6BTA 5.9L 370HP, 1370 HRS

[Glenn111]

May I ask, what happen to the engine....kind of low hours.

[CrewRest II]

Cruising along for 2.5 hrs @2500rpm, 18 knots, I began to feel the boat swerve to the left. I noticed the left engine was loosing power (rpm’s) and it began running rough. I brought the throttles to idle and while doing so, the left engine quit. No visible indications of fluid loss, smoke, etc. in the engine room. The cause was the #6 cylinder swallowed a valve. I’m currently in the process of pulling the head to assess the damage. Crossing my fingers it didn’t cause any cylinder damage. As you can tell by the low engine time, this being the original engine, it has not been operating much. I just purchased the boat last year knowing the engines were probably not well cared for or run much and anticipated a rebuild or repower eventually, but not this soon.

[jparsons121]

Have you checked the oil? Any signs of metal contamination?
If not, even if you have damage to the cylinder/piston they can be replaced individually.
There are piston and liner kits available, so a full repower may not be necessary.

[CrewRest II]

Yes, oil is clean. Sampled it before removing the head. I agree! Hopefully, the cylinder/piston is not damaged. I won’t re-power unless I really have to. At some point the revolving costs to repair older engines makes it worth the time and cost to just rebuild/re-power and have the peace of mind that the chance of swallowing another valve isn’t a few hours away.

[Glenn111]

Seems odd, IMO, for a 370 to swallow a valve. Is there a possibility that the exhaust design allowed salt water into the #6 through the turbo? How does your exhaust side of the turbo look?

[Cruzinblue02]

I've always heard the 4600 was underpowered anyways. Are you considering going with more power?

[Glenn111]

I believe the 46 is typically powered by 450 Cummins CTA's...not 6BTA's. I wish the 41 series also had the C's. Both are really realizable mechanical engines.