Long way from home - need some advice

[captmikem]

The breather was in fact clogged. After it was cleaned the back pressure was reduced but is not eliminated. Looks like we can run at reduced RPMs and closely monitor in the hopes of getting back to NC and addressing bigger issues then. Thank you everyone!

Key west to NC is not a long way, even if you take the intracoastal. Have a good trip.
M

 

[Frank Tew]

Had an issue with one of our two engines. Have an expert coming tomorrow to give us advice. Initial feedback from knowledgeable people is that the engine needs to be rebuilt. We are in the Keys and our home port is in NC. One suggestion was to run home on one engine (we can bring the second engine on line for short time at lower RPMs like maneuvering into the dock ). Anyone ever done a long transit on one engine? Would obviously feel better about doing major work in our home port with people we know, but that is a lot of water to cover. Thank you!

My understanding is if you elect to do this, you need to fix the prop shaft on the engine that is not running so that it does not turn this way it does not damage the gearbox.
I'm no expert but I lost a Twin Disc gearbox due to this. I've been told that if you have room, you could wrap a rope around the prop shaft several times and tie it off to a motor mount or something fixed.
There may be others with more experience that can comment.

 

[Flatswing]

In terms of long run on one engine, I think it’s worth checking how the shaft seals are cooled. Do they rely on water fed from engine driven cooling? The prop will still turn on the non-running engine from motion through the water, so the seal could get hot over time…

The issue running in 1 engine is what do you transmission builder recommend.

I can tell you from experience that running a trawler at 7-8 knots in FL (warm) water for hours on 1 engine will not heat up the non-driven but spinning PSS shaft seals - even without crossovers. Mine never budged above ambient.

 

[rslifkin]

My understanding is if you elect to do this, you need to fix the prop shaft on the engine that is not running so that it does not turn this way it does not damage the gearbox.
I'm no expert but I lost a Twin Disc gearbox due to this. I've been told that if you have room, you could wrap a rope around the prop shaft several times and tie it off to a motor mount or something fixed.
There may be others with more experience that can comment.

It depends on the transmission. Some are fine to freewheel indefinitely at lower speeds, some are fine for a few hours, but need the engine started periodically to circulate the oil, some are fine provided the temperature stays below some limit, and others say not to allow freewheeling at all. Best to check what your transmission manufacturer suggests before deciding on the best way to handle it.

 

[CaptRowlands]

Third or fourth vote to talk with Brian at American Diesel. He KNOWS these engines and may be able to refer you to reliable mechanic in SFL.

 

[chusansail]

Had an issue with one of our two engines. Have an expert coming tomorrow to give us advice. Initial feedback from knowledgeable people is that the engine needs to be rebuilt. We are in the Keys and our home port is in NC. One suggestion was to run home on one engine (we can bring the second engine on line for short time at lower RPMs like maneuvering into the dock ). Anyone ever done a long transit on one engine? Would obviously feel better about doing major work in our home port with people we know, but that is a lot of water to cover. Thank you!

I ran from sc. To Newbern on one lehman 120. Tranny went on other one. Bit awkward going slow but easily doable

 

[omoore]

Had an issue with one of our two engines. Have an expert coming tomorrow to give us advice. Initial feedback from knowledgeable people is that the engine needs to be rebuilt. We are in the Keys and our home port is in NC. One suggestion was to run home on one engine (we can bring the second engine on line for short time at lower RPMs like maneuvering into the dock ). Anyone ever done a long transit on one engine? Would obviously feel better about doing major work in our home port with people we know, but that is a lot of water to cover. Thank you!

I have a GB 42 with twin Lehmans and I live in New Bern. I have never found anyone here I would trust with a rebuild. That said, South Fl. is the Mecca for expert engine service. There is everything from distributors, to dealers to independents. Check with Brian by all means. Then I would contact this place Home - Florida Keys Marine Diesel LLC The company has a good reputation with high end diesels.

 

[SteveK]

We did remove the oil fill cap and run it. No smoke and the same back pressure. So good thought, but didn’t yield a solution.

OK, but did it stop or slow the oil out of dipstick. If not, then I would remove some oil. Not smoking suggests overfilled to me.
Before each new run I check fluid levels. My levels have been the same since last oil change, both near the 1/2 mark area, both suggesting they want oil. When I first got the boat I filled to the full and it would get rid of the excess, now all is well, I know the level they want.

 

[Moonfish]

We did a two day run home on one engine a few years ago. Twin FL120s with Velvet Drive transmissions. From my research back then, those trannies can freewheel just fine. Running on one engine wasn't a problem, though we did opt not to anchor in a crowded anchorage the one night due to limited maneuverability.

 

[BVrolyk]

It sounds like excessive pressure getting past the rings. Discovering that your crankcase breather was clogged up is good news, and probably explains the oil being pushed out the dip-stick tube. If the crankcase breather is still partially clogged and the rings are worn badly, even a partially clogged breather can cause your problem. There are more drastic failures that could cause this. For example a cracked piston or one with a hole burned in it. But those are rare. A simple compression test could tell you which cylinder has the problem.

Simply put, the engine needs to be torn down, but in the mean time the key is to allow air to escape from the crankcase.

 

[Panama Dave]

I have SP275s in my boat. They were both doing the same thing. They had multiple worsening oil leaks with oil coming out of the dipstick at the end. The PO had built a DIY airsep system. I rerouted the crankcase breather tube to the turbo intake and all my oil leaks vanished.

 

[bykpjfk]

Had an issue with one of our two engines. Have an expert coming tomorrow to give us advice. Initial feedback from knowledgeable people is that the engine needs to be rebuilt. We are in the Keys and our home port is in NC. One suggestion was to run home on one engine (we can bring the second engine on line for short time at lower RPMs like maneuvering into the dock ). Anyone ever done a long transit on one engine? Would obviously feel better about doing major work in our home port with people we know, but that is a lot of water to cover. Thank you!

I brought my Mainship home to Stuart, FL a couple of years back from the keys. It was narly offshore, so it was up the ditch. No major problem but did require preplanning at bridges that you need opened. There were spots in the ICW where I could not turn around on one engine, at least not without making a 7-point U-turn.
My seals have a crossover, so if one engine is running, both seals are cooled, and my transmissions, ZF's, are rated to be rotated without the engine running. Best of luck.