6BTA Smoke at start

[Grant Tankoos]

First post, but frequent reader – thanks for all the great info and knowledge!

Recently bought a Legacy 34 with twin 6BTA-5.9’s in her. Has been great, about 20 hrs so far and love them. Port motor has generally taken a second or two longer to fire that Starboard.

Today was our first cold day I stated the boat which had been sitting about 3. Port motor had trouble starting, cranked for 7-10 seconds. I stopped, advanced the throttle, tried again. a few seconds of cranking it started. There was a lot of smoke when she fired over and ran rough briefly… about a minute ( longest minute of my life!) it settled down and ran fine. After warming up smoke disputed to almost no existent level. Temps have always been steady.

The starboard motor smoked a bit too in the same environment but didn’t have the trouble stating nor the big burst smoke at start up… For both motors, smoke came out is seeming “puff’s”…

Any insight would be appreciated! Thanks!

Grant

Topic

[Tony Athens]

If you hook it up manual, consider a old fashioned 5 minute twist timer at the dash.. That way you cannot forget.. I like these more & more for things that you do not want to forget to turn off..
Fuse the wires going to the dash at 10 amps although 5 would probably be fine. All you are doing is turning on or off the mag switch coils that control the high current heater grids..

Also a drawing attached that may help you understand the overall schematics.

Tony

1 user thanked author for this post.

Tony Bacon

[Rob Schepis]

Tony,

When cruising the block heaters and Wolverines are not involved – they are 120V for at the dock when on shorepower.

See attached. If you want to keep your air heaters and convert them to manual usage remove the spade fuse from this holder and run your switch wires and use male spade connectors at the wire ends and plug the two male spades into the female spades in the fuse holder. Then you fuse your switch circuit up at the helm. This switching circuit controls the ECM and relays.

Do you have pan underside access to add the Wolverines?

I have my 6BTA air heaters wired exactly as I explained above and I also have the Wolverines. In the last 4 seasons of boating the air heaters have never been switched ON and the Wolverines have never been switched OFF (including winter storage on the hard)

[Tony Bacon]

Setup for Pacific Northwest climes

I believe this is my first post here. I’ve lived with diesel for a decade or so but it was a small 18hp model on a sailboat, nothing like the 6bta 5.9 M2s on my new to me 97 Bayliner. I have read your comments in various places regarding the intake air heaters on these engines suggesting removal or converting to manually controlled. What I have been confused about is air heaters versus block heaters while cruising. The block heaters make sense on shore power only, I can’t imagine running them 24/7 off my house batteries. I plan to do the manual conversion and add the block heaters so I can use the air preheat as needed to start in places I don’t have shore power, the engine struggles to start without it or I want to be neighborly to stink pot haters saving them from the aroma of white smoke (which I used to loathe). All of 4 the air heat relays need replacing (per survey), I have no idea on the condition of the ECMs. I haven’t been able to find your advice on how to wire the switches to the helm. Having read the Cummins manual I understand there are two heaters on each engine and the ECM has some elaborate scheme to control initial and post heat cycles with one or both circuits engaged depending on various inputs to the ECM. My question about wiring a manual system, am I simply supplying an on/off switch at the helm to control the entire automatic system or am I supplying on/off switches to manually control each heater relay? I’ve a hunch the prescribed solution is to install the wolverines, replace the entire ECM/Relay contraption using your $450 each replacements and run wiring to helm switches to control the entire system, not just the relays but I want to confirm that.

[Rob Schepis]

OEM Mixers

When I acquired my current boat she was installed with the OEM mixers. They were installed at 10-11deg downward angle, shy of Cummins 15deg min. spec but at least they would self drain on shutdown as opposed to the doomed risers that hold water 24/7. But even in the self-draining orientation look what the interior looked like, not pretty, and a doomed riser holding water would fair much worse. The exteriors were spotless so don’t be fooled by shiny paint. This was 13 seasons in service, always slipped in brackish water, approx 1,400 engine hours. Using all available height in the engine room Seaboard fabricated dry risers.

[Bill Desmarais]

Grant,

My previous boat was a 31 Blackfin with a pr. of 6BTA 370s.

The 370s’ mixers had the SAME configuration as your mixers, “doomed to fail”.

Back in 2009 Tony and his crew @ Seaboard fabricated new SS exhausts for the 31 Blackfin.

Problem solved !

Bill D

[Bill Desmarais]

No doubt the mixers will fail internally over time.
Both hold water 100% all the time.

[Corey Schmidt]

Risers

Grant, there are many ways to go about designing and building risers… some boat owners are very creative and can develop exhaust designs that can make the factory mixing elbow SAFE. However, if you want the most control over developing an exhaust that will outlast your engine, it’s always best to go 100% custom so it fits the boat and engine configuration.

[Grant Tankoos]

Thanks Bill for the replay and calming my concerns… I appreciate your time and knowledge

[Grant Tankoos]

Re- doomed to fail…

Thanks Cory – I suspected that set up to be an issue after going through the site before purchase. Is the only option custom elbows? The plan over the winter is to take apart exhaust and cooling system to get solid base -line and find potential problems before something serious develops… Thanks!

[Corey Schmidt]

Doomed to fail…

Grant, first glaring issue are the risers as the design will not last long…

Marine Exhaust Risers that are Doomed to Fail

https://www.facebook.com/pg/sbmar/photos/?tab=album&album_id=418154608287216

Designing a Marine Exhaust System

Any time raw water has to go UPHILL, it’s only a matter of time before the water that SITS in the riser will eat through and all go into your turbos… any signs of water intrusion yet?

[glenn111]

Any concerns on Exhaust Design ?

[Bill Desmarais]

Grant,

Bill D here.
I have a CPL 2008 (newest release) 6BTA 370 ReCon with 187 hours on it.
The engine was setup the “Seaboard Way”.
Air heater circuit disconnected and harness removed.
Wolverine oil pan heater installed.
Fuel cooler removed.

Yesterday I hauled the boat for the season.
The dock I had the boat tied up to had ZERO electricity so the engine was a “cold fire up” @ 45 F.
No oil pan heater, no air heater on startup.

The engine took 2-3 seconds to fire. The 370 stumbled, rumbled, smoke like heck for about 20-30 seconds after catching. So cold fire smoking and stumbling is all normal. With “heat” from the oil pan heater the engine fires in a revolution or two at any temp with little or no smoke.

If memory serves me the 6B family was designed to start without heat down to 15F.

All normal.

Hope this helps you !

Bill D

[Grant Tankoos]

Thanks, Tony, for the welcome and insight. I’m not afraid to admit i’m learning more all the time about these motors and still have a long way to go.

Serial numbers are : Port: 46041642 Starboard: 46043060 and attached are 2 shots of the exhaust elbows in particular that I have some concern about based on information I’ve ready here.. Appreciate the insight.

[Tony Athens]

Slow Start

Grant,

Welcome to the forum and my guess is, to world of diesels also, especially high performance ones in marine applications.

First off, there are 2 basic things that your engine needs to start.. Heat & fuel.. With that said, if one is missing, it’s no start.. Usually as winter approaches, that lack heat is the one that causes an issue as you describe.. It’s kinda a vicious circle.. Lower temps mean slower cranking speeds means less heat made in the cylinders from compression, coupled to less heat in the ambient temp. But during the process of cranking and no start, you are putting some fuel into the cylinders and finally when it does start, it can be messy for a few seconds before things clean up to where all 6 cylinders are firing well.. So, your “longest day” is really nothing that is not experienced by many or I have seen many many times.

Other things on this engine—There are quite a few versions of the 6BTA 5.9, and each has their quirks, so a serial number would be nice.. Once I have that, I can drop a few more hints that may help related to a possible lack of fuel during the slow start period..

SOLUTION: Now to what you want to do if you want a quick fix the winter starting…Install a 250W Wolverine heater pad on each engine and run them 24-7-365 when at the dock..The difference in two things will be astonishing after the first trials… How fast the engine cranks & starts, and the lack of smoke, plus another big benefit that will show after time—You engine room will stay dryer and show noticeably less signs of corrosion damage from moist air over time… IMO, this one upgrade alone will be the best upgrade you can make to any engine and engine room in a boat..

One more thing—I’d like to SEE your engines as installed in the boat.. There are some really exception “eyes” on this forum, and since this boat is new to you, puts these “eyes” in your engine room for a good look around..

Tony

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