[David Marchand]

Could be it. The boat did sit idle for some time before George bought it. Will grease the rudder bearings up and see how that works. Maybe also heat the shaft a little, not enough to affect the packing and see if that doesn’t also redistribute the grease.

David

[David Marchand]

I am a retired chemical engineer who spent a few of his early years in the industrial chemical cleaning business. Hammerhead seems to be no different than any of the more popular ones like Rydlyme or Barnacle Buster.

All of their claims are more or less BS- safe on aluminum is particularly BS, so is environmentally safe.

I have tested BB and unlike the inhibited HCl we used in my former business, this has no inhibitor so will corrode metals a bit. But the raw water system has corrosion resistant metals: cupronickle tubes and bronze end caps so that the metal loss is tolerable. But I wouldn’t clean your system every year with the stuff.

As far gaskets. One mistake can cost you your engine if salt laden sea water gets into the after cooler air side. Less disastrous for the main heat exchanger, but why risk it. Use Cummins gaskets.

David

[David Marchand]

Thanks guys. Yes I figured a clean plane was the most important thing here.

On the exhaust the pics show the riser going up about 3-4″ straight out of the turbo unlike most bad exhaust systems I have seen where they immediately turn down and then into what is hoped to be a self draining injection elbow. So it looks like at least someone knew to do something right. I can’t tell height above the water line until I see it for myself.

A pic from the listing showing the elbow is attached.

David

[David Marchand]

Yes, definitely 6BTAs or at least that is what the engine survey says ;-).

Another question. The engine survey showed that they would only reach 2,850 at wot, presumably photo calibrated rpms. So definitely over propped and I have told my buddy to find a good prop shop (know one in central LI?) to take about 2″ of pitch off of the props.

But for now on this 300 NM delivery would I be ok to run them at 2,400?

Oh and he got a newish NL genset to top it off.

David

[David Marchand]

Thanks Rob. Yes I would definitely think the 500 is undersized. I was guessing 1000 but didn’t know about the 900. The engine survey doesn’t say, but my next step is to call him and ask if he remembers.

My friend got a pretty sweet deal: A Searay 410 which comes with 7 liter Mercruisers but was repowered with a pair of 6BTAs all for the gasser price.

David

[David Marchand]

Rob:

I don’t know much of the story, but here is what I do know as related to me by my friend:

On the first sea trial the engine over heated immediately and they immediately returned to the dock. That engine has a three way valve on the sea side of the strainer (so you can use the r/w pump as an emergency bilge pump) and it apparently was partially closed. Later it was opened or so my friend believes as the handle is very loose and sloppy and just setting it at 90 or 180 degrees doesn’t tell you much and no one seems to know to look at the stem position.

But anyway another sea trial was done and it also over heated but not as badly. As far as my friend knows there was no significant work done as a result of prior over heating events, but who knows for sure.

Given the prior over heating event that caused the bronzing of the casting and the over heating at the sea trials it does seem like a comedy of errors and perhaps deceit. At this point I would counsel my friend to not believe anything other than what he can verify with his own eyes or with trusted pros. Based on your advice I now have more confidence in the Yanmar technician he hired to make the second sea trial who identified gross prior over heating due to the casting’s bronze color.

At this point I am suspicious of the whole deal and have advised my friend to walk away. There is more wrong with the boat than just the engine: all port lights leak, the prop cavitates badly, etc.

David

[David Marchand]

Tom:

I totally agree. I advised my fellow boaters with the same boat and engine as mine to replace the injection elbow every ten years. But did anyone listen?

David

[David Marchand]

Thanks Rob and Steve for your replies.

Rob: Sorry I misspoke, that is the coolant tank and I had forgotten that it is integral with the exhaust manifold. That and the uniform bronze color of the turbo housing that you showed does indicate that it was BBQd as you say at some point. If it were caused by r/w failure that boiled all of the coolant out suddenly wouldn’t that melt the exhaust hoses, lift muffler, toast the turbo, and lots of other catastrophic issues. If it were caused just by loss of coolant wouldn’t it blow the head gasket, warp the head,…..

Steve: I am quite familiar with that engine and its installation on the Pilot 34 and you are right, it is doomed to fail, not to mention the riser being only 8″ above the water line. I fixed both of these issues on my boat by increasing the riser height to 16″ and rotated the mixer downwards so it is self draining. For several years I was on a crusade to let other Pilot 34 owners know of this risk but I think only a few have done anything about it. Fortunately the Yanmar mixer is stainless steel so it has less risk of corroding out and the riser height apparently doesn’t often cause problems.

David

[David Marchand]

Well, I agree with all that has been said above as long as it applies only to the after cooler. Yes that one needs routine servicing as failure of the o-ring joint will let salt water into the engine.

But for all of the other salt water coolers- the main heat exchanger and oil coolers I do think monitoring engine temp is a good way of predicting need for service.

David

[David Marchand]

Actually those pics show external rust and corrosion to me. Maybe due to salt water spray from some leak or just a high humidity engine room. So they may not represent what is inside.

So pull one off, remove then end cap and look at the shell to tube sheet seal that separates sea water from air. If it is also corroded then Rob is right- high probability that the cores are frozen in place. But you might get lucky!

David

[David Marchand]

Tony:

I helped the owner move the boat 350 miles from Md to Ny and now someone else is helping him move it up the Erie and Oswego Canals. I will contact him to message me some pics.

But the upper helm, the one with the excessive locks and some light binding, is definitely a Seastar 1.7 cu ft pump. The ram is a two hose pass throgh rod type with no labeling.

David

[David Marchand]

So, here are the results of using Tony’s more rigorous advice:

The distance between the ports is close to 10″, so subtract 2″ to give a stroke of 8″. The ID is 1.5″ based on an OD of 1.75″. This gives a gross cylinder volume of 14″. Then the rod volume is about 2.5 cu in for a 5/8″ rod, leaving a net volume of about 11.5″.

Then if you take the known upper helm spec of 1.7 cu in per rev, that gives you a lock to lock number of turns of about 7.5.

The real numbers is closer to 10+. So does that mean that the upper helm pump is just worn and leaking a lot of fluid. Changing it out to a new 2.4 cu in per rev pump would give a lock to lock of about 5.3 which would be great.

What do you think?

David

[David Marchand]

Answers below:

Bill Fuller wrote:

David,
I think you need to measure the diameter of the ram shaft and the total length of throw of the shaft to do your
calculation.
That should give you the amount of fluid required to move the rudder through its total travel. See the picture.

I did measure and that is how I got a cylinder volume of 16 cu in. Here it is: The OD is 1.75″, so I suspect the piston is 1.5″. The distance between the inlet nozzles is a bit more than 9″, so figure a ram stroke of 9″. 9*(.75)^2*3.14 = 15.9 cu in. 15.9 / 6 turns lock to lock plus 10% = 2.9 cu in per rev.

A few questions.
When you turn the upper helm to the lock does it go to a totally hard feeling or is it spongy?
Can you continue to turn it with some effort?

Both upper an lower helm go hard at end of lock.

When you turn either the upper or lower helm, does the other one move? No
When making hard turns under fairly strong power does the helm feel like it is sort of chattering or slipping?

The lower helm is smooth although stiffer than the upper. The upper does seem to bind just a little and release as you turn it. I had thought that this was mechanical wear on the pump vanes.

And of coarse, has the helm been bled of all air? Actually both helms. Haven’t been bled.
Can you post some picture of both helms and the ram?

I am not on the boat, and it will take a while to get pics.

In summary, the upper helm is much looser than the lower and takes almost twice the number of turns to go lock to lock. That is what lead me to conclude that the upper pump when it was replaced was replaces with one that was too small.

Your thoughts?

David

[David Marchand]

99% of sailboats with engines like yours use a Racor primary filter followed by the engine manufacturer’s on engine filter. Usually they are set up with a 30 or 10 micron for the Racor and then the on engine filter is typically 2 microns.

These have worked well for ages.

An enhancement is a dual Racor system which Racor sells as a package with all plumbing and valves. Or you can plumb your own. This makes switching in a new filter when you have problems easy.

Although I don’t see any problems with a very large capacity Fleetguard filter system, I don’t see any advantages either assuming that your fuel tanks are reasonably clean.

David

[David Marchand]

Kevin:

A few observations:

An AGM battery with a CCA rating of 800 probably has an amp hour rating of 80. You have three in your house bank so the total amp hour capacity is about 240. A rule of thumb is that you shouldn’t charge batteries at more than 25% of their amp hour capacity although some say that you can up that to 50% for AGMs.  So that means that one alternator putting out 100 amps is almost all that you can charge with effectively.

From your description one alternator is charging the house bank and the other is charging the starting batteries- two, presumably one for each engine. I wouldn’t worry about meeting the rule of thumb for the starting bank because they usually don’t need much charging.

It is fine to have two different alternators, particularly if they are split between the house and starting batteries.

And you don’t have to buy an expensive Balmar alternator. Leece Neville makes high output alternators that fit the Cummins mount and have terminals for external voltage regulators. But the standard Delco 22si that came with those engines will also work fine to charge the starting batteries, although it won’t work with an external regulator.

David

[David Marchand]

And do you have the recommended 12″ or greater from the waterline to the bottom of the dry part of the elbow/mixer (the spillover point). It looks like you have room to add height if you don’t have 12″.

David

[David Marchand]

With the white smoke going away shortly after startup, you can be pretty sure that your injectors are fine.

While I agree with Tony’s recent post, I still wonder if there might be some reason your engine isn’t making its 370 rated hp and that is why it is smoking. First confirm governor performance by opening the throttle to wot in neutral. You should hit 3,700 rpm, the high idle spec. If not then investigate your governor/fuel injection pump. You previously said that the throttle hits the stops, but check again.

Then look at what might be causing the engine to produce less than 370 hp at wot. If the after cooler is fouled on the air side, the engine won’t get enough air at wot but it will get maximum fuel and that causes black smoke.

Another cause is that the turbo housing has corroded, the blade tip clearance is high and the turbo isn’t putting out full air at wot and the same thing happens as with a fouled air cooler.

Here is what I would do: Read Tony’s Tips on this site, first the Cummins one about 6BTA after coolers as it has text and then the Yanmar one for pictures. Then service your after cooler accordingly. If you see the fins on the air side fouled with soot and oil, then that may be your problem.

Then pull off the elbow at the exhaust exit from the turbo charger and look inside. You should see a smooth surface with a light coating of soot on the turbo throat. Any roughness is a sure sign that sea water has backed up from the exhaust. You will have to replace your turbo and rework your exhaust if this is the case.

Once you have done these things you can be pretty confident that your engine is putting out its rated hp. If you are still getting black smoke at cruise, then reduce the prop pitch an inch or so which should let the engine breath better at cruising rpms. You can cruise at 2,800 or a little more if the engine revs to 3,450 at wot to get back your cruising speed with the lower pitch.

David

[David Marchand]

Clarke: 3,300 is not high idle for that engine. 3,300 is where the maximum hp is produced. See the attached bulletin from Yanmar.

OP: I have the same engine on my Mainship Pilot 34 but no EGT gauge and run her the same way- cruise fast at 2,700 rpm. I am a little over propped- 3,250 at wot down from 3,350 when newer and lighter, all phototached rpms. But I have no soot, so it would seem that your soot is not related to propping.

What is the engine like at idle when cold. Mine puts out noticeable white smoke that diminishes when warm but not entirely. I attribute that to injectors, but I am mindful of Tony’s advice that injectors usually last for thousands of hours and I only have 1,000 on mine. It may be just the way that engine is.

Those props specs in Yanmar’s bulletin are really conservative. I think you are where you should be at 3,350 IF THE ENGINE IS REALLY PUTTING OUT 370 HP. I agree with Clarke’s list of things that can cause black soot, but they all also cut down on maximum power. So maybe you are under propped (relative to where you should be if the engine can put out 370 hp) which lets you hit that rpm but you are really putting out less than 370 hp for one of the reasons Clarke indicates. Also repitching the prop to 3,450 might be worth trying.

David

[David Marchand]

It sounds like you may have multiple causes and problems ganging up on you. Here are some thoughts:

Hard starting can be caused by air in fuel lines, cold weather or low compression. If when the engine starts it blows a big cloud of white or grey smoke out, that is an indication of compression or cold weather. Cranking and then suddenly starting with no grey smoke indicates air in fuel. You could do a blowby test to confirm low compression- see Tony’t Tips, but unless you are burning oil I wouldn’t worry too much.

High EGTs are an indication of low air or compromised air cooling, but that doesn’t seem to be the case, except for turbo problems that might cause low air flow. You may have a draggy turbo which is limiting turbo performance. Does the engine put out black smoke at high loads?

Scale inside the turbo. Well the most likely cause is sea water backing up into the exhaust due to a poorly designed exhaust system. Another thing is that if you had 2 quarts of seawater in the sump due to a leaking after cooler then another 100 quarts may have passed through the engine and out the exhaust. That might cause corrosion in the turbo, but you said it was the other engine, so ??? It could also have caused ring wear/corrosion which is why your starting is hard and compression is low.

Lot’s to think about. The only thing that I would immediately check is exhaust design. Look in Tony’s tips for proper criteria- 12″ of spill over height above the water line.

David

[David Marchand]

Paul:

Again, please measure the alternator’s output so we can see what is going on. With only 15-20 amps of DC load,  you do not need a bigger alternator. You might need an external regulator though.

So, beg, borrow or steal a clamp on DC ammeter. Load the DC system up normally and measure the current at the alternator’s terminals. Also measure the voltage at the alternator as well as at the batteries.

David

[Author]

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