The Great Debate

[Airstream345]

Okay. Let me ask you a question. Would you feel comfortable making the passage from Honolulu to Tahiti on a single 6-71 NA.

One of the things that appealed to me about 6-71s when considering Hatteras 58/65 LRCs was that you could literally keep a spare in-frame kit onboard.

We ended up going from a 40' twin engine trawler (FL120s) to a 54' single engine trawler (CAT3208NA) but we chose the boat first based on it's capabilities - the single CAT just happened to come with it.

 

[Open-d]

Ford Lehman engines are reliable old school engines with no electronic engine controls. They are easy to troubleshoot and repair. Parts are very reasonably priced and readily available.

I would not have any other engine in an 8 knot single engined trawler. And many here on TF will agree.

Once the injection pump drain is modified, changing oil is a 15 minute simple operation.

I'd rather worry about stripping the injection drain port on a FL than worrying about an ECM failure.

I agree about the Lehman, but would opt for the 135hp version for that reason. I can just see me clumsily dropping or fill or drain plug in the bilge. However, a modification might be just the ticket.

 

[RT Firefly]

Greetings,
Mr. O. While Mr. MM expressed his OPINION, he was relitively polite about it. YOU, on the other hand, not so much. I VERY strongly suggest you cool your rhetoric. This is a genteel community that, for the most part, engages in civil conversation even when disagreeing with another's opinion.



You ask questions, you get answers. Agree or disagree but be polite please.

 

[RT Firefly]

Greetings,
Mr. MM. I wouldn't jump to such conclusions, just yet. He may not know what he may not know and is simply attempting to clarify what he doesn't fully understand yet. What may seem a simple question and answer to us "old hands" may not be so to him. Patience grasshopper...

 

[Open-d]

The tapped fitting with shut off valve will solve the 2nd issue you mentioned above, and for the first issue, the FL135 uses common oil in the fuel pump and engine sump as I'm sure you're aware since you singled out FL120's! No more having to change the fuel pump oil every 50 or so hours. Enjoy!

Yes, changing oil every 2 days would be show stopper for me. 135s mo better in that regard.

 

[psneeld]

The recommended change interval is all over the map. Some 50, some 100, some 150..... Bottom line...it ONLY needs changing if there is a chance of fuel dilution....and even then it can go a lot longer occasionally without issue.

 

[diver dave]

It must be twins on my next boat, a cat. Of course there are even cats out there with a single. [emoji41]

 

[slowgoesit]

Yes, changing oil every 2 days would be show stopper for me. 135s mo better in that regard.

Even if the shortest interval I've heard recommended, 50 hours, that's a lot more than two day cruising for most people. How many times have you run 24 hours a day for two of more days?

 

[Open-d]

Even if the shortest interval I've heard recommended, 50 hours, that's a lot more than two day cruising for most people. How many times have you run 24 hours a day for two of more days?

It is my intent to cover a lot of the blue pacific on long soul-satisfying passages. 50 hours would be a shakedown.

 

[sunchaser]

Even if the shortest interval I've heard recommended, 50 hours, that's a lot more than two day cruising for most people. How many times have you run 24 hours a day for two of more days?

Which raises a serious issue for some. Oil disposal. Longer interval changes is a lot "greener" as well less hassle.

I'm curious if a well running Lehman would suffer oil degradation after 200 hours or so with today's ULSD. I'd dare say 200 hours at 1600 RPM would yield a lot different oil analysis as compared to 200 hours at 2000 RPM.

Our engines are rated for 200 to 400 hour changes based upon fuel S levels, and any valid information from oil analysis. We do changes at 300 hours or seasonal just because.

 

[slowgoesit]

It is my intent to cover a lot of the blue pacific on long soul-satisfying passages. 50 hours would be a shakedown.

Well there you go, your proposed cruising plans don't appear to the norm from what I've seen here on the forum. That said, I too would prefer the 135 to the 120, if only because of the fuel pump oil change interval.


HOWEVER, there's often a however, isn't there? If I found a boat that otherwise met all our our needs, I would not pass on the boat just because it had FL 120's. But that's just me . . .

 

[RT Firefly]

Greetings,
I think Mr ps. is pretty close to the mark when he mentions fuel dilution in the injection pump oil (post #96). On our first Lehman you could smell diesel in the lube oil when changed @ 50hrs. Our current Lehmans not so. I tend to change the pump oil every 100 hrs when changing the engine oil. Never smell diesel in the oil.


Some may argue that the manual AND Bill Smith recommended every 50 hours but I attended an engine talk at Trawlerfest in Mystic CT. many years ago and Bill said the 50 hours was a misprint in the manual and that 100 hours was fine. My memory is poor BUT I remember that.


That being said, I would certainly change every 50hrs IF I suspected injector lube oil dilution. YMMV.

 

[Open-d]

Greetings,
I think Mr ps. is pretty close to the mark when he mentions fuel dilution in the injection pump oil (post #96). On our first Lehman you could smell diesel in the lube oil when changed @ 50hrs. Our current Lehmans not so. I tend to change the pump oil every 100 hrs when changing the engine oil. Never smell diesel in the oil.


Some may argue that the manual AND Bill Smith recommended every 50 hours but I attended an engine talk at Trawlerfest in Mystic CT. many years ago and Bill said the 50 hours was a misprint in the manual and that 100 hours was fine. My memory is poor BUT I remember that.


That being said, I would certainly change every 50hrs IF I suspected injector lube oil dilution. YMMV.

Is fuel pumps leaking fuel unique to this engine, or is more of an issue because it is leaking into a smaller volume of oil that is not getting as hot as the engine oil?

 

[Pete Meisinger]

We have drifted a bit off track on this one but what do you expect with such a topic as this ?

As a devoted F.L. fan I'll toss in one more comment about the Fuel injection pump, regarding oil changes. Although I really can't imagine a set of circumstances where it could be defined as an emergency. Dropping the oil plug or stripping the threads can happen.
The hole could be plugged with a dowel or perhaps some kind of "goober". If it really were an emergency like a dock fire or an angry Chief coming to avenge his "wronged" daughter. Fire it up with an empty F.I. crank! Lots of stories about people running for hours to perhaps an entire season with an empty crank case on the injection pump.

Not recommending it you understand, but in a bad situation just do it. For a short run, no harm will befall the pump.

pete

 

[BruceK]

The recommended change interval is all over the map. Some 50, some 100, some 150..... Bottom line...it ONLY needs changing if there is a chance of fuel dilution....and even then it can go a lot longer occasionally without issue.

My 120s Lehman Manual says change the oil every 200 hours.Marin had an edition which said 50 hours. In our discussion,many moons ago, we settled on 100 hours as reasonable. What others decide is up to them. My injection pumps seem fine.

 

[RT Firefly]

Greetings,
Mr. O. Diesel contamination of the injector pump oil may well be unique to the 120 Lehman as they have their own self contained oil reservoir. I suspect it's something to do with failing or worn internal seals. I don't know enough about other injection systems to comment any further.

 

[syjos]

When we were putting 100 plus hours on the engine cruising way north, and having to change injection oil while cruising, I looked at mitigating the oil change issue.

One was running a hose from an oil port on the engine to one of the ports on the side of the Lehman injection pump and another hose from the injection drain port back to the engine. Diluted oil returning to the engine may be a problem. Other problems are maintaining the correct oil level in the pump housing and the pressure of the engine oil possibly causing issues in the pump..

Another idea was to increase the injection pump oil capacity with an auxiliary oil tank. I would connect the injection pump side port to the top of the tank and the drain port to the bottom of the tank via hoses. If the top of the tank was level with the pumps side port, the oil level should be the same. The oil should circulate from the injection pump to the tank and back to the pump via convection.

A tank holding a quart of oil should reduce the frequency of oil change.

I would do this now except drilling and tapping a bigger side port is more problematic than drilling and tapping the drain at the bottom with the injection pump on the engine. Metal shavings from drilling and tapping getting into the pump housing is greater on the side.

 

[rslifkin]

Is fuel pumps leaking fuel unique to this engine, or is more of an issue because it is leaking into a smaller volume of oil that is not getting as hot as the engine oil?

I'm not sure if internal leakage is more of an issue on the FL120 than others, but because of the separate oil supply for the injection pump being fairly small, it takes very little fuel to cause a noticeable dilution problem. Probably well within what might go totally unnoticed on other engines.

 

[Open-d]

Would anyone care to opine on twin FL135s as a reliable power-plant.

I want clarify my outlook, in general, on the issue of maintenance vs operation.

Some people buy house, in large part, so they can do "projects" on them. My brother in law is like that. Always mucking about with the house and never doing any "living". I asked him why he did just buy a house that was ready to live in, and he responded, "what would be the point".

I am not like that. I bought a house to live in, to be a base of operations for the stuff of life. NOT to do projects on.

I am NOT looking for a boat/power plant so I can dabble in mechanics.

Rather, I am looking for a boat to take me on long trips. The engines etc., are necessary,, but not the rai·son d'ê·tre for me. Others may live to work on engines, but to me it is not so. I just want the most reliable, trouble free, least-demanding propulsion system I can get, for those reasons.

It is the same with trucks. Put a camper shell on it, do necessary maintenance, for sure, but that is about it. Stock as it came from the factory.

I hope this give a better perspective on where I am "coming from".

 

[RT Firefly]

Greetings,
Mr. O. Please reread post #81. ANY engine, new or used, regardless of it's reputation for reliability is never 100% reliable particularly if it's second hand. You have no idea of the history of use/abuse OR maintenance.

We've had 120 Lehman(s) for the past 25+ years and never needed a tow. I've had to change fan belts a few times, replace fuel pump, replace starter motor and some other small articles. ALL of these would have stopped me dead in the water if I didn't have the spares or know how to so the repairs.
I'm sure a goodly number TF members can relate very similar circumstances with THEIR particular power plant, be it Perkins, Cummins, Detroit, Lugger etc.


Your "comparison" of a truck engine to a marine engine is a bit of an apples to oranges deal. A marine engine "works" 90% of the time. An automotive engine "works" about 30% of the time. Think about driving that truck with the camper uphill 9 out of 10 hours a day. No downhill, no coasting. Uphill ALL day. I'm betting it may not be quite as reliable as it may seem.

 

[psneeld]

Brian Smith (American Diesel) told me a few years back that the 120 had a better supply of parts than the 135s and in general he thought the 120 was the preferred engine.

Why and by what margin...he didn't expand upon.

 

[Open-d]

Greetings,
Mr. O. Please reread post #81. ANY engine, new or used, regardless of it's reputation for reliability is never 100% reliable particularly if it's second hand. You have no idea of the history of use/abuse OR maintenance.

We've had 120 Lehman(s) for the past 25+ years and never needed a tow. I've had to change fan belts a few times, replace fuel pump, replace starter motor and some other small articles. ALL of these would have stopped me dead in the water if I didn't have the spares or know how to so the repairs.
I'm sure a goodly number TF members can relate very similar circumstances with THEIR particular power plant, be it Perkins, Cummins, Detroit, Lugger etc.


Your "comparison" of a truck engine to a marine engine is a bit of an apples to oranges deal. A marine engine "works" 90% of the time. An automotive engine "works" about 30% of the time. Think about driving that truck with the camper uphill 9 out of 10 hours a day. No downhill, no coasting. Uphill ALL day. I'm betting it may not be quite as reliable as it may seem.

Thank you for your reply.

I am fairly well versed in engineering from a theoretical perspective on powerplants from 1200psi steam plants to diesel, and even gas turbine. I am pretty sure I could troubleshoot most minor problems that would arise. It is just not my primary interest, and my hand problem (short, stubby fingers and short arms) makes actual wrench-work difficult.

Also, I am aware of the fact that marine, fixed-plant and aircraft installations usually run a much higher continuous power-setting than a car or truck (I mentioned trucks only in the context that I left all of mine stock and have no real interest in modifying them as a hobby. They get me and my cargo where I need it, and that is what I need them for - not to serve as a project of endless modifications. Sorry I didn't make that clear.

I will consider all the input I have received and continue forward. I do appreciate all the good advise. As it stands NOW, in my mind, twin FL135 is my first choice, with twin FL120s second. I will do some more research on the 120 vs 135 issue. Third would be Deere/Lugger of some model.

 

[syjos]

I want clarify my outlook, in general, on the issue of maintenance vs operation.

Some people buy house, in large part, so they can do "projects" on them. My brother in law is like that. Always mucking about with the house and never doing any "living". I asked him why he did just buy a house that was ready to live in, and he responded, "what would be the point".

I am not like that. I bought a house to live in, to be a base of operations for the stuff of life. NOT to do projects on.

I am NOT looking for a boat/power plant so I can dabble in mechanics.

Rather, I am looking for a boat to take me on long trips. The engines etc., are necessary,, but not the rai·son d'ê·tre for me. Others may live to work on engines, but to me it is not so. I just want the most reliable, trouble free, least-demanding propulsion system I can get, for those reasons.

It is the same with trucks. Put a camper shell on it, do necessary maintenance, for sure, but that is about it. Stock as it came from the factory.

I hope this give a better perspective on where I am "coming from".

I hope you have a lot of boat bucks.

If you don't want to dabble in mechanics, you will be signing a lot of checks or credit card transactions.

There is no boat engine, new or used, that is 100% as you describe, "reliable, trouble free, least-demanding propulsion system I can get, for those reasons."

And if you are planning to cross oceans, you better learn to service, troubleshoot and repair the systems on the boat in remote location. There are unscrupulous or incompetent mechanics out there, especially outside the US and Canada. And even the honest, competent ones will charge more when you are some distance from big towns or if they are the only one in town. And if parts need to be shipped $$$$$$$

For a lot of us, working on the boat is an enjoyable hobby and for me, something to do in retirement. I'd rather be working on the boat for fun than be making jewelry boxes, turning pens, building furniture or the multitude of hobbies old retired guys engage in.

 

[diver dave]

Thank you for your reply.



... I am pretty sure I could troubleshoot most minor problems that would arise. It is just not my primary interest, and my hand problem (short, stubby fingers and short arms) makes actual wrench-work difficult.



...

Modern battery tools are really impressive. Up to and including impact wrenches at the 150 ft-lb levels. But more useful on boats are the smaller ones.
At sea, Someone MUST act in some capacity as a ships engineer. Oh, and electrician. And cook. And electronics hobbiest. And IT professional. And maid.. And radio operator.. And shrink...

 

[syjos]

Modern battery tools are really impressive. Up to and including impact wrenches at the 150 ft-lb levels. But more useful on boats are the smaller ones.
At sea, Someone MUST act in some capacity as a ships engineer. Oh, and electrician. And cook. And electronics hobbiest. And IT professional. And maid.. And radio operator.. And shrink...

I agree 100%

You did'nt mention head unclogger.

 

[diver dave]

Shoot, how did I forget. And the head is likely to need the most urgent care[emoji24]

 

[RT Firefly]

Greetings,
Mr. s. "...head unclogger." I expect THAT'S the shrink's job.

 

[BruceK]

Greetings,
Mr. s. "...head unclogger." I expect THAT'S the shrink's job.

I know that`s in jest, but the ocean crosser, especially if solo, would benefit from having good mental health and resilience in adversity.

 

[Open-d]

I hope you have a lot of boat bucks.

If you don't want to dabble in mechanics, you will be signing a lot of checks or credit card transactions.

There is no boat engine, new or used, that is 100% as you describe, "reliable, trouble free, least-demanding propulsion system I can get, for those reasons."

And if you are planning to cross oceans, you better learn to service, troubleshoot and repair the systems on the boat in remote location. There are unscrupulous or incompetent mechanics out there, especially outside the US and Canada. And even the honest, competent ones will charge more when you are some distance from big towns or if they are the only one in town. And if parts need to be shipped $$$$$$$

For a lot of us, working on the boat is an enjoyable hobby and for me, something to do in retirement. I'd rather be working on the boat for fun than be making jewelry boxes, turning pens, building furniture or the multitude of hobbies old retired guys engage in.

Just trying to minimize the need for en-route repairs by picking the best combination. Not looking for perfection. Thanks for your input.

 

[FF]

"Shoot, how did I forget. And the head is likely to need the most urgent care.


NOT if its an RV unit properly installed.