John Deere?

[dhmeissner]

What do you think of replacing a FL120 with a John Deere? I'm thinking of this as something that might interest me in a year or two when I retire and can refit The Promise to a higher standard so we can cruise long term without worry. The displacement is 14,000lbs so a small JD might be the ticket.

Engine
PowerTech™ 4045TFM75
Displacement
4.5L
kW/hp
101 kW (135 hp)

Could be a good match? I will have to see what that would cost I guess, might have to log some trees to pay for it.

 

[Xsbank]

Is the Lehman toast? Way cheaper to rebuild it than replace it. Industrial Engines can sell you a rebuilt Lehman; the Canadian dollar sucks.

 

[Insequent]

Sure it will cost. But JD make fabulous engines. I have the 6068 TFM75 now and love 'em. Once you've done the 100 hour break-in at high power you can just run them at lower rpm and they sip fuel. Not saying the Lehman's are fuel hogs either, but I suspect the JD's will use less.

One of the money saving tricks is to get your repower engine to match existing gearbox ratio and prop size. The Boat diesel calculators worked well for me. I went from Cummins 270HP at 3000rpm to JD 201HP at 2600rpm, and did not even have to tweak the pitch to get full rpm at WOT and the dealer to sign off for warranty.

 

[FF]

For a repower I would purchase a factory rebuilt 4 cylinder from the TRACTOR folks.

3 or 4 times a year they go on sale and no donor block is required.

I would match it up to a rebuilt twin disc and plan on cruising >forever<.

Ideally I would convert to keel cooling , and only use water for the aftermarket exhaust manifold, although a dry stack would be first choice.

Adding a thrust bearing and using really soft mounts and one of the shaft drives could reduce the noise and vibration to almost nothing.

The use of used rebuilt would easily pay for the extra parts compared to purchasing new from a Marine JD guy.

 

[Marlinmike]

I certainly like the John Deere product, not sure as another posted stated would toss the Lehman for a turbo inner-cooled 4 cylinder diesel, now there are other brands that I would do that swap with, just not sure in your case.

 

[Capt.Bill11]

How many hours on the Lehman you currently have?

 

[twistedtree]

I sure hope the Deeres are good - I've got two of them now But they do have a good reputation. The 4045, as the number implies, is a 4 cylinder so likely to be physically smaller than the Lehman which you might find handy.

 

[Larry M]

Four years ago we looked at the cost of repowering Hobo's SP135. Rebuilding was ~10K if we pulled and reinstalled the rebuilt. A new Lugger/Northern Lights was ~40K. Here's a thread discussing repowering the SP135. Take a look at Post #7 which goes into some detail. For us, if and when, we'll rebuild the SP135.

http://www.trawlerforum.com/forums/s6/replacing-ford-lehman-sp135-2263.html

 

[rwidman]

It would be far simpler and less expensive to rebuild the current engine or replace it with an identical one.

 

[Mule]

You might check e bay. 6BT Cummins brand new $ 10.5k. A 4BT might be better for you though. did not see any new 4's though, still have to marinize either of them so another $6-$8k on top of. A 105hp Kabota by Beta gets up north of $20k....be perfect but the tariff, ouch...still better than chasing a $30K+ Deer. Have you considered having a mechanical survey done. Oil testing every 25 or so hours, having a full out evaluation of your existing engine. Perhaps top end overhaul is all you need, maybe you need nothing. Lay back spares like alternator, starter, raw water pump, water pump, fuel pump and so forth and call it done. Ford L. Engines should go 10k hrs before top end overhaul and 25k hours before a major. I have a FL 135 super. 2k hrs, runs like a top at 33 years old.
Another way to go is, sell your boat and start looking for a better boat and spend the money that way, perhaps you will find a fool like me that has $100k in a boat he has refit that you can buy for 1/3 of that. I have a 34 Mainship with a 6bt repower, the 2nd boat that someone is gonna get a hell a deal on.
With my limited experience, never again would I get into a major refit. Anything more than a valve job, if discretionary, would be off the table. Good luck with what ever you do

 

[bobc]

What do you think of replacing a FL120 with a John Deere? I'm thinking of this as something that might interest me in a year or two when I retire and can refit The Promise to a higher standard so we can cruise long term without worry. The displacement is 14,000lbs so a small JD might be the ticket.

Engine
PowerTech™ 4045TFM75
Displacement
4.5L
kW/hp
101 kW (135 hp)

Could be a good match? I will have to see what that would cost I guess, might have to log some trees to pay for it.

I've done exactly what you're asking. It was expensive, but I don't regret the decision.

The only thing I would have done different is go with the non-turbo model. the 4045TFM75 has more power than I need with my displacement hull. The biggest reason for wishing I hadn't gone with the turbo was that I ended up having to replace the exhaust system with 4.5" plumbing. We couldn't get the back pressure low enough with 4" plumbing. The second is that, at normal cruising speeds, the turbo isn't working very hard, so I open it up (and suck fuel) on every trip just to make sure that the exhaust temperature gets hot enough to keep the turbo happy.

I can't really hear the turbo, and I did enough research to convince myself that modern turbos are pretty reliable. I suspect I also get a bit better fuel economy, Though I had to pay for that economy.

The engine went in with only a few minor stringer modifications. So that wasn't too bad, but I ended up having to replace both the transmission and the prop. You'd probably also have to replace the transmission, but the prop situation was unique to me.

I had to redo the fuel system, which needed to be done anyway. The lines were old, and the return system wasn't really up to the task given the much greater fuel return rate on the JD. The FL just trickles fuel back to the tank.

I had to put new seacocks and strainers as the old ones were too restrictive to meet Deere's warranty requirements (same story with the exhaust). Which brings up another point. To get the warranty on the engine, JD requires a sea trial where things like exhaust back pressure and seawater flow rates are measured. I don't know if that's something you could do yourself. You'd want to check with JD.

The engine is quite a bit shorter, so I had room to add a separate start battery in front of the engine, between the stringers. Now my 8D's are just for house use, though I can switch them in for starting if needed. This involved wiring in a new Bluesea ACR. Before I had to keep and 8D in reserve, so I've doubled my house capacity.

I could have rebuilt the Lehman, though that would have cost me an entire boating season. So my remaining choices were to install a rebuilt Lehamn, install a new American Diesel, or go with new technology. The first two would have been much cheaper, but with the newer engine, I suspect parts will still be available 10 or 15 years from now.

The 4045 is counterbalanced, and is actually quite a bit smoother than the FL120. The JD is also a very clean engine. No soot on the transom, and no smoking when it's cold.

There's a great peace of mind that comes from knowing that my 1974 boat is mechanically new.

 

[Nomad Willy]

I agree w mule here and certainly wouldn't rebuild a Lehman. Not at 10K anyway.

If you have an over powered boat (and most are) don't overlook the chance to repower w the ideal amount of power. Buying new things for one's boat is expensive but the reward is getting exactly what you want.

MER equipment in Seattle did sell a JD that was engineered to be a drop in replacement for the Lehman. I think they have my favorite steel exhaust manifold. Don't know enough about them for a recommendation though.

Also try Klassen engines in BC or Yukon engines in Ballard at the Hatton store on Leary Way by the Salmon Bay Cafe. Ask for Dave or Jim S. I do recommend Yukon.

 

[dhmeissner]

Thanks for all the thoughts on this guys. All good points to consider. My FL120 has under 2k hours, smokes a bit but runs and sounds good to my ears. I will have an analysis done. Still in the planning stage.

 

[markpierce]

I believe my non-turbo 4045 is John Deere's smallest maritime engine at 80 horsepower. It idles at just under 800 RPM and WOT is 2400 (U.S. smogged). It's a good engine but I have less than 400 hours on it. At cruising speed get 1.5 to 2.0 gallons per hour (4.0 gallons at WOT) pushing my 14-ton, FD boat, but hull speed is reached before 2200 RPM.

The model you list is a turbo. Do you need the extra horsepower?

 

[Marlinmike]

markpierce real nice installation!

I believe my non-turbo 4045 is John Deere's smallest maritime engine at 80 horsepower. It idles at just under 800 RPM and WOT is 2400 (U.S. smogged). It's a good engine but I have less than 400 hours on it. At cruising speed get 1.5 to 2.0 gallons per hour (4.0 gallons at WOT) pushing my 14-ton, FD boat, but hull speed is reached before 2200 RPM.

The model you list is a turbo. Do you need the extra horsepower?

 

[Capt.Bill11]

Thanks for all the thoughts on this guys. All good points to consider. My FL120 has under 2k hours, smokes a bit but runs and sounds good to my ears. I will have an analysis done. Still in the planning stage.

Only 2000 hours, that's nothing. Quite frankly you'd be crazy to replace it for no good reason. But it's your boat and money.

As to the smoking, what color is it? Does it go away or get better as the engine warms up?

 

[markpierce]

markpierce real nice installation!

Thanks. The port and starboard battery boxes are convenient for sitting when servicing the engine.

 

[dhmeissner]

Mark that's real nice looking.

Bill, I hear ya. I won't be jumping in too anything too soon. The smoke is grey and never leaves, it's not excessive but there no the less. I'm going to have a mechanic look it over soon.

 

[sunchaser]

You might check e bay. 6BT Cummins brand new $ 10.5k. do

A 6BT Cummins reman has a new engine warranty, less vibration than a 4 and non electronic. Less money than a JD and same footprint as the Lehman. Parts everywhere if the need arises, as it is the most popular diesel made during the past 20 years.

Ask this same question on boatdiesel.

 

[psneeld]

You might check e bay. 6BT Cummins brand new $ 10.5k. do

A 6BT Cummins reman has a new engine warranty, less vibration than a 4 and non electronic. Less money than a JD and same footprint as the Lehman. Parts everywhere if the need arises, as it is the most popular diesel made during the past 20 years.

Ask this same question on boatdiesel.

While a lot of that makes sense...what's the lowest HP the block puts out?

 

[sunchaser]

You might check e bay. 6BT Cummins brand new $ 10.5k. do

While a lot of that makes sense...what's the lowest HP the block puts out?

The 6BT remans are rated at 220HP, with the same block built at 115 HP years ago. The 6BT will operate all day quite happily at 1400 to 1600 RPM drawing whatever the throttle setting calls for, say 50 to 60 HP. Many 6s do the same. My Perkins Sabre225 TIs/Cat 3056 operate quite nicely at 40 to 60 HP each day in and day out with the odd time going to 150 HP each as sea conditions or passage making needs dictate.

 

[markpierce]

My engine mechanic says he rarely sees 4-cylinder JDs as compared to the 6-cylinders. But do I care as long as he looks/cares after mine? Do trawlers need so much horsepower?

No doubt, it depends.

 

[Insequent]

The JD 4's are now supposed to be smoother than the 6's due to the wonders of CAD, modern manufacturing and balance shafts. Certainly the old rule of 'always choose the 6 for smoothness' is no longer a given.

When repowering I decided that I did not need to travel at 16 kn (more to the point I did not want to pay for the fuel...) so I downsized from the total installed 540HP. At WOT it was kinda planing but needed help from the trim tabs. So, struggling a bit. I now believe that something like 800HP in total would be the right option for high teens travel in a Mk1.

Probably a bit under half of the Mk 1's were delivered with twin Lehman's. A lot of people felt the boat was underpowered with just 240HP in total. So I picked the middle ground, ending up with 402HP in total. Was that a good decision? Well, it was good in that I did not need to replace gearbox or props. I think Larry's high quote for his KK42 desktop study did include a gearbox, and it is not an insignificant cost.

Reality is that with 402Hp I can't get over the hump: I top out at 11kn now. I'm OK with that as I generally dont want to pay for the high fuel burn. But, I can achieve 10kn with 215HP. And 9kn is only using about 125HP. So, I would think the Lehman's are actually a good fit for displacement speeds in a Mk1.

Were I doing it again I would probably choose the JD 4's. My middle ground is not a problem, but I could be traveling the same speed for a lower purchase price.

 

[Nomad Willy]

Repowering is a great place to be .......

Choices Choices Choices

Everything you want.

 

[Ski in NC]

The JD 4's are now supposed to be smoother than the 6's due to the wonders of CAD, modern manufacturing and balance shafts. Certainly the old rule of 'always choose the 6 for smoothness' is no longer a given.

CAD and modern manufacturing is not going to improve the roughness of a four. Sounds like marketing fluff.

There are two vibration modes on a four: Dead idle where there are only two fires per rev. Makes engine try to shake the boat at low revs. Usually an idle issue only.

Second is a high rpm "buzz". Technically described as a second order vibration, makes engine shake directly up and down twice per rev. This vibration is only noticeable at high revs (maybe 1600 or so, up) and can be canceled by the balance shafts the JD apparently has. So this mode should be a non-issue for those contemplating the JD 4045.

For trawler service, the idle shake is probably the biggest reason the four is avoided. It can be moderated with very good mounting design, but it cannot be isolated completely. Even my best design efforts with a four mounting have been only moderately successful isolating idle shake. Most just opt for a six. A six also has an idle shake, but since it hits three times per rev, you can idle it down lower and still be smooth. Sixes can idle down to around 600, a four even mounted well is lucky to go down below 750 before the shake gets too bad.

Fours can do the job, certainly. But the smoothness of a six to me is worth the extra cost.

There are good reasons most trawlers use a six of some flavor...

 

[Nomad Willy]

I think that's basically not true Ski. But it is true relative to what we have at our disposal.

Three and 4 cylinder engines on motorcycles and cars can be made with almost no vibration at all.

I had a BMW triple that was so smooth I occasionally found myself riding for 5 or10 miles at 60-70mph not in top gear. No vibration at idle either or anywhere else. They employed a flywheel running off a gear and of course slightly offset and interestingly counter rotating. The counter rotating has a very significant effect on torsional vibration.
In a boat engine an offset flywheel would be much closer to the center of rotation and the output shaft location would be lower ... another advantage.

My new 4cyl VW Jetta is also smooth. Much smoother than any 4cyl car I've ever driven before. I need to look at the tach to see if the engine is running while idling. I could go down the highway in a low gear turning several thousand rpm and it would be smooth enough to go miles in that mode.

Diesels have considerably more torsional vibration but the principals of vibration control applies equally to gasoline and Diesel engines .. as far as I know.

My new (9 years ago) Mitsubishi engine is smoother than the Perkins engine it replaced. But not much. There's no design features that I'm aware of that should make the Mitsubishi smoother. Same pre-combustion chamber that Perkins has had since the 60s. Same type of fuel injection.

The inclusion of balancers in the 4cyl Deere indicates balancers are effective in diesels. Other technology probably is too. So Ski I believe 3 and 4cyl engines can be as smooth as 6cyl engines. The manufacturers need to employ the technology before it will become a reality. Also I think engines that are used for small boats are far down the technology road. So it will be a time yet till smooth boat engines are offered. And when that happens perhaps rubber engine mounts won't be necessary. Nice thought.

But for now you're probably right ... 6cyl engines are smoother than fours. My engine could be made smoother than it is though w a heavier flywheel. Probably isn't available as many applications of the Mitsubishi 4SL2 are weight sensitive. In a FD trawler a light engine has little value. Wish a heavier flywheel was an option. I did choose a marineizer that included a steel exhaust manifold. Nice to be able to make options such as that.

 

[Ski in NC]

MB- we probably agree more than not. A few bits: A three actually has a less "harsh" vibration than a four, and in smaller engines the vibes are much easier to deal with. On the BMW bike, the counter rotating flywheel is part of the vibe cancellation strategy. Threes have a first order "waddle" or orbiting force, but being first order is usually not that objectionable, and is fixable with balancing shafts or the flywheel.

I too drive a tdi jetta (2001) and it does not have balance shafts. The new ones (2009+????) do have balance shafts, and are quieter at higher revs. Mine has a drone (not bad, but as an engine engineer I detect it) around 2100rpm. The new ones with balance shafts, that vibe is gone. Also, the smoothness at idle is in part due to rpm being higher (800 for new tdi, 900 for my old one), and due to an excellent job by the Germans designing the mounts. I think I can design decent boat engine mounts, but I don't have the resources those crafty Germans have!!

But the bottom line is the 4cyl large displacement engine has a low rpm shake that is not easy to isolate from the boat.

Diesels also have more idle shake than gassers, as the higher compression ratio makes more of a "bump" as piston comes up to tdc to fire. Not only has the diesel a higher CR, but a gasser when throttled the effective CR is much less than that calculated. On a gasser, compression at idle does not begin until piston is past half way up, as intake air is choked by the throttle. That makes it smoother.

 

[Insequent]

For trawler service, the idle shake is probably the biggest reason the four is avoided. It can be moderated with very good mounting design, but it cannot be isolated completely. Even my best design efforts with a four mounting have been only moderately successful isolating idle shake. Most just opt for a six. A six also has an idle shake, but since it hits three times per rev, you can idle it down lower and still be smooth. Sixes can idle down to around 600, a four even mounted well is lucky to go down below 750 before the shake gets too bad.

I ought to have asked the JD dealer for some hard data to support his smoothness claim, and will try to remember to do that at the next boat show. Interestingly though in view of Ski's comments above, the JD 4045 has a listed 600 rpm idle speed for the Tier 3 engine.

 

[FF]

Since a well managed boat will spend as little time at idle as it can, the real question is how silently and smoothly the vessel is at normal cruise.

Most modern engines do fine , even at the high load , lower RPM required for best fuel burn.

Modern diesels will not warm up, or stay at operating temps at idle anyway , so most folks will run 700-900rpm on cold start for a min , before getting underway.

The engine has to be just warm enough not to stall when shifted into gear.

 

[Nomad Willy]

Ski,
Good post your #27.
I drove a VW diesel when our Golf was in the shop. All day loaner. A 2012 Jetta automatic. It was an amazing car and I loved driving it. The amount of power in town was unbelievable for a diesel.

I have a TSI gas engined VW w manual gears. Diesel is fine in my boat but I prefer gas in a car. My TSI is a brand new engine. A 1.8 turbo but nothing is the same beyond that. There is no external exhaust manifold ... it's built into the aluminum head and exhaust goes directly into the aluminum turbo. Unlike the old 1.8T this boy has some T lag. But no premium fuel required. The power is stunning ... especially in 2nd gear. Millage is listed at 36 hwy. The new TDI is 42.

Two TDI engines would power a 36GB don't you think? That would save over a ton (literally) of weight. Our marine engines are WAY behind the tech curve. Can you imagine how smooth and quiet a TDI 36GB would be at 10 knots?