Need Advice - Lehman - Rebuild or Replace?

Forum Colleagues,
Need advice - I have a 1976 Marine Trader 40' dual cabin / dual engine. The starboard engine's (Lehman 120) crankshaft broke recently and the diesel shop has told me they want $21K to do a complete removal/rebuild, or $17K to replace. Is this a fair price? I was looking online at the price of rebuilt engines and they are less than $10K so I was thinking of buying one and having the local boatyard put it in... and selling the old carcass for parts. Has anyone done something like this? I've attached two pictures of the engines. Again, any advice on rebuilding or replacing would be greatly appreciated. Best regards, Scott B.

FlyNavy,

Been there done that. VP31 SanDeigo. 1963.

See this thread;

http://www.trawlerforum.com/forums/s6/lehman-replacement-10072.html

Could the 17K quote be the same 10K priced engine, plus a margin, plus freight, plus R & R?
Checked the thread Eric mentions, it`s about using an entirely different engine. Not workable as you have twins (the Lehman Brothers, as Daddyo says), plus staying with the same saves a heap of other changes.

We did a Lehman 120 rebuild about four years ago, cost about $23,500. Of that about $3,500 was for removal and replacement. Given that things tend to be a bit cheaper, on just about everything, your side of the pond it seems about par for course.

If you go down the rebuild route check exactly what is covered on the rebuild,specifically injectors and heater exchange.

With the engine out give some thought to getting the transmission overhauled, pretty easy to do with the engine out.

Good luck.

why the engines are out you may want to give a real hard look at your fuel tanks

What would be the possiblility of using your good engine and converting your boat to a single? Lots of 40s were singles.


Just trying to think outside the box.

Nobody has posted it yet so I would suggest calls to American Diesel, 804-435-3107, or Bomac Marine,954-766-2625, and discuss options with them.

I'd be pretty cautious of a $10K rebuild, but if the rest of the engine is good and undamaged just replacing the crank might be an option if one can be found, and leave the cylinder and head work for another time. Have the shop pull the engine, turn it upside down, do the bottom end (crank and bearings), put it back in.

Hours on the existing block, yearly hours of use, and how long you plan on using the boat all affect that choice.

Are you sure the crank shaft is broken? Or is that an assumption? That was one of the things we were told about our Ford Lehman 120 by a Deisel mechanic, before we found out it was the damper plate between the tranny and engine.

I can't imagine anybody after reading the thread referred to in post #2 would rebuild an old Lehman.

Selling the still functioning Lehman, repowering w two smaller engines or as a single w a new engine seems to be the best thing to do. Repowering gives the option of selection whatever one wants for power so that the best loading of the engine at normal cruise can be fairly accurately achieved.

Having said that the previous suggested option of finding a crankshaft, installing same and running as before would be fine ..... If the engine or engines are/were in good shape. But I'd be strongly compelled to repower.

"I can't imagine anybody after reading the thread referred to in post #2 would rebuild an old Lehman"

What can I say? Some of us like the FL120. Mine has run for 35 years and still purrs like a kitten. Sometimes it comes down to a matter of taste. I don't think you can fault them for reliability. I do think it is too big a motor for most of the boats it was installed in, including mine. It should have had the FL 80.

READY2GO said:

...Some of us like the FL120. Mine has run for 35 years and still purrs like a kitten. Sometimes it comes down to a matter of taste. I don't think you can fault them for reliability.....

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Repowering with a different engine makes no sense. I`m with you Ready2Go, and the OP. He has twins. 2 different engines is possible, anyone really want that? So, rebuild one engine, or dump both, even the good one, spend up on 2 new engines, new wiring, instruments, mountings, gearboxes,exhaust mods, shaft mods, etc etc. Isn`t that what`s called "throwing the baby out with the bathwater"?
Of course it`s an engine rebuild/repair, not a repower. Switching to a single is equally impractical, think of the modifications to do that. It`s a question of the best economical way to repair/ replace the sick engine. It`s the KISS principle.

This is one of those situations where you have to be careful not to put 40k of repairs into a 40k boat.

"That was one of the things we were told about our Ford Lehman 120 by a Diesel mechanic, before we found out it was the damper plate between the tranny and engine.}

You bet,,, bad damper plate is about 1000 times more common than a broken crank shaft.

Well I see the OP hasn't been back to tell us it was a damper plate.

One in our Willard group suffered a broken crankshaft in his 4cyl Perkins and I've wondered ever since how much it had to do w the fact that the Perky was 35 yrs old. But old engines fail for many many reasons. I repowered my Willy when I decided to move to Alaska mostly because of the very remote places I knew I was going to go. I haven't been sorry now that we are back in Washington state but of course it would have been much cheaper to have kept the Perkins.

Umteen years ago a friend driving his dad's car fast said "if you want to go fast it's best to have a newer car". I'm in the process of up grading my cars and have been driving some much newer and even one new car. They are amazing. There are some ways that the old cars are more friendly and likable but over-all you just can't beat a new car. I could drive a 37 Plymouth every day if I so chose but if I drove a new car one month and the 37 the next I'd be very eager to get the new car back. You can live in a cave w a hairy old hag but if you ever come out of the cave and see the world you'll not want to go back.

It boils down to money. If you can repower or otherwise rebuild your boat the way you wish it to be then you need to address the question of "is it better to rework the old or buy a newer boat". And of course boats aren't exactly like cars either. If I had more money (even twice as much) I'd have another boat and I'll bet most of us here would do the same.

So if we can't afford to repower, and it seems most of us are probably there then the comments above that say "we love our old Lehman" have much more validity whether the old Lehman is lovable or not. Most of us are probably at the end of our financial rope just to acquire and basically maintain the boats that we have so a repower is like my dad suggesting I buy a new car when I was 17. But I agree that the OP probably just needs a damper plate.

READY2GO said:

This is one of those situations where you have to be careful not to put 40k of repairs into a 40k boat.

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Good advice but not good all the time. I did that but w a little lower numbers and it worked for me but it was w a rather unusual boat and I bought her a bit low. I repowered and retanked her and lots of other things and after it was all done I have a boat w all the stuff I like. Literally, mostly a custom boat.

But if I had bought an old 34' CHB that needed much work I'd have been better off selling the CHB and buying another similar boat that already had been largely rebuilt. A broker once told me buying a boat that had been bought and sold 3 or 4 times by owners that pumped a lot of money into the boat w their favorite things was the way to buy. But for reasons I talked about in post #15 that would be a very rare boat. Most trawlers are probably in the opposite category having been owned by people that really couldn't afford them and just squeaked by. So the brokers advice would be hard to follow.

So READYTOGO you are basically right in that I couldn't sell Willy for what I've got into her. But if I was given all my money back to buy a boat all over again I'd probably have a very hard time finding a better boat for me. So it worked for me but went against your good basic rule.

Eric I understand what you are saying and that it worked for you. By the way, I don't follow my own rules or common sense sometimes myself. My current boat we bought for $20k. I have allready put another 12K in parts and upgrades, and will put another 20K before I have her exactly the way I want so I can persue my dreams and goals. So I will have about 52K and literaly thousands of hours into a boat that I would be hard pressed to get 45K out of. But, she will be exactly what I want and I will know every inch of her.

Boating: expensive. Having exactly what you want: priceless.

Boating: expensive. Having exactly what you want: priceless.

Getting what you want is easy , just $$$$ and time,

knowing what works best for what you want to do, is the hard part.

Thanks Bruce - Eric is probably correct on what's going into the price - I am leaning toward replacement. SB

Thanks - got another recommendation to call American Diesel, which I will do next week and let everyone know how that goes. SB

Eric,
Thanks for the replies and advice. Am leaning toward replacement - going to call American Diesel next week and let the Forum know what I decide. BTW, did VP-31 in 1992 on my way to Dept. Head tour with VP-46 out of Moffett Field. Good times. SB

FlyNavy,
Since you've got twins your'e almost stuck w those Lehmans unless you replace them both w different engines. If it were me and I liked the boat a lot I'd get a new Iveco for $16K or Cummins remanufactured. I can't believe what they want for rebuilt Lehmans.

If you did the necessary carpentry to reconfigure and the #2 Lehman is excellent perhaps that would be a cost effective option.

FlyNavy,
We did P-5Ms, P-2Vs and HU-16s (Albatross) in the early 60s.

What about swapping out the Lehman engines for a couple of Yanmar 55's for example? This would reduce the cost per engine....approximately 10,000 per motor plus labour and other bits and pieces. It would likely free up some engine room space and would retain all of the benefits of twins, but with new motors rather than one old and one rebuild. I replaced a 65 volvo md30a with the 4jh4ae 55hp Yanmar in my motorsailer (did the work myself) and was likely into it for 15,000 with me doing all of the labour. This included a total redo on the exhaust system with waterlift muffler and some custom mounts for the new motor. It also included a new larger/thicker propshaft, pss dripless seal and a custom coupling for same. If it was me i would go with less power/size and replace both. I would think this would still provide you with plenty of power?

I agree w jarod but there are lots of engines out there way less expensive than the Yanmar. That Yanmar IS excellent though however expensive. I've heard nothing but good about the JH Yannies.

Two years ago there was a 36 GB on Yachtworld w 55hp Yanmars. I watched it to see if the engines made it hard to sell. Seemed to not be a problem as I think it sold almost right away.

The 54hp Isuzu would do just as well and save one 4 or $5000.

I agree with Eric the Yanmar is one of many options. My only caution would be to go with a manufacturer that has been in the marine biz for a while and even then there is no guarantee of reasonable parts costs or availability in future. I selected Yanmar purely on their history in the marine engine business and there proven record of parts availability. The Volvo the Yanmar replaced was a headache of epic proportions....not that it wasn't a good motor (it was), but a new heat exchanger was quoted at $5,000 if it was even available which it turned out it wasn't. The Volvo eventually gave up the ghost with water in the oil, but there was never a question of a rebuild with that motor. I knew as soon as its life ended I was going to replace with new. The headaches associated with parts availability and cost really turned me off, but i digress.

manyboats said:

FlyNavy,
We did P-5Ms, P-2Vs and HU-16s (Albatross) in the early 60s.

Click to expand...

My Dad flew in the same. Ever at Moffett, Iwakuni, Hawaii, Maine?

I did P-3's myself from 1981 through 1990.

To me the question of engine replacement would be whow easy it is to gat a bellhousing to keep the origional tranny , if that is planned. I would upgrade .

If not an International DD 360 or 466 and a rebuilt twin disc would be my first choice for low buck engine swop.

A low mileage engine $3-4,000 each the tranny about $1500 , the exhaust either dry or the std truck manifold with a jacket will do fine.

Flynavy, PM sent.

Since we're talking about Lehman diesel, I thought I would share some info and pictures. We just put our engine back together getting ready to run it tomorrow. We stripped everything off and painted the block, starter, head, manifold, tranny, etc. rebuilt the tranny( longer job than thought, but will post a YouTube on that one. Stay tuned.) injectors cleaned and a few other items just short of pulling block and rebuilding. Even at that it was a lot of work. Probably 12 working days. Much of that was prepping for paint.

Here is a shot of the new flywheel damper plate installed. The springs that broke seized the engine just as if, crank broke or other major problem.