Lehman 120 rebuild or replace in 2024?

[rustyScupper]

Hello friends,

Sadly, my beloved Ford Lehman (2715E) 120 in my single screw CHB 42' seized up last summer and disassembly inspection showed significant heat damage to the crankshaft and block. Miraculously I was able to source a different block and crankshaft, but the machine shop says the replacement crankshaft is also heat damaged and recommends sourcing a different crankshaft.

Cost-wise I would prefer to rebuild the Lehman 120 as they are great engines and would get another 10k hours out of it, but I'm not sure where I can find another crankshaft or if it's time to replace it with an engine I can get parts for?

Still figuring out options for LRC configuration with the new regulations for marine diesel engines, but have been looking at some possible replacement engines:
* Cummins 6BT 5.9 210 - have to replace shaft, screw, and trans
* Isuzu 6HK1X - great, but hard to find
* John Deere 6068/TFM50 (M1) - apparently great, but pricey
* FPT N67 150 - not much info
* BETA 85T - doesn't seem big enough
* Electrical conversion -- no, don't think I can do that

For the forum, anyone got a Lehman 120 crankshaft laying around or thoughts on a better long-term replacement?

Thanks!
Rusty....

 

[Comodave]

Have you contacted Brian at American Diesel? He may be able to help.

 

[rslifkin]

If the existing 120hp was adequate, one of the turbocharged JD4045 variants or a Cummins 4BT 150hp should be plenty of power and possibly cheaper than the 6 cylinder versions.

 

[Comodave]

But the cost of repowering with a different engine will be very steep, new transmission, motor mounts, exhaust etc. it will be cheaper to rebuild the Lehman because that is the only cost. Now if you want a more modern engine then go ahead and pay for it.

 

[rslifkin]

But the cost of repowering with a different engine will be very steep, new transmission, motor mounts, exhaust etc. it will be cheaper to rebuild the Lehman because that is the only cost. Now if you want a more modern engine then go ahead and pay for it.

Depending on the trans that's in there now and the bellhousing pattern it uses, if there's no big change to horsepower or RPM range, a new engine may be able to re-use the trans. Even then, there's definitely more work involved. But depending on the cost of rebuilding the Lehman vs obtaining a different engine and what can be DIY-ed, it may not be a huge difference.

 

[BruceK]

Seen this? https://www.trawlerforum.com/forums/s68/2-lehman-120-diesels-69957.html
Possibly sold and or geographically impossible, but worth a thought.

 

[psneeld]

Also think about Bomac Marine...believe they still sell rebuilt or will rebuild your Lehman.

They are in Northern Georgia.

Ford Lehman Engines Parts | Remanufacture | Service | Bomac Marine

I also chatted with a place up in Seattle that was a Lehman specialist. Unfortunately don't have those notes anymore with name and number. They may rebuild or have rebuilt ones. They helped me along with Bomac when American Diesel couldn't.

 

[Mambo42]

If you can't find them in the States I know a shop in the Netherlands that overhauls FL. Bought 2 x FL 27 15 e last year from them, are installed, work perfect.
Shipping cost should not be too steep from Europe to the US, so might be an option if you can't find anything. I paid 5000 euro a piece for them. That includes injectors, fuel pump and cylinder head. Everything else you will need to use from your old engine.

 

[rustyScupper]

Thanks for the notes back. Yes, rebuilding is definitely the cheaper option and I'll follow up on the parts leads. Yes, spoken to Brian at ADC quite a few times and super helpful resource as always. Sadly, he doesn't have a crankshaft.

 

[Dwk]

Used on ebay

Have a look at this on Ebay… item # 176154420234 listed as Ford Lehman 2715E…..could be a drop in replacement…..

 

[rgano]

May I ask what was the issue causing the overheat of your Lehman?

 

[STB]

I also chatted with a place up in Seattle that was a Lehman specialist. Unfortunately don't have those notes anymore with name and number. They may rebuild or have rebuilt ones. They helped me along with Bomac when American Diesel couldn't.

Perhaps that was Harbor Marine in Everett, WA?

Been a few years since I heard their name mentioned on forums, but they used to keep rebuilt 90 - 135hp Lehmans in stock and ready to ship and had quite a graveyard for used parts:

https://www.harbormarine.net/

 

[Nick F]

I had the same CHB and looked at repowering. I would have used the BETA 85T. I believe it has plenty of power and it is mechancal injection (no electronics). I would have preferred a naturally aspirated engine (no turbo), but this seems to be necessary to get the EPA rating without electronics.

 

[Larry M]

Harbor Maine, north of you in Everett, rebuilds and services FL120s.

https://www.harbormarine.net/services

I went through the replace vs rebuild numbers on a FL SP-135. The rebuild was less than 1/4 the replacement costs.

 

[jleonard]

Have you searched to find a shop that can regrind the crank?
That might be an option.

 

[Moonfish]

I also chatted with a place up in Seattle that was a Lehman specialist. Unfortunately don't have those notes anymore with name and number. They may rebuild or have rebuilt ones. They helped me along with Bomac when American Diesel couldn't.

I believe you are referring to Fred Warner?

https://www.fredwarner.net/category/engine-parts/?brand=ford-lehman

Don't see a crankshaft, but they may be able to help find one?

 

[SteveK]

May I ask what was the issue causing the overheat of your Lehman?

+1, but also the second engine the crank is overheated. How/why?
Lehmans have had scores of #6 overheat reported. How does that affect the crank?

Is this shop being overly careful to avoid a future warranty of the total rebuild by using a used crank comes to mind. Would a top end rebuild last another decade?

 

[Jeff F]

I had the same CHB and looked at repowering. I would have used the BETA 85T. I believe it has plenty of power and it is mechancal injection (no electronics). I would have preferred a naturally aspirated engine (no turbo), but this seems to be necessary to get the EPA rating without electronics.

I think that would be a great choice. Did you price them out?

 

[Nick F]

I think that would be a great choice. Did you price them out?

A few years back and I don't rememeber now, but seemed reasonable.

 

[Jeff F]

A few years back and I don't rememeber now, but seemed reasonable.

https://marinepowerengine.com/home/91-beta-marine-85t-marine-diesel-engine.html shows new ones in stock at $6,300. That seems very reasonable vs a rebuild. I know what I'd do ?

 

[rustyScupper]

May I ask what was the issue causing the overheat of your Lehman?

Mechanic confirmed there was oil in the pan, but that an oil pump or filter issue prevented oil flow to the crankshaft bearings. The resulting metal contact generated enough heat to score the journals and warp the #1, #2, #4 crankshaft bearing caps.

 

[rustyScupper]

Have you searched to find a shop that can regrind the crank?
That might be an option.

Thank you -- the machine shop confirmed that magnaflux testing of the replacement crankshaft I pulled from a 2714E engine shows heat stress and checkmarks. Can't grind those out apparently.

 

[rustyScupper]

Harbor Maine, north of you in Everett, rebuilds and services FL120s.

https://www.harbormarine.net/services

I went through the replace vs rebuild numbers on a FL SP-135. The rebuild was less than 1/4 the replacement costs.

Yes, I've spoken to them several times about getting a replacement FL engine. Overall recommendation from Harbor Marine was that these engines are too old to consider throwing more money at and suggested the Cummins 4bt as a better replacement.

 

[Insequent]

Yes, I've spoken to them several times about getting a replacement FL engine. Overall recommendation from Harbor Marine was that these engines are too old to consider throwing more money at and suggested the Cummins 4bt as a better replacement.

Well, the day had to come sooner or later for an honest engine rebuild specialist to put that out there. Good on them! It is likely that those examples with lesser damage will eke out many more years and hours of running. However I think we are on the cusp of needing to discount selling prices of boats with those old things in the ER. I certainly would. They are nearing the old Volvo or Cummins triple nickel point.

I had the latter, and although they started first pop, no smoke, reached WOT etc once I had them out of the boat to replace fuel tanks a re-power was logical. Transmission, shaft, props did not need to be changed but of course costs did still add up. Now 12 years on I remain convinced it was the right decision.

For the OP, re-power may be worth it if the boat is going to be kept for, say, another 10 years or so. Otherwise a running take-out can likely be sourced, if patient.

 

[Comodave]

Before you decide on a 4BT check out and see if they have vibration dampening or not. I used to run an old Navy launch that had a4 BT in it and it shook quite a bit. I generally love Cummins engines but not the 4BT so much. The John Deere 4045 is balanced I think. Do some research before you jump into an engine.

 

[rslifkin]

Before you decide on a 4BT check out and see if they have vibration dampening or not. I used to run an old Navy launch that had a4 BT in it and it shook quite a bit. I generally love Cummins engines but not the 4BT so much. The John Deere 4045 is balanced I think. Do some research before you jump into an engine.

That's a good point. The 4BTs I've seen are good engines, but not the smoothest running or quietest thing out there.

 

[Comodave]

That's a good point. The 4BTs I've seen are good engines, but not the smoothest running or quietest thing out there.

About 20 years ago I was looking at repowering a trawler with 4BTs. I spoke to Tony Athens about it and he recommended against them because the boat was fiberglass and he said the engines were not balanced. He said the glass boat wouldn’t absorb the vibrations as well as a wood boat. He recommended 6BTs because they were balanced. Don’t know about the 4BTs now because it has been so long but it is something to check before buying them.

 

[Antares]

There are currently 2 FL120s on ebay.

 

[Insequent]

Before you decide on a 4BT check out and see if they have vibration dampening or not. I used to run an old Navy launch that had a4 BT in it and it shook quite a bit. I generally love Cummins engines but not the 4BT so much. The John Deere 4045 is balanced I think. Do some research before you jump into an engine.

Yes, the JD 4045 is balanced, and done very well. I spoke to their folks at boat show some years ago and they were adamant that the 4045 ran more smoothly than the 6068 (which runs quite smoothly anyway)

 

[Mako]

I had the same CHB and looked at repowering. I would have used the BETA 85T. I believe it has plenty of power and it is mechancal injection (no electronics). I would have preferred a naturally aspirated engine (no turbo), but this seems to be necessary to get the EPA rating without electronics.

Depends on what speed you normally cruise, what max you wish to attain and how much reserve you really need. If the OP is a 6 knot canal cruiser then you could argue the engine is overpowered.