For Sale: Ford Lehmans

[MV_Fevik]

Hey All-

I will be re-powering my Grand Banks 49 this spring with ReCon Cummins 6BTs. Couple reasons for the repower.
1) IMO I am slightly underpowered. Fully loaded I am probably pushing 80K lbs and my Lehmans don't give me any reserve power.
2) I plan on cruising south next year and would feel much more comfortable with new engines.

I can say in all honesty if I did not intend to so some serious offshore cruising i would not be repowering. Both engines run strong.

One engine is the original Lehman 120hp, and the other was replaced with an American Diesel 135hp. The replacement was done before i owned the boat and i don't have the full story there.

Anyway, replacement 135hp runs like new. There is a little diesel fuel leakage from the injection pump, which once running at full temp just evaporates away.

The original 120hp has a slight knock to it. Nothing crazy but you can hear it.

So i would love to find a home for these engines. I have no idea what they are worth, if anything. Once they are out of the boat i'd be happy to assist in getting them shipped out. I'm in the San Francisco area.

If you are interested let me know what you have in mind as worth... and if anyone wants to comment on what the engines are worth that would be great. No offence taken on what you think. And again they won't be ready until probably June.

**transmission go too... Borg Warner**

 

[catalinajack]

That knock you have in the 120 may be indicative of the need to retorque the heads and then adjusting the valves. A FL120 requires both at no more every than 1,000 hours. As far as being underpowered, 80,000 lbs is a lot but is being "slightly" under-powered worth the expense of removing perfectly good engines? Apparently, it is to you. In any case, how have you determined that you are underpowered? Those Lehmans should reach about 2,500 RPM, the FL135 maybe 2,600 RPM, at wide open throttle. If you can get there with your engines, you are not underpowered. That assumes your GB is a full displacement vessel.

Others, please correct me if I am off base here. Also, prop pitch and diameter is part of the equation.

My boat weighs 56,000#. It is not underpowered with its twin FL120s. I cruise at 8.5 MPH at 1,650 RPM.

 

[Choices]

I don't see a 135 that looks like mine...

 

[slowgoesit]

Engine hours on each?

 

[READY]

I have original lehmans in my 1976 Hatt 48 LRC. Both run solid. I cannot yet assign a value i would pay to have spares but I might be interested. Could load them in my pickup and bring to San Diego. Let's talk as you get closer. Please post age and hours and snap more photos.

 

[MV_Fevik]

Hours

120hp - 3719, 135hp 2319.

By the way I agree that I am only slightly underpowered... By my amateur armchair calculations I need about 180hp total (90hp each engine) to get to hull speed... However i want to feel comfortable pulling that at contentious duty. Much of my cruising will likely be single handed and south of the boarder... the expense is worth it to me.

Currently i cruise at 1800rpm and get almost 8knts there... Burning about 5 gals an hour (100hp used). I can't remember the last time i pushed up to WOT but that injection pump leakage opened up last time i did.

I will come back to this thread when i get closer and contact anyone who shows interest.

 

[catalinajack]

120hp - 3719, 135hp 2319.

By the way I agree that I am only slightly underpowered... By my amateur armchair calculations I need about 180hp total (90hp each engine) to get to hull speed... However i want to feel comfortable pulling that at contentious duty. Much of my cruising will likely be single handed and south of the boarder... the expense is worth it to me.

Currently i cruise at 1800rpm and get almost 8knts there... Burning about 5 gals an hour (100hp used). I can't remember the last time i pushed up to WOT but that injection pump leakage opened up last time i did.

I will come back to this thread when i get closer and contact anyone who shows interest.

My goodness, those engines are still in their infancy! They are just broken in. And good for another 15,000 hours if properly taken care of.. You get 8 knots at 1,800 RPM? I'd say that is damn good. Cummins experts comment here but my guess is that the 6bt's won't deliver any better than the Lehmans.

 

[timb]

I don't see a 135 that looks like mine...

the one with with the black oil fill is a 135 .I have one like it.

do you know the transmission ratios ?

is the 135 trans output left hand rotation .

 

[MV_Fevik]

I stand corrected...

What I thought was a 135hp is actually a 139hp...

I ran her hard today and came up with some numbers... I was dealing with a lot of current so unfortunately my speed calcs we're averages after running a few different directions.

WOT was better than i expected.
120hp = 2600, 139hp = 2700+
I was worried that the injectors would start gushing diesel but all was fine. I did start to smell something cooking so i didn't run WOT very long. A few minutes. And only one direction so that speed reading is pretty useless.

@2300 9+kts... Hull speed should be about 9.4kts so this is pretty much there. I could tell by my wake i had to be close to hull speed. Just didn't have time to find slack water..

My normal cruise is 1800 @ 7.8knts.

Question for catlinajack as sounds like you know your Lehmans... @2300 I'm probably using 75% of my engine rated HP. Too me that seems a little much for cruising days at a time. Just curious your (or anyone else's) thoughts on that.

Oh and there is one other issue with the 120hp.. It "makes" oil. Meaning diesel is finding its way into the oil, diluting it over time. I've tried to address the issue by adding copper washers on the injector connectors. That seems to have helped, but it sill happens a bit.

Like I indicated in my original post... if i was keeping the boat for coastal cruising in CA I wouldn't even consider repowering. Way too much money for very little gain. And I wouldn't mind pushing the engines form time to time.

 

[MV_Fevik]

yes 99.9% sure the 139hp, which is starboard, is left hand rotation. Of course now i am second guessing that so i will have to double check next time i am on board.

 

[BruceK]

My IG36 had L120s.I liked them.My Integrity 386 has Cummins 210s, no aftercooler. I like them too.

Is replacing the 120 with another 135/?139 an option? It resolves the identified condition issues(= confidence for long range cruising) and yields a little more power and rpm.

Switching engines/gearboxes, replacing exhausts, mounts, controls, instruments, fuel lines, filtration.....there`s more to changing engines than just"changing engines".

 

[catalinajack]

yes 99.9% sure the 139hp, which is starboard, is left hand rotation. Of course now i am second guessing that so i will have to double check next time i am on board.

What you have there is an American Diesel 6N140, the last iteration of the Lehman diesels, I believe. If you call Brian Smith at American Diesel in Kilmarnock, VA he can confirm that for you. Be prepared with the numbers on the build plate which should be on your valve cover. The 6N140 is not as common as the 120s and 135s but, I'm my opinion, the marinization setup is better thought out.

"Is replacing the 120 with another 135/?139 an option? It resolves the identified condition issues(= confidence for long range cruising) and yields a little more power and rpm."

Sure, you could do this but for a little more power? You would never notice the difference. Confidence in long-range cruising? Both are considered to be equally-reliable engines so you would gaining nothing but a few horsepower. Unless you have deep pockets, your boat dollars are better spent on something else.

"Oh and there is one other issue with the 120hp.. It "makes" oil. Meaning diesel is finding its way into the oil, diluting it over time. I've tried to address the issue by adding copper washers on the injector connectors. That seems to have helped, but it sill happens a bit."

Making oil, now that is a problem if you are talking about the lube oil in your sump. However, if you are talking about the oil in the injection pump, that is normal and is maintenance item. Bob Smith, the American Diesel guy, used to recommend, as it says in the FL 120 manuals, to change the oil every 50 hours. Later, he recommended an interval of as many as 150 hours based on actual experience. I have two FL120s. I change my oil every 150 hours even though, at that interval, the number of ounces drained is no more than what had gone in, 16 ounces.

Back to your lube oil, diesel fuel in your sump is not good. It could be coming from a partially fractured diaphragm in your mechanical fuel pump, a fairly easy fix. Or, it might be coming from the fuel return pipe under the valve cover. Early in my ownership, I replaced the mechanical fuel pumps with an electric pump in order to eliminate any possible future diaphragm problem. I used a Walbro pump which is rated for 18,000 hours of continuous use. If one does this, the port in the block where the mechanical pump was fitted must be covered. A cover plate plate for a "big block" Chevy V8 is a perfect fit, an $8 item.

"Question for catlinajack as sounds like you know your Lehmans... @2300 I'm probably using 75% of my engine rated HP. Too me that seems a little much for cruising days at a time. Just curious your (or anyone else's) thoughts on that."

No one I have ever read about cruises at 2,300 RPM. At that speed you will be consuming gobs of fuel for very little increase in knots. You seem to be concerned with using that 75% of rated horsepower. For Lehmans this is not an issue. Most owners cruise at between 1,600 and 1,800 RPM. Eighteen hundred is a bit much for me. I cruise at 1,600, sometimes 1,650 if I want to pay the fuel price for a bit more speed. At 1,650, I get about 8.5 MPH on flat water, no current with my boat weighing 56,000#, a half load of fuel and water. My fuel tanks are 700, water is 300.

MV_Fevik, I have learned a lot about Lehmans by reading this forum for many years but I am nowhere near being an expert as some others here are on this board. Perhaps "Ski in NC" will respond to your questions. If he does, pay attention to what he says.

 

[Redhook98]

On my 49-ft MT, the difference between 1700 RPM and 2300 RPM (with twin Lehman 120s) is only 1 MPH, and 3-4 times more fuel used. At 1700, I am at 4 GPH, with the Gen running. Just posting for reference.

 

[MV_Fevik]

Thanks all, i apricate the comments.

 

[pyonemura]

Hi. We are definitely in the market for a replacement 135; a 140 will also work. Please keep us in mind. We're in Friday Harbor, San Jan Island, WA. My email is pyonemura@gmailcom. Thanks, Priscilla