ford lehman

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chisholmdn

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Joined
Jul 10, 2014
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1
Location
usa
how many hours can one expect from the ford? am looking at a 34' with 5500 hrs. do I need to worry about remaining engine hours?
 
With PROPER maintenance 10,000 - 15,000 hours or more can be seen on a Lehman.

Hell, they are so bullet proof with spotty maintenance you can still get thousands of hours out of them.
 
This has been asked several times that I have seen. The general answer is that it all depends on how it was taken care of. I have seen several people say get an oil analysis, have a detailed engine inspection (separate from a survey), and a host of other things. I think all of this information should be taken in and then put together for an overall picture.
I.E. an engine oil analysis is fine but much more valuable as an ongoing thing to see trends than a snapshot. If you don't know how long the oil was in and it comes back with no problems noted- how do you know it wasn't changed 20 hours ago?
Engine surveys are fine but again, short of pulling heads and getting in to measure tolerances tough to say how much is left in them.
I bought my boat (FL120) with 5,200 hours on it and the engine and tranny are possibly the best parts! ha ha They have worked with no problems at all. I took the Bob Smith class and did the things he said to do and have very high confidence with my motor.
Run the boat, take it up to WOT and it should get somewhere in the 2450-2600 range. Do that slowly and only after running it for awhile and with the brokers permission as if it is not in great shape you don't want to be on the hook for "breaking my boat"! Look for smoke and noises and such. Have someone that knows motors -diesel motors- with you. Experience is a big plus here.
Bob Smith said these motors really come into their own at around 5,000 hours. They should last over 15K before a rebuild. That was his words. He seemed pretty knowledgeable about them.
These are only my opinions and I'm sure others will have different ones. I think many people believe the FL120 is outdated and therefore obsolete. I find it super easy to work on and after taking the class, have no reservations about maintaining it at all.

Jeff
 
Greetings,
Welcome aboard. Mr. c. Well, If you're 15 years old and you plan on cruising over 200 hours a year for the next 50 years I'd say with proper maintenance, as mentioned by others, you'll be looking at replacing that engine somewhere around the year 2065. Let me know how it turns out please.
 
5200 hrs and original is probably a reasonable indication it's been taken care of. Having said that, it is probably 40 years old so bargain hard with the seller. I hate to say it, but it's a buyer's market.

If you do buy it, and there are no records, plan to change the oil and filter, the on engine fuel filters (at least), set the valves, check the integrity of the fuel injection system and particularly the return lines (all at the same time as the valve work), replace the raw water impeller, clean or replace the heat exchangers, buy a spare lift pump, change the oil in the Simms pump, check all the belts and burp the coolant bleeder. The transmission will love you for an oil change too! Look carefully at the exhaust and hoses...

I'll think of other things. The only difficult bit is the valves, otherwise you can do it all yourself.

Lehmans smoke and put fuel in the water at startup, this is normal but might be a bargaining chip. Excess fuel means it's time to repair or replace the injectors.

Have fun!
 
Here is a very simplified version of a post I made a year or so ago on surveying a marine diesel engine. If it passes all of the following it is probably good for another 5,000 hours. But without doing something like this, there is no way of knowing. Anything said above is just generalities.

The Lehman and most normally aspirated diesel engines can often go 10,000 hours if used properly and taken care of properly. The following is an objective test of how well that was done in the last 5,000 hours.

1. Starts from cold within a few seconds of cranking. Probably the single most important test.

2. Smoke clears in a few minutes to just a light wisp.

3. Reaches rated wot rpm in gear. Does not overheat.

4. At cruising rpm open the oil filler cap and feel for blowby pulses. No pulses is good. Significant pulses indicate worn rings.

5. Oil pressure ok- 30+ psi at cruise.

6. Back at the dock, no fluid leaks. Fluid levels the same as before you left dock.

7. Open coolant fill cap after it cools down at idle. Look for bubbles. Bubbles is an indication of blown head gasket.

A prospective buyer can do all of the above himself or he can hire an engine surveyor and use this as a checklist of things to look for.

David
 
My pair have 4700 and are doing well. If well cared for, 5500 hours should not be a concern, just a bargaining point. However, mine have been cared for.

The engine could be in wonderful internal condition, but if a cooling impeller, heat exchanger, or cooling hose fails while you are motoring along at 2300 rpm the engine could be severely and expensively damaged. Those 15,000 hour lifespans depend on the other stuff being replaced before it fails.

American Diesel at 804-435-3107 is a prime source for parts and information. Bob Smith is the owner and presents the Trawlerfest training seminar that Jeff mentions and that several on this forum have taken. He even answers questions over the phone, he's great to talk with.
 
Must agree with all above comments. Barring something stupid the Lehman will outlive you and me.
 
Nicely run in, really. They are simple understressed proven long lived beasts of burden. 120hp out of 6.2L? Plenty of modern cars exceed that out of 2L or less, my 2.2L diesel Peugeot puts out 204hp(150kw and 450Nm of torque), no sweat. But, look after them and defer to age.
 
One small quibble with your post, DJ, is that Lehmans will smoke right up until they reach operating temperature, which it's likely to do at the dock unless it is run up in gear. Well, maybe 2 quibbles, if you pull the cap off while running, it really doesn't tell you all that much: Lehmans are agricultural engines and they are mounted at an angle. After 40 years or so, people still have mis-marked dipsticks and tend to put into much oil. If the rear journal is submerged it will thrash the oil pretty good and you will get more blow by than you would if you put the correct amount of oil in her. Besides, Cummins engines are renowned for their blowby. My crankcase vent exits right next to my exhaust and it puffs quite a lot.

I know, we were talking Lehmans and you slipped in generic...
 
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