High hour Lehmans

So I hear that Lehmans are very capable of reaching 10-15 thousand hours before a rebuild if they are well maintained. I would like to hear from members that have high hours on their Lehmans and what type of repairs they have made other than normal maintenance.

Mine just passed 2600 hrs on a rebuild.
repaired alternator and starter (but they could have been used on former engine, though a slight coolant leak is what did in the starter I think)
2 injector pipes have failed.
injectors replaced
oil coolers replaced
heat exchanger hand cleaned.
Various hoses replaced
alternator belt replaced
alternator upgrade this year and bracket bolt broke requiring drilling out
Hregular replacement of water pump impellers

At about 2800 hr this summer

Will pull head to correct a possible head gasket issue, check cylinders.
Possibly rebuild injector pump.

Mine just passed 2600 hrs on a rebuild.
repaired alternator and starter (but they could have been used on former engine, though a slight coolant leak is what did in the starter I think)
2 injector pipes have failed.
injectors replaced
oil coolers replaced
heat exchanger hand cleaned.
Various hoses replaced
alternator belt replaced
alternator upgrade this year and bracket bolt broke requiring drilling out
Hregular replacement of water pump impellers

At about 2800 hr this summer

Good info. How many hours before the rebuild.

Have no idea....previous owner with not a clue.

We rebuilt our FL SP135 last fall with 8400 hours. We had the engine out to replace the fuel tanks. That was the only reason. We added about 1 qt of oil every 200 hours. Oil analysis came back perfect.

I am at about 4400 hours on the original.

Purchased my FL SP135 with 5197 hours very detailed log back to 3853 hours no known rebuild. Currently 6092 hours, no engine repairs needed. Only new parts Alternator and starter and scheduled maintenance. No change in performance.

I would think a high hour engine that had'nt overheated and that has good compression on all cylinders should be a good indication that it received good maintenance.

How frequent is the rear cylinder overheating problem? Must not be a frequent occurance as there's not much said about it. But it does come up. Perhaps it happens when an engine sits for long periods.

Bleeding the water jacket as per the owner's manual is very important to prevent overheating.

Nomad Willy said:

...How frequent is the rear cylinder overheating problem? Must not be a frequent occurance as there's not much said about it. But it does come up. Perhaps it happens when an engine sits for long periods.

Click to expand...

The issue is/was only with the Dover FL 120s not the Dorset FL 135s.

About 5000hrs on my two 135's. No issues. Other than normal maintenance items, both Velvet Drives overhauled at 4500-4800 hrs, 1 starter and 1 alternator rebuild. Oil analysis on both engines has been coming back perfect.

Ken

psneeld said:

..Will pull head to correct a possible head gasket issue, check cylinders..

Click to expand...

You could try a re-torque of the head studs. We did,I think it helped my old 120s. Mechanic was nervous and researched it first,and torqued to the lower of the range. But, a no no for 135s, according to a previous thread.

BruceK said:

You could try a re-torque of the head studs. We did,I think it helped my old 120s. Mechanic was nervous and researched it first,and torqued to the lower of the range. But, a no no for 135s, according to a previous thread.

Click to expand...

Thanks....will debate whether to try that or just bite the bullet when moored for 6 months till next long trip.

i always understand Lehmans overhaul point is around 8000 hours under good maintenance...

Interesting Bruce, I understood that the 135s needed retorqueing at some hourly interval but the 120s didn't? I actually did retorque my 120 cylinder head before I readjusted the valves. My understanding is that stretch bolts do not need retorqueing, they would need to be replaced. I also did not think that Lehmans had stretch bolts...?

My advice to high-time Lehman owners is to follow the owner's manual, complete all of the required maintenance requirements and run the bag off them. They will run fine for a long time and then they blow, although it's rare, even with an overheat (fatal to a Lehman) that it will quit dead and leave you stranded.

Xsbank said:

...I understood that the 135s needed retorqueing at some hourly interval but the 120s didn't?...

Click to expand...

Do you have any sold info? We have about 100 hours on our rebuild and we were told specifically not to re-torque our 135.

Xsbank said:

Interesting Bruce, I understood that the 135s needed retorqueing at some hourly interval but the 120s didn't? I actually did retorque my 120 cylinder head before I readjusted the valves. My understanding is that stretch bolts do not need retorqueing, they would need to be replaced. I also did not think that Lehmans had stretch bolts...?....
.

Click to expand...

My nervous mechanic found an instruction to retorque a 120 before valve adjusting, that made us comfortable doing it.
I`m sure there is a thread on this which said never retorque a 135. I`m guessing a stud could snap,that`s no fun. But if you had the head off a 135 you have to retorque. Surely you don`t need to change the studs if you pull a 135 head? Maybe you do.

Sorry Larry and Bruce, I do not have access to my 120 owner's manual but the GB site does, you could get downloads from them for free.

Larry M said:

We have about 100 hours on our rebuild and we were told specifically not to re-torque our 135.

Click to expand...

See post 17 Larry. Don`t do it.

I have heard it both ways...torque...don't torque.

There are threads that go back with good advice from SkiNC and RickB.

If you don't know what kinds of bolts were used...you just have to roll the dice.

Larry, Bomac should be able to tell you for sure.

The consensus seems to be if you don't know what kind of bolts you have, and no problems, don't retorque. If you do have some kind of problem...like I might...you have some options.

1. Retorque
2. Pull bolts one by one and replace with a known quantity,
3. Pull the whole head, inspect everything, new gasket and used known quantity bolts.

Even American Diesel is a bit back and forth on the subject through the years.

Larry M said:

Do you have any sold info? We have about 100 hours on our rebuild and we were told specifically not to re-torque our 135.

Click to expand...

My 135 owners manual is very specific about NOT retorqing the head bolts.

This is a direct copy from the manual:

DUE TO REVISED HEAD GASKET, HEAD GASKET AND HEAD BOLT DESIGN RETORQUING OF CYLINDER HEAD IS NOT REQUIRED. AND MUST NOT BE ATTEMPTED

Seems pretty clear to me.

Also, the generic Ford 2720 Range 4 & 6 Cylinder Diesel engine manual which covers the 2722, 2723, 2725, 2726t and 2628t engines also states (on page 18) "the cylinder head retaining bolts must not be retorqued"

Ken

Larry...DON'T GUESS!

You just got the engine...a phone call is all but certain.

I coulda had a Perkins!

FlyWright said:

I coulda had a Perkins!

Click to expand...

And a manicooler!

Four years ago I was talking to Bob Smith and asked him pointedly the specific question, all of this ridiculous anecdotal dribble comes from (how long does a Lehman last.... 10,000 hours ....15,000 hours....who do you know that has one those with those hours?......) Bob, how long should a well maintained Lehman last before a rebuild?

Bob: There is one with 85,000 and a second with 87,000 hours that I know of that haven't been rebuilt yet so I really can only say 87,000 hrs plus.

Both are connected to agricultural pumps and are running 24/7.

BTW, my Lehmans have 6,500 hours and I would trust them crossing the pond in a minute.

Well, I got something right, I said to read the manual!

As engines age and rack up hours, the things that tend to bite you are water pumps, torsional couplers, alternators, starters, coolers, gear oil seals, rotted exhaust, etc. Rare for the base engine itself to fail in a mission-ending manner.

I'd have no issues trusting a FL with 10k hours. No different than the trust level on one with 5k hours. Get to 20k hrs in a boat, and it might get some extra scrutiny, but if it checks out well, no issues.

10k hrs in a road vehicle at an average of 40mph is 400,000m. Road tractors reach this easily before engine work. Many make 1,000,000m. By then the vehicle is ragged out, even if engine is still a trooper. I suspect a boat with 20k hrs on it may be a bit ragged out, too.

Only 8000-odd hours in a year, to put things in perspective.

This is interesting. Relating it to cars is even more interesting.

One can find cars w 290kmi on the meter easily .. meaning there are quite a few on CL. I have one myself. I put a clutch in it and new tires. Struts, exhaust, heater, trans, power windows, and almost everything else is fine to ok. Turning hard left shows lots of wear on the steering rack.

Here's the thing that makes me wonder. Hardly ever see a car w over 300kmi. The cars seem to fall off a cliff at 300kmi. Admitedly many sellers wo'nt post milage over 300k as they surely must think it's like say'in "this car is about to fall flat on it's face". But there dos'nt seem to be a "cliff" for these boat engines.

Wonder what kills the car engines?

With the boat engines the killer could be cold starts. The pump engines seem to go on forever but many boat engines do'nt last 5k. Car engines get used regularly .. most all of them. I've been trying to find another little Nissan Stanza for a few years w very low miles but still have'nt. I probably have found one w 88k but I did'nt act fast enough and it sold fast for $3000.
Could be related to the boat engines being diesel but I think not. I'm not talking about how long they last just how abruptly they die at a specific # of hours or miles.

Our SP 135 has 4000 hours and running the original alternator and belt (28 years). I run
the belt just a tad loose and it reduces the wear in the belt and the alternator bearings and still does a great job of charging the batteries. I will probably replace the belt this spring.

Oil Deckhand,
Same w me re my seawater pump.