Ford Lehman 120 locked up

[JD]

Today while out on cruise my lehman 120 locked up. She was running fine but started to make some noise, so I dropped the rpm. She kept running for another 15-20 mins with the noise and then she stopped and would not crank.
QUOTE]

Back to the OP's first paragraph. This does not appear to be a fix it cheap problem - soluition. It was run to near or total destruction.

And where was the Temp gauge all of this time??

 

[bobofthenorth]

Back to the OP's first paragraph. This does not appear to be a fix it cheap problem - soluition. It was run to near or total destruction.

That paragraph was the basis for my comment that it was time to start looking for a reman unit. We're all just armchair mechanics here but - IMHO - any mechanic that pulled the head and told the OP he could rub some emery paper on the crank and bolt it back together is not a mechanic I would want working for me.

 

[BruceK]

Badu, there is a choice. 1) Full rebuild/reman, or 2) fix the obvious, hoping you cure the underlying cause. Weigh up the cost either way, factor in the possibility the second option may not be a fix.
You may be right it was a simple head gasket failure, complicated by not shutting down. Trouble is the engine went on to suffer major damage. Have you checked the mating surfaces of the head and block and for any other reason the gasket failed?
You decided not to shut down when issues arose, presumably the safe decision in the circumstances, and you might do the same if there is a next time, risking consequential damage. You need the engine as reliable as possible, peace of mind is a factor.

 

[FF]

What caused the original failure?

The usual cause is a lack of following Da Book.

Some engines require the head to be torqued after a number of hours.Was it done 20 years ago?

Antifreez is NOT FOREVER! , so old antifreez could have dissolved enough of the head gasket or sealant to cause a leak.

WAs the exhaust maintained properly , or did sea water fill the cylinder leaving salts behind?

"What did the temp gauge say is a good question."

The Murphy Gauge with alarm feature might have made the situation easy to notice.

A gauge or two is always better than a basket of new part to install.

And mechanical gauges work longer than their electric brothers.

"It was run to near or total destruction"

A bad bearing and a scratch or two on a crank is no where near total destruction.

A rod thru the side of the block , perhaps

On the repair I would install a new block water pump, as a precaution.

 

[Nomad Willy]

Tom I'm going to side w Bob of and Ksanders on this one. Looks like the head gasket was the problem so fix it and the damage that it caused and the OP is back where he started. With an old engine and old engines are less dependable and durable (unless completely rebuilt) and a good model expertly rebuilt is still questionable. We had one of our members on the Willard Boat Owners (WBO) forum suffer a broken crankshaft in Chatam Strait in Alaska. Boat is being repowered in Juneau now. Old is old but thereof a possibility that the crankshaft failed for a reason that may be applicable to a new crankshaft as well so one never knows but I'd put my money on new any day I have that money. If I were the OP I'd fix it properly and go boating.


Now I see FFs post and very strongly agree w him. Also I can say that I have one of those Murphy Alarms and it may have already saved more than an engine for us.

 

[River Cruiser]

Antifreeze in the oil will wipe out the bearings, a blown head gasket will allow that to happen. Overheating will weaken a head gasket, a low liner could also be a cause. I've never worked on a Lehman but most of the diesels I have rebuilt the liner height had to be set with shims to get the proper crush on the fire ring. While the heads off have a mechanic who knows what he is doing check the liners, that may help determine the cause. Here is a example:
http://www.foleyengines.com/resources/tech-tips/all-you-need-know-about-deutz-diesel-liners

Good luck

 

[JD]

never worked on a Lehman but most of the diesels I have rebuilt the liner height had to be set with shims to get the proper crush on the fire ring. While the heads off have a mechanic who knows what he is doing check the liners, that may help determine the cause. Here is a example:
All You Need to Know About Deutz Diesel Liners | Foley Engines

Good luck

This is true of gas engines that have liners as well. A big problem is that an over heat will cause a slight problem that then grows into a head gasket replacement. The replacement is done by a brother in law, friend or owner that knows not about liner engines and when they remove the head they do not break the head away from the block properly or secure the crank from rotating when the head is off the engine. One or the other if not both result in a lower seal going bad where the liner seals to the block. But of course this goes unnoticed. The new head gasket is installed and the engine will sooner or later over heat once again but his time because the liner seal leaked anti freeze into the oil. Game set and match.

 

[sunchaser]

when they remove the head they do not break the head away from the block properly or secure the crank from rotating when the head is off the engine. .

In BADU's post 46 the head was removed and the un-secured crank indeed spun freely when they released the bad bearing.

It will be interesting to see if we hear back from BADU after he has a few hours on his repaired engine.

Some years ago I had a total in-place rebuild on an engine that the PO had overheated. When I sold the vessel, the buyer after me wanted a complete description, BOM and discussion with the rebuild guys before he closed the deal.

 

[JD]

In BADU's post 46 the head was removed and the un-secured crank indeed spun freely when they released the bad bearing.

Well if they put the required lock downs on the liners they are OK. Most engines have a Special Tool XXX that bolts to the block and holds the liners in place. What happens when one spins the engine or just turns it ever so little is that some of the pistons put an up ward pressure on the line thus lifting it off of its sealing ring at the bottom. Some engines have a paper gasket as that seal ring and this upward motion is sometime enough to tear or seperate the gasket. Rubber o ring gaskets can roll over and twist. Either case if it occurs it does not raise it's ugly head for some time. The tear in the paper takes time for it to deteriorate. The rubber o ring sometime reseals but with the roll over still in place which will give way later. Usually much later than the paper gasket.

Also another problem that needs to be addressed is the protrusion of the liners. That is what seals them to the head gasket. The problem is that if the cylinder liner is overheated to really high temps the compression in a diesel can be high enough to deform a liner. When they get deformed they bulge in the middle and shrink top to bottom where they are clamped in by the head. Then they do not have the required protrusion into the head gasket and off we go to another overheat and failure. In fact this is one of the reasons for the first failure sometime. It happens on gas engines as well with way lower compression ratios.

So in light of everything the best thing to do is remove it and either replace it with a rebuilt one or have this one rebuilt by someone that knows what they are doing. A couple of liners, new rings and a new crank will drive this past a re-man unless they are able to do the work on their own.

 

[LWW]

Which side of the country are you on. I would sure like to make a deal on a replacement for that 120 with a 135 lehman.Larry

 

[bfloyd4445]

This is true of gas engines that have liners as well. A big problem is that an over heat will cause a slight problem that then grows into a head gasket replacement. The replacement is done by a brother in law, friend or owner that knows not about liner engines and when they remove the head they do not break the head away from the block properly or secure the crank from rotating when the head is off the engine. One or the other if not both result in a lower seal going bad where the liner seals to the block. But of course this goes unnoticed. The new head gasket is installed and the engine will sooner or later over heat once again but his time because the liner seal leaked anti freeze into the oil. Game set and match.

i thought i read some where that only some lehmans have liners?

 

[JAT]

i thought i read some where that only some lehmans have liners?

Many diesels have liners.... Perkins, Cummins....for a couple...

 

[jleonard]

Quote:
Originally Posted by bfloyd4445
i thought i read some where that only some lehmans have liners?

Many diesels have liners.... Perkins, Cummins....for a couple...


Cummins B series does NOT have liners, it is a "parent bore" engine.
According to my Lehman book, engines built in 1970 and newer do NOT have liners.

 

[JD]

Cats as well.

 

[BruceK]

Cats as well.

Cats have liners for litter boxes too.

 

[bfloyd4445]

Many diesels have liners.... Perkins, Cummins....for a couple...

I know that but when researching lehmans I found a note that mentioned only certain serial numbers had liners and most didnt. My point being that you can't be sure untill you break her down so it is best to treat the engine like it has a liner unless you know absolutely sure that it dosen't

 

[lst-1164]

lehman 120

Which side of the country are you on. I would sure like to make a deal on a replacement for that 120 with a 135 lehman.Larry

boat at satelite beach fl

deal on replacement

thankyou bob b.

 

[LWW]

I sent you a msg LST 1164. Hope I did it right. let me know.Larry

 

[BruceK]

badu11, Long time not hearing from you.
Busy tearing your hair out with all the suggestions?
Can you tell us what you finally found, how you decided to fix it, and your progress?

 

[LWW]

Hey Bob. How's that lehman coming. What did you find out on teardown.Larry

 

[lst-1164]

lehman 120

crank and head at machine shop

head gasget , crank bearings ng

will rebuild

thanks for input

bob b.

 

[LWW]

That's great. I'm glad it was fixable and you can get back on the water.Larry

 

[bfloyd4445]

yes, we are all chomping at the bit waiting for an update

 

[roguewave]

I'd sure like to know how this turned out hope all is well.

BADU's Last Activity: 02-09-2013 03:08 PM

 

[bfloyd4445]

we are all waiting for news

Hope all is well and repairs weren't to extensive.