Ford Lehman 120 oil coolers

[Lollygag]

The oil and tranny coolers on my FL120s don't have a date on them for when they were installed. Now seemed like a good time to replace them because they are an unknown I can fix. The maintenance manual says to replace them every two years but a mechanic in the boatyard says that's crazy. So my question is: How often do you replace the oil coolers on your FL120s?

 

[Old deckhand]

When in doubt throw them out. I replace every 6 years.

 

[Marin]

We replace ours when they start looking iffy. We always use the cupro-nickel coolers. They cost somewhat more but they last a LOT longer.

We have changed our oil and transmission coolers once in the last 17 years.

 

[Lollygag]

Thanks. I'm going to pressure test the ones I replace and keep them as spares. I don't think they have any leaks since I haven't found any water in the oil or ATF. It looks like a couple of them have been replaced in the last few years but the others look a little old.

 

[BruceK]

I have a recollection (possibly faulty), of reading either in the IG Manual or the Lehman Handbook, that replacement is indicated at 2000 hours. I just checked both, and despite not finding the reference still think it is there, somewhere.

 

[Irish Rambler]

I've haven't replaced any in all my 35 years cruising and never had a problem.
Don't fix it if it ain't broke !
If you really feel uncomfortable strip them off, and take them to a local radiator repair shop and they will clean/pressure test/renew 'O' rings for you.
If you insist on having new ones and have trouble finding them locally Google www.ejbowman.co.uk they design, manufacture and supply engine makers/marinisers worldwide with all types of oil coolers, heat exchangers, header tanks, intercoolers etc and they'll send you a replacement.

 

[jleonard]

I am on the 5 to 6 year plan.
One engine so it's relatively cheap.

 

[Larry M]

We replace ours when they start looking iffy. We always use the cupro-nickel coolers. They cost somewhat more but they last a LOT longer.

We have changed our oil and transmission coolers once in the last 17 years.

Yes, on the cupro-nickel! Hour many hours?

[QUOT,E=BruceK;321628]...at 2000 hours...[/QUOTE]

We change ours every 1700-2000 hours and change the transmission cooler at the same time. The oil cooler was less than $200 for the last one I bought and the transmission cooler was less than $135.

 

[kchace]

At $100-$120 each (for a Lehman oil cooler), changing them every 5-8-10(whatever) years is cheap insurance. Unlike a leak in the engine heat exchanger, a leak in an oil cooler will quickly cause damage and you'd be unlikely to catch it in time. If the engine oil or transmission oil cooler started leaking you would either - lose oil and/or mix sea water into the oil. Either would trash the engine or transmission pretty quickly. I just changed out mine since I KNOW the PO did not and he owned the boat for 9 years.

Ken

 

[Wxx3]

The timing that American Diesel says if age is unknown, replace them and keep as spares, which I have done.

Recommended time per AD is 1000 hours to main heat exchanger and 750 for oil and transmission (which are the same).

I replaced mine just before the Atlantic crossing and other then some weeds at the front, it looked great. At that point is had >1500 hours on it.

 

[Larry M]

...Recommended time per AD is 1000 hours to main heat exchanger and 750 for oil and transmission (which are the same)...

Richard: Those numbers seem low. My notes from AD say 2000-3000 hours on the heat exchanger and 1200-1500 on the oil/transmission coolers.

Greg at Bomac Marine recommends every 4 years on the heat exchanger and every 2 years on the oil/transmission coolers. Greg says hours aren't the issue but time is. He suggested that corrosion through electrolysis is what dictates life span.

As Ken mentioned previously coolers are cheap as compared to the damage they do if they fail.

 

[waddenkruiser]

As long as they run - don't tinker.

(I'm nocking on wood, never changed them on my boats, up to 40 years of service)


best regards / med venlig hilsen
wadden

 

[Marin]

Many of the oil and transmission heat exchangers sold today for engines like the FL120 do not have the ability to install a zinc anode, nor do they have connection points to tie the exchanger into the boat's bonding system. The cupro-nickel exchangers we use are like this.

Our diesel shop taught me a smart way to tie the heat exchangers into the boat's bonding system by removing the paint from the barrel of the exhanger where the metal mounting bracket clamps around it. Then I remove the paint, or clean to bright the insides of the two part clamp itself. This electrically connects the heat exchanger to the engine block, which is in turn connected to the boat's bonding system.

Since doing this the outside and inside of the oil and transmission heat exchangers (they are all identical units) remain as pristine as the day we bought them.

 

[Capt.Bill11]

At $100-$120 each (for a Lehman oil cooler), changing them every 5-8-10(whatever) years is cheap insurance. Unlike a leak in the engine heat exchanger, a leak in an oil cooler will quickly cause damage and you'd be unlikely to catch it in time. If the engine oil or transmission oil cooler started leaking you would either - lose oil and/or mix sea water into the oil. Either would trash the engine or transmission pretty quickly. I just changed out mine since I KNOW the PO did not and he owned the boat for 9 years.

Ken

While I agree coolers should be changed before they go bad, I've lost track of how many coolers on Lehman's I've seen go bad and I don't recall ever seeing one trash an engine or tranny.

So it's not automatically the end of the world if one goes bad.

 

[Lollygag]

Many of the oil and transmission heat exchangers sold today for engines like the FL120 do not have the ability to install a zinc anode, nor do they have connection points to tie the exchanger into the boat's bonding system. The cupro-nickel exchangers we use are like this.

Our diesel shop taught me a smart way to tie the heat exchangers into the boat's bonding system by removing the paint from the barrel of the exhanger where the metal mounting bracket clamps around it. Then I remove the paint, or clean to bright the insides of the two part clamp itself. This electrically connects the heat exchanger to the engine block, which is in turn connected to the boat's bonding system.

Since doing this the outside and inside of the oil and transmission heat exchangers (they are all identical units) remain as pristine as the day we bought them.

I never thought of that! I've replaced one so far but now I'll remove it and clean the barrel and clamp. Then I'll do the others.

 

[FoxtrotCharlie]

Not to hijack the thread, but what would you guys consider high hours on a Lehman 125hp engine? I'm about to look at a boat with 5200 hrs - initial online look seems to be well maintained - clean ER

 

[Marin]

There is the FL120 and the FL135 but I've not heard of an FL125.

The FL120 is said to be a 12,000 to 14,000 hour engine in recreational boat service assuming proper operation, service, and maintenance. But that's kind of a number out of a hat. I know of FL120s that crapped out with less than 3,000 hours and examples that have gone more than 25,000 hours before needing a major overhaul.

So the number of hours on an FL120 is sort of irrelevant. What IS relevant is how the engines were treated by the people who've been running them.

Depending on that, an FL120 could be about ready to die with 5,200 hours on it, or it could have 10,000 or more hours left to go. You need to try to learn how the engines were treated and have a QUALIFIED engine surveyor give them a thorough checkout.

That's what we did with our PNW boat. We believe in getting two surveyors to check out a prospectve boat, a hull/systems surveyor and an engine surveyor intimately familiar with the type of engine we're considering. We did our research and that plus a good friend whose entire career has been in the marine diesel and generator manufacturing industry located supposedly the best FL120 surveyor in the SFO bay area and we hired him to check out the engines and generator of the boat we subsequently bought.

In our case the engines had very low hours for the age of the boat, and that concerned us. The explanation was totally plausible but we wanted to confirm the engines' condition for sure.

If the engines you're looking at are FL135s I have no experience with that model of Ford engine (Dover) so can't offer any speculation or advice about them.

 

[FoxtrotCharlie]

Many thanks Marin - yep, I will definitely get engine surveys if I choose to proceed. Owner has oil analysis records, so we'll have a starting point for new analysis comparison. Thanks again.

 

[mike66]

Not to hijack the thread, but what would you guys consider high hours on a Lehman 125hp engine? I'm about to look at a boat with 5200 hrs - initial online look seems to be well maintained - clean ER

Our 135 has 8500hrs and going strong. Might want to start a new thread and maybe survey to find out other peoples experience. Worst case scenario is you replace. Factor that into what you're comfortable paying for the boat.

 

[FoxtrotCharlie]

Thanks - just got more info - the engines are Lehman 2715E - 120hp. Boat is 1983. Is this an older model. From what I can tell they were made in Holland. Now, i think the hijack is complete

 

[Capt.Bill11]

Not to hijack the thread, but what would you guys consider high hours on a Lehman 125hp engine? I'm about to look at a boat with 5200 hrs - initial online look seems to be well maintained - clean ER

5200 is not at all high hours on a well maintained Lehman.

 

[Marin]

FoxTrotCharlie---- A little background info on the FL120 for you....

The FL120 is based on the Ford of England Dorset diesel which was designed in the late 1950s to be a truck diesel. It proved to be a complete failure as a truck engine for several reasons and Ford was on the brink of discontinuing the engine when someone suggested trying it in an industrial application like a crane or pump or generator. At constant, medium rpm (1500-1800) and constant, medium load it proved to be a very good, very reliable engine.

So Ford of England gave it a new lease on life as an inductrial/agricultural engine. In fact, some people in the UK still refer to this engine as the "Combine Engine."

The characteristics that made it a good industrial/agricultural engine made it ideal for marine use, and a number of companies around the world developed and sold marinzation kits for the Dorset diesel. One of these was Lehman in New Jersey, and they eventually became the most prolific and best known marinzer of Ford of England diesels.

So the base engines in the boat you're looking at were make in England in Ford's engine plant in Dorset (hence the name of the engine). The engines were then sold and shipped to Lehman in New Jersey who fitted their marinzation kit to the engines and then sold them to the boat manufacturer.

Lehman also sold their marinzation kits separately. For example in the early 1970s American Marine (the creator of the Grand Banks line of boats) thought they could save money by buying the Dorset engine direct from Ford, the marinzation kit direct from Lehman, and then mating the kit to the engine on the factory floor next to the boat it was going into. They did this for a few years and then realized it was a false economy and went back to buying the already-marinzed engines directly from Lehman.

There is no difference between an FL120 with the Lehman kit installed by American Marine and an FL120 with the Lehman kit installed by Lehman except in the colors of the engines. Lehman painted all their engines red at the factory. American Diesel painted the engines they marinized with the Lehman kit in Singapore one of two colors: a very nice semi-metallic olive green or a rather annoying (in my opinon) yellow-gold.

The FL120s in our boat had the Lehman kits put on in Singapore, so the enngines were painted the olive green. Somewhere along the line a previous owner repainted them Alpine Green (aka Detroit Green) which in my opinon is a terrific color for an engine. We had the engines in our other cruising boat painted this color before they were installed, and when I get around to overhauling the engine in my 1973 Land Rover I'm going to paint the engine that same green.

The photo below is what an FL120 as marinized with the Lehman kit by American Marine in Singapore looks like in a single-engine Grand Banks.

 

[Irish Rambler]

Just to add a bit more background to Marin's post above.
The Ford diesel was in fact a success here in the UK but the Ford truck itself was a dying breed and has long since disappeared, some of the range was transferred to Iveco light trucks.
The engine fell into a bracket along with DAF, Leyland, Gardner, Cummins for supplying engines for 24 to 28 ton trucks, as the truck weights went up to 38 and now 46 tonnes in the UK the engines were obviously not powerful enough. the trucks now use up to 600 hp and those engines are also marinized, Volvo being one and the Scania in marine version goes up to 800 hp..
The Dorset engine was found to be a very good reliable engine and was consequently fitted to agricultural, plant, gensets etc and made a good marine diesel because of it's durability, in fact some 'blown' and intercooled and used as racing engines in power boats by Mike Bellamy of Lancing Marine who is a well known marinizer in the UK.
All marinizing parts are still freely available and because it has replaceable 'wet' liners it's life is as long as yours if well serviced.
The engines are still made in prolific quantities in Turkey and new ones are still freely available.

 

[Marin]

According to the former Ford of England engineer who told me the history of the Dorset engine during one of our visits to the UK, the Dorset was a disaster as a truck engine from day one. It's weak design could not stand up to the rigors of on-road driving with its constantly changing rpm and load. The in-line injection pump is a particular weak spot, he said, under this kind of service and needed constant overhaul or changeout. He didn't comment on the rotary injection pump that was sometimes fitted to this engine.

His comments were confirmed and reinforced by another aquaintence in the UK who for decades owned a large shop that specialized in the servicing, repair, and overhaul of Ford of England engines. He added that if the Dorset overheats, which it frequently did in truck service, the head gasket would immediately blow and the head would almost always warp.

The engine, he said, proved to be much more reliable in constant speed, relatively low and constant load service such as one finds in industrial and agricultural (and eventually marine) service.

Both of these people, particularly the retired Ford engineer, had relatively low opinions of the Dorset diesel. The Dover diesel (base engine for the FL135, is a different story, they said, as it remedied some of the fundamental problems with the Dorset.

While the FL120 has earned an impressive reputation for reliability in marine service, this service makes little demand on the engine's design or strength.

Knowing what we have learned about this engine from people with a long history of being directly involved with it, we would not buy a boat with these engines were we in the market for a used cruiser today. They have several operational characteristics we have learned to dislike, but it's not so much that the FL120 is a bad engine in marine service as it is there are so many superior engines in marine service.

 

[Lollygag]

Finally stuck a camera in the barrel of the oil cooler I replaced. Ya think it was a good idea? Three more to go. If you haven't used your boat recently, you might want to cruise your coolers to a radiator shop.

 

[Capt.Bill11]

Boil it out, pressure test it and save it as a spare. My guess is it's still good.

 

[BruceK]

Finally stuck a camera in the barrel of the oil cooler I replaced. Ya think it was a good idea? Three more to go. If you haven't used your boat recently, you might want to cruise your coolers to a radiator shop.

Yuk. How many hours and years went into making those blockages?

 

[Larry M]

I did engine checks yesterday after running all day and found water in the drip pan (was 1/4 full of salt water). The transmission cooler had a pin hole leak on the salt water side. Fortunately I had another cooler and the leak was not on the exchange side. It had 1322 hours on it and less than 4 years old and yes it was cupro-nickel.


Edit: Cooler was just under 5 years old. The inside looked perfect. We had a corrosion analysis down 2 years ago and everything looked good. So who knows?

 

[RT Firefly]

Greetings,
Mr. LM. A dab of soft solder and I'd say she's good to go. Spare at the very least...

 

[Larry M]

RTF: That was the plan if I didn't have the spare = the one I took off at the last change.


What I'm going to do when we get back is buy 2, install one then the other new one goes into the spare locker. When it's time to rotate or I need a replacement, I'm only doing it once with new.