Ford Lehman 120 -Oil Level

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Ttsaang

Veteran Member
Joined
Sep 25, 2019
Messages
40
Location
Canada
Vessel Name
Ttssang
Vessel Make
1974 Roughwater 35
Does anyone know of a diesel mechanic that knows old Ford Lehman's in the Black Creek, Campbell River, Courtenay, Comox area? I have a question about the oil level and I'm going to post a picture of my dipstick. I've read other posts that mention the engine being on an angle and the full level being at the scratch mark on the dipstick. I just purchased this boat and during the sea trial the oil level was at the normal full mark and not at the angled scratch mark on my dipstick. The boat has not been used much in the past year and there was some white smoke at start up and some oil in the exhaust. I changed the oil and put in approximately 14.5 litres and the mark is now at the original Min level but above the lower scratch mark. I still think I may have too much oil in the engine. The oil pressure is hovering between 30 and 40 psi when running at 1700 rpm and the engine temp is steady at 195. There's a small trace of oil in the exhaust. Any advice is appreciated.
 
I would call Brian at American Diesel 804-435-3107. His dad was the Lehman all time guru before he passed away. Now Brian is the man. I think that he will tell you to drain the oil and put in the specific amount then mark the dipstick. I have 225s and mine take 22.5 quarts. The 14.5 liters sounds high to me but I am not absolutely sure about a 120.
 
Local mechanics that don't have the Lehman history down are just local mechs.

More research is needed if they can't answer simple questions about the engine.
 
Greetings,
Mr. C. "...mine take 22.5 quarts. The 14.5 liters sounds high to me..." 14.5 liters is 15.3 US quarts.
 
+1 on contact with Brian at American Diesel. If anyone can be considered a Lehman expert it is him. His dad was one of the persons responsible for marinizing the Ford diesel engine and creating the Lehman, and worked side by side with him at American Diesel supporting all of us.

If you have a Lehman 120 it is most likely the 2715E, that will be on the metal plate on the valve cover, somewhat like the one below...

20180909_150433.jpg

The FL 120 takes 12 quarts (3 gallons US). That would be approximately 11.4 liters.

Lehman oil capacity snapshot.jpg


Here is the relevant section from the FL manual about checking the oil and the remarking of the dipstick due to the engine not being installed level...

Lehman oil dipstick snapshot.jpg

I just uploaded a very good quality scan of the Lehman manual to this site that I had found. The above two screen captures are from it. Here is the link Trawler Forum - Library - Lehman 120 - Good Quality Scan

What the above tells you is that basically, after changing the filter, you should put in 12 quarts, run the engine, allow it all to drain through, and there should be a full mark at where the oil is sitting in the engine in your boat.

The original full mark becomes irrelevant when the engine is tipped and the oil now occupies a different footprint in the oil pan. I don't have a picture here at the house, but IIRC the factory full mark is above my "adjusted-as-installed" marks. I would suggest you pull the oil back out, and put in 12 qts and see what it lines up with.

Post a pic of your dipstick even better if you have more questions.
 
Greetings,
Mr. Tt. We have twin Lehman 120's. I also have the scratched-in mark on both dipsticks. One "problem" I had in the past is that if I filled to the scratch level I would very quickly lose (probably burnt) 1 qt in a very short period of time (about 10-15 hrs). Initially I was diligent about keeping the oil topped up but still that loss of 1 qt.



At one oil change, I left the oil level 1 qt "low" and that level stayed the same for most of the next 100 hrs or so. This suggests to me that the scratch is in the wrong place on MY engines and I was overfilling. I now fill/maintain at the lower level.


I still have to add oil on occasion but I am better able to sense what is "normal". Daily ER fluid checks and general ER checks every 4 hours or so while cruising.


Also keep in mind that you can never drain all the oil out of the pan due to the mounting angle. I don't know how much might be retained but that will have an effect on the replacement volume, as well. I'm guessing in my case it's probably that 1 qt.
 
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Keep in mind that there have been cases where the wrong dipstick has been installed so the marks are way off. I also find that if I don’t keep my oil to the top mark I don’t loose as much oil. When I top them off they always burn about 1/2 quart so I don’t top them off.
 
Thanks for all the replies, I'm about to read through them. Here's some pictures. When I check the oil, the full line at the moment is at the top part of the M in Minimum.
Another question, I changed the engine mounted fuel filters and the white plastic bleeder on one of them seems a little cross threaded and difficult to thread back on. Is this something I can get from American Diesel or is there a place on Vancouver Island I can order from?
 

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My secondary fuel filters are not like that so I don’t know about the plastic piece. BTW, do you know about changing the oil in your injector pump? It is recommended at 50 hours to start with until you learn how soon your engine dilutes the oil. Be careful with the screws I understand they are easy to strip.
 
Yes I changed the oil in the injector pump.
 
My scratch is the same as yours, about 3/4 of an inch below the "M". I HATE those plastic drains on the secondary fuel filters. Next time I have mine apart I intend to replace them with a brass valve with a barbed fitting leading to a short piece of hose. I always spill some when I drain the filters prior to changing them. I have a similar set up on my Raycors and it makes filter changes possible without spilling a drop. It took me a few changes to figure it out. By the way, my primary filters are mounted sort of high so there is good flow when I drain them.

pete
 
Do you use the scratch as your full mark?
 
Not rocket science. Drain oil pour in 3 ga. Run ,shut off mark dipstick.
 
Oil level update

So I drained my oil and put back in 11.4 litres (12 quarts) my oil level is now right at the scratch mark, even at the same angle.
The motor has 975 hours on it, when I bought it it had 930 hours. I notice from the past logs that the previous owners have been overfilling the oil by quite a bit for the last couple of oil changes, maybe longer. When I had the mechanic check over the motor during the purchase I noticed some oil in the exhaust, the mechanic said not to worry that the boat had been sitting for a long time. To bring the boat home when I bought it I had to travel approximately 75 NM. Every time I started it I noticed a little oil coming out in the exhaust. (oil pressure is always around 30 psi and water temp at 195) Now that I have the oil at the proper level I'll see if I can get out for a trip and see if there's still oil in the exhaust. I would prefer to not have any oil in the exhaust and I'm wondering if having it overfilled all that time has caused any damage to the engine or if there's anything I can do besides keeping the oil at the proper level to mitigate any damage or wear? Any advise or input is appreciated.
 
How do you know its oil and not fuel in the exhaust? They both make a sheen on the water.
 
Good point, I don't know if it's oil or fuel. from my logs I see that my injector pump was re-built in the last couple of years. I've also been reading further and I see that it's common for these FL 120's to have a sheen at start up. I will monitor the situation.
 
The 11.4 sounds much better. I doubt that it hurt the engine, Lehmans seem to push out the extra until it gets to the level it wants. Good luck.
 
Good point, I don't know if it's oil or fuel. from my logs I see that my injector pump was re-built in the last couple of years. I've also been reading further and I see that it's common for these FL 120's to have a sheen at start up. I will monitor the situation.

The sheen is unburnt fuel. The amount will vary with engine temperatures. Keep in mind that the Lehman’s run cool, especially at idle. Will only reach operation temperature under load. You will almost always see a sheen at idle.
 
If the engine was overfilled with oil then some of the sheen could be oil but I agree that there will be some fuel in the discharge. Maybe a mixture of both. But now that it is filled to the proper level of oil then maybe the sheen will be less.
 
My hubby and I are under contract for a 38' Marine Trader with a Lehman 135. He called American Diesel and had the exact conversation you laid out. According to Brian, the tilt on the engine does result in it being overfilled if it's filled to the original mark on the dipstick. Then the engine blows out the excess, owner refills, repeat. Brian says to drain the oil, refill with what is called for exactly in the specs (14 qts in our case) and then to remark the dipstick and keep the level there. Sounds like someone's already done this for your dipstick, so you may just want to verify that the mark's right at your next oil change and stick with that.
 
My two Lehman 120s always managed to get rid of the excess oil I had in them (until I learned better in the pre-internet days) by leaking it out into the drip pans. I was told that any excessive engine oil coming through the exhaust at idle would show up more like droplets hitting the water and spreading than the normal even sheen unburnt diesel displays. I cannot verify the veracity of this claim.

So changes I made over 29 years of ownership:

Got rid of those awful engine-mounted filters and replaced with a kit from Parker to allow a spin-on filter with a transparent bowl.

Changed the Racor 500 bowls to ones with the extra bulge for mounting a water sensor and wired in the Parker water sensor alarms to engines and genny Racors.

Replaced the injector pump drains with petcocks. My Simms pumps took exactly 2 cups to fill - never removed the overfill bolt again after that was established.

Replaced the original Lehman radiator caps with kits from American Marine for a double acting cap with a recovery bottle.

Replaced the sump plugs with hose connections to an electric oil change pump.

Replaced the original above engine muffler system (hopefully these abominations have been purged for all FL 120s nowadays) with lift mufflers.

Replaced all the black cooling hoses with blue silicone.

Replaced all coolers with high quality one made of cupronickel.

Added ball valves at the two points on the engine where the cooling water exited and reentered from the water heater in case there was ever a leak in that circuit.

It is probably time for you to re-torque the head bolts and while the valve cover is of, check the valve clearances and hammer the valve cover flange flat using a steel ruler as a guide (to prevent nuisance oil leaks down the side of the engine - only 22 INCH pounds on the torque wrench to re-tighten the eight screws).

Be watchful for the first signs of rusty drippings from the bottom of the exhaust elbows onto the heat exchangers. That's time to change them, and it is not difficult unless you get a stuck bolt which a mechanic with an oxy torch can help you remove after you break it (Yes! I did :() Change both engines at once and put anti-seize on the four bolt threads when reassembling.

Pull the injectors for reconditioning before 2000 hours. Use new copper crushing washers in the bottom of the injector holes and on the return fuel banjo connections.

Use straight 30 weight oil, never synthetic or multi-weight. 40 weight if you will be in really hot waters, but here in north FL, I never needed it - 30 was fine.

50-50 ethylene glycol (Prestone for mine) coolant.

Lehmans return so little fuel that an installed polishing system becomes a fine idea to avoid contamination issues down the road. BTW, I used 2-micron Racor filters and had vacuum gauges remotely mounted from tees downstream of them so I could monitor them from the helm. With polished fuel, I went a year or two between Racor filter changes and five of more years for the spin-ons mounted on the engine.

There are likely a dozen other things I am not remembering right now, but I am always happy to shoot the sh__ about these great engines.
 
Another question, I changed the engine mounted fuel filters and the white plastic bleeder on one of them seems a little cross threaded and difficult to thread back on. Is this something I can get from American Diesel or is there a place on Vancouver Island I can order from?

Yes, call Brian at American Diesel. He has them. Had the same situation on my SP135's. Been talking about changing these out to spin ons for....going on 2 years? One day....
 
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Lehman 120

Does anyone know of a diesel mechanic that knows old Ford Lehman's in the Black Creek, Campbell River, Courtenay, Comox area? I have a question about the oil level and I'm going to post a picture of my dipstick. I've read other posts that mention the engine being on an angle and the full level being at the scratch mark on the dipstick. I just purchased this boat and during the sea trial the oil level was at the normal full mark and not at the angled scratch mark on my dipstick. The boat has not been used much in the past year and there was some white smoke at start up and some oil in the exhaust. I changed the oil and put in approximately 14.5 litres and the mark is now at the original Min level but above the lower scratch mark. I still think I may have too much oil in the engine. The oil pressure is hovering between 30 and 40 psi when running at 1700 rpm and the engine temp is steady at 195. There's a small trace of oil in the exhaust. Any advice is appreciated.


12 quarts sounds right. I’m traveling or I’d verify that. However, your motor should be at 180. 195 is to high. I’d have your thermostat checked. Also, might be time to flush out your entire cooling system. Your heat exchanger is probably full of scale and crud.
Also, add me to the list of those recommending that you call Brian. He will tell you that you drain the oil, fill it to the recommended amount then mark your dipstick accordingly. He is the best source of info on the FL 120.
 
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My hubby and I are under contract for a 38' Marine Trader with a Lehman 135. He called American Diesel and had the exact conversation you laid out. According to Brian, the tilt on the engine does result in it being overfilled if it's filled to the original mark on the dipstick. Then the engine blows out the excess, owner refills, repeat. Brian says to drain the oil, refill with what is called for exactly in the specs (14 qts in our case) and then to remark the dipstick and keep the level there. Sounds like someone's already done this for your dipstick, so you may just want to verify that the mark's right at your next oil change and stick with that.

Welcome aboard. Congrats on your new boat. Brian is an invaluable resource.
 
The 11.4 sounds much better. I doubt that it hurt the engine, Lehmans seem to push out the extra until it gets to the level it wants. Good luck.

This phenomenon is not limited to Lehman’s, all diesel motors will do this until you find their “happy place” and stop overfilling them.
Many boat owners are obsessed with keeping the oil up to the mark, and create all kinds of nasty problems by doing so.
I bought a great Cummins with 500 hours on it that the owner insisted was on its last legs due to excessive blow-by. I ran it for another 6000 hours, with no blowby problems when filled to the correct level!
Current owner says it’s still fine, it must be near 10,000 now.
 
Rich Gano summed it up very nicely. I learned of a few more things to do to mine when it comes time to change the hoses.

If you google "Trawler Beach House" there is a complete description on changing your oil with pictures and tips. I found it helpful when first doing it the first time.

Your engine running warmer then recommended could also be from having a bit of air in the system Should be a valve on the top of the manifold to bleed the air out.
 

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