120 lehman oil usage

I was wondering what the normal oil comsumption on a 120 is?** I have been running for a week now putting on 87hrs on my old 120* used about 2-3 quarts oil* Alittle smoke at start up other then that seems clean


-- Edited by motion30 on Monday 24th of October 2011 03:27:24 PM

Try running with the oil level at "min" and see if it still uses oil.

*

Has the dipstick been recalibrated? For Lehmans, at an oil change, you need to add exactly what Lehman calls for, then re-mark the dipstick. If you have too much oil, it'll slosh, aerate and burn oil. This is because the factory dipstick was calibrated for the engine on a level platform, and it's tilted in your boat.

Our 1973-vintage FL120s use the same amount of oil today as they did when we bought the boat 13 years ago. The port engine uses about 1/4 of a quart of oil between oil changes, which we try to do every 100 hours but sometimes go as many as 150 hours. (The FL120 operators manual calls for an oil change interval of 200 hours).

Our starboard engine uses about a quart and a half every 100-150 hours BUT..... most of that is from a leak around the fuel lift pump that I've simply been too lazy to fix. The FL120 has a reputation for developing a weeping leak around the fuel pump because of the configuation of the gasket between the pump body and the block. When the day comes, probably this winter, that we replace this gasket--- or have it replaced--- I suspect the oil consumption will go back to being what it was before the leak developed, which was a half a quart or less every 100-150 hours.

It's normal for an FL120 to smoke some on startup-- if it doesn't there's something wrong with it * But the smoke should fade away within a few minutes of startup.* It's also normal for the engine to put a sheen of unburned fuel on the water out of the exhaust--- this is the result of incomplete combustion when the engine is cold.* It, too, should go away as the engine warms up.

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-- Edited by Marin on Monday 24th of October 2011 07:28:47 PM

yes the dipstick has been adjusted That was running 10-12 hrs each day so that was 2 qts running 7 days I am ok with this no smoke while running*** I have put over 1500hrs on this old girl in the past 3 years and she has not missed a beat. 1973 vintage


-- Edited by motion30 on Monday 24th of October 2011 08:02:10 PM

"Normal" oil consumption should be around 0.1 percent of fuel consumption or about 12 or 13 ounces for every 100 U.S. gallons of fuel.

If yours is considerably higher there is something going on and if it is considerably lower I would look for fuel dilution.

RickB wrote:
"Normal" oil consumption should be around 0.1 percent of fuel consumption or about 12 or 13 ounces for every 100 U.S. gallons of fuel.

If yours is considerably higher there is something going on and if it is considerably lower I would look for fuel dilution.

Click to expand...

210HP Cummins: *I'm consistently adding 1 qt of oil per 500 gallons consumed, or about 6.4 ounces for every 100 gallons of fuel.* While this has always amazed me that it is*so little, the oil analysis at every oil change indicates no fuel dilution.*

This may be the bottom of the normal range for this engine.

An important point is WHEN to measure the oil.

On a COLD ENGINE THAT HAS BEEN SITTING?


ON A JUST SHUT DOWN engine?

Da Book will tell what the preferred method is , look it up!

ON our DD 6-71 its 3 min after shut down , which gives a WAY!!! different reading from cold sitting.

Running low on purpose to slow leaks is very risky with out a Murphy or other auto secure system installed.

You are betting the engine on the frequency of your scan.

Jay N wrote:.
210HP Cummins: *I'm consistently adding 1 qt of oil per 500 gallons consumed, or about 6.4 ounces for every 100 gallons of fuel.* While this has always amazed me that it is*so little, the oil analysis at every oil change indicates no fuel dilution.*

This may be the bottom of the normal range for this engine.

Click to expand...

*When I had my Cummins 6BTA 270 in my Mainship I would not add anything between changes which would be* 200 hours and close to 600 gallons of fuel. It might be down 1/2 quart. The old Perkins 160 that I replaced in that boat would use all of that .1*% discussed, probably closer to .2%. I never kept track in my current Lehman but I suspect it's a lot more than .1%.

*

Like FF wrote, it depends on when you check, consistency is critical. Oil expands around 7 percent between a "cold" engine and one at operating temperature. A lot of oil clings to the parts and doesn't show up on the dipstick for quite a while after shutdown.

It is impossible for an engine NOT to consume oil.

RickB wrote:
Like FF wrote, it depends on when you check, consistency is critical. Oil expands around 7 percent between a "cold" engine and one at operating temperature. A lot of oil clings to the parts and doesn't show up on the dipstick for quite a while after shutdown.

It is impossible for an engine NOT to consume oil.

Click to expand...

I have noted some differences in my engine performance since I started running slower and cruising a lot on one engine. *I used to run between 2500 - 2800 RPMs and now run 2100 to 2200. *(These are 6.354 na Perkins.) *

(No, this is not a money saving move, just getting older, more relaxed and enjoy a quieter running boat.) *

Since I started running slower speeds and more on one engine over the last couple of years, I have noticed that my lube oil consumption has gone from a quart every 25 hours to nearly nothing. *I'm burning about one quart between oil changes now, 200 hours, and I notice the engines smoke less on startup and while cruising, *Is this a result of engine loading?


-- Edited by Edelweiss on Wednesday 26th of October 2011 07:53:32 AM

I agree w Rick. The fact that your engine burns oil is not a bad thing. One needs to know under what conditions and what is normal for that engine. Old Jaguars burned much more oil than most American auto engines did so when people bought Jaguars they got worried about what seemed like a lot of oil consumed. As I recall the Jaguar engines of the time had oil control rings that left much more oil on the cylinder walls than most other automotive engines so the pistons and cylinders had plenty of oil for good lubrication when the engine worked hard. The engine was expected to experience high loads and high speeds frequently and Jaguar had it's reputation to protect. In a boat engine that you're going to work hard (hopefully) zero oil consumption would be cause to be concerned. Rick correct me if I'm wrong but I think a good test of rings is a leak down pressure test done skillfully on an engine without glazed cylinder walls. Grade A on that test along w having normal oil consumption should show that the engine was in good condition.

Also, the British used oil as a contributor to engine cooling as well. For example, the 70 hp 2.25 litre petrol engine in my 1973 Land Rover (an engine that was designed as a diesel in the 1950s), has a sump capacity of two gallons of oil. This is way more than is needed for lubrication alone.

I don't know if these high sump capacities and cooling function of the lube oil contributed to higher oil use or not.

Of course, the British were the first to discover the many benefits of what became known as the "Total Loss" lubrication system. Perfected in engines like the Rolls Royce Merlin that was used in the Supermarine Spitfire, the total loss oil system was quickly adapted by the British car industry. The theory behind the system is simple. If the engine is designed to leak oil, the operator will have to be pouring new oil in on a regular basis. Thus, the oil in the engine will remain much cleaner than if the engine didn't leak and the same oil stayed in circulation throughout the oil change interval. The British automotive industry used this system with great success and reliability until the car manufacturers began being acquired by foreign companies who began using their own engines in the cars. When Land Rover, for example, was acquired by BMW, they stopped using the Rover-designed and manufactured engines which experienced negligable engine wear due to the continuous replenishment of dirty oil with clean oil and substituted BMW engines, which, while they didn't leak, had very long oil change intervals and at 150,000 miles or so suffered from severe crank and cam bearing wear. The old Rover engines, like the one in my Land Rover, were barely broken in at 150,000 miles.

The Ford or Englane Dorset diesel that was marinized by Lehman is a prime example of an engine designed from the outset with the Total Loss lubrication system.* Leaks oil very nicely, and typically goes 12,000 to 14,000 hours (according to American Diesel) in recreational boat service before needing an overhaul.

Surprisingly only one US vehicle manufacturer recognized the value of and adapted the British Total Loss lubrication system, and that was Harley-Davidson. Sadly, they no longer use this system.

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-- Edited by Marin on Tuesday 1st of November 2011 02:14:02 PM

*I was glad to see that little smiley face at the end of that!

*

For a long time (having grown up on Air Force bases) I thought Pratt & Whitney invented the method.

Flying a C-45 across the Rockies 10 times a week did nothing but reinforce the belief that even if they didn't invent the technique, they perfected it.

"I notice the engines smoke less on startup and while cruising,"

White smoke on start up is unburned fuel OK if it leaves rapidly ..

The Temperature at which it leaves can help tell engine state.

If it leaves rapidly ,(one or two min) the compression is fine , if it takes 140F or more the compression is suspect.

Black smoke underway is an engine with too much fuel, Overload , restricted intake or exhaust.

Motion30-

Check carefully around your engine for oil leaks. Many Lehman 120s have some oils leaks. Common areas are

back of eninge near the heat exchanger - could be head gasket or the head itself.

stbd side front motor mount - could be from fuel injection pump. Cant do much about this one.

Rear seal - oil will accumulate in bell housing and drip out the very lowest point. You MUST be sure you have the bolt out at the bottom of the bell housing to drain this oil. This is a Bob Smith recommended maint. action.

Fuel Injection Pump - common oil leak area. Only two bolts clamp the pump to the engine block. Common leak area.

Oil diapers under the engine will tell you about oil leaks and show you where to start looking.

R.

Marin if you're going to talk about something as foreign as a total loss lube system I think you should give more hint's as to what you're talking about. The only vehicles I've had that probably qualifies is 2 stroke engines and a 1934 Harley I had in 1959. The tanks between my legs were two halves as typical of Harleys but this one had lube oil in the right half. There was a knob like on a Coleman lantern for air pressure on the top of the tank. No smoke in the exhaust meant it was time to pump oil w the knob. Used oil drooled out on the road when you depressed a plunger on the crankcase. Is that what you're talking about? That's very crude. You're sad that it's gone?

Most of the early jet engines used total loss lubrication systems with bleed air used to spray the bearings with an oil mist. The rotary engines of WW1 used a total loss system of castor oil that was slung outward and kept the pilots regular.

nomadwilly wrote:
Marin if you're going to talk about something as foreign as a total loss lube system I think you should give more hint's as to what you're talking about. ....Is that what you're talking about? That's very crude. You're sad that it's gone?

Click to expand...

*Eric--- There is no such thing as a Total Loss lubrication system.* It's a tongue-in-cheek explanation I was given at the Land Rover factory during a trip to the UK*for the habit of older British engines to develop so many oil leaks as their gaskets and seals wore out.

Total Loss Lubrication Systems:

*

http://www.skf.com/portal/skf_lub/home/products?contentId=868484

http://www.rotaryeng.net/Wankel-CC-paper.pdf* (page 10)

http://www.dropsa.com/flex/cm/pages/ServeBLOB.php/L/EN/IDPagina/839

http://www.gasturbine.pwp.blueyonder.co.uk/NPT301.htm

http://www.century-of-flight.net/new%20site/frames/rotary%20engines_frame.htm

http://www.scribd.com/doc/48258552/eBook-Aviation-Gas-turbine-turbojet-turbofan-Rolls-Royce-The-Jet-Engine* (page 76)

I would have never guessed there was actually something called a Total Loss Lubrication system. The "explantion" given to me at Land Rover was in jest and based on the propensity for older engines, particuarly older generation British engines, to leak oil like sieves as they aged. As the oil leaks out onto your driveway you have to keep pouring new oil in.

I guess that "explanation" was based on somehing real, albeit not a system designed to take advantage of the oil leaks an old engine devlops.

Guys the closest thing to a total loss LO system that is still around is the cylinder lubrication of a large cross head diesel engine such as those manufactured by Man B&W
and Sulzer (now owned by Wartsila).
The cylinder lubricant (different oil to the crankcase oil) is injected into the walls of the cylinder liner to libricate the piston.
This oil is used and burnt completely and an engine such as a Sulzer 7RND 90M (7 cylinder 27000 HP 900 mm (36")bore) used approx 200 lts per day. I am a bit rusty on the figures.
There are still thousands of these engines at sea.

Tidahapah wrote:This oil is used and burnt completely

Click to expand...

It's been a while since you mucked out a scavenge space, eh Benn?

Suzuki had oil injection into the ring lands at BDC on some of their 2 strokes. But of course all 2 strokes are "total loss" except DD.*

*

And the engines Benn was talking about, those are 2-strokes. They are the most powerful engines on the planet and they are the most efficent diesels ever built.

Here are some pictures of some work being done on an 11 cylinder 66,400 hp version that weighs around 1700 tons and drives a 66000 ton containership at 25 knots.

The first picture shows hydraulic "jacks" in place on the bolts that hold the lower end of the connecting rod to its lower bearing half.

The next one shows half a main bearing shell.

The last one shows the cap that holds that bearing.

RickB wrote:
And the engines Benn was talking about, those are 2-strokes. They are the most powerful engines on the planet and they are the most efficent diesels ever built.

Here are some pictures of some work being done on an 11 cylinder 66,400 hp version that weighs around 1700 tons and drives a 66000 ton containership at 25 knots.

The first picture shows hydraulic "jacks" in place on the bolts that hold the lower end of the connecting rod to its lower bearing half.

The next one shows half a main bearing shell.

The last one shows the cap that holds that bearing.

Click to expand...

Would just about fit in my machinery space (if I took out the machiney).

Thanks Rick,
Being on Rig Tenders these days didn't have any photos of the good old days at hand. (a lot of CAT 35Bs etc plus Wartsilas on the bigger units)
Still remember scavenge space and clean outs but for me that was a long time ago, I didn't do piston /ring inspections until the boys had completed the cleaning.
Guys FYI one could crawl down the exhaust trunk of these engines and carry out a piston inspection and partial ring inspection by turning the engine.
The good old days .

Yeah, "good old days" look a lot better from a distance.

It has been a while since I was involved in a piston pull or tensioning through bolts and, you know, I don't really miss it. Glad I had the experience but not too keen to do it again.

My "chief mate" just departed Guam headed for China on a boxboat so I am sure she will soon be telling me about everything I am missing.

Well that's something to crow about.

"2 stroke engines are the most efficient engines on the planet"

I do'nt think my Evinrude e-tech burns less than the 4 strokes but it's very close. And the lube oil is always fresh and clean. What kind of scavenging systems are employed on those monster 2 strokes Rick?